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Appendix A
Eagle Conservation Plan PSE’s Wild Horse Wind Energy Facility
Eagle Conservation Plan
PSE’s
Wild Horse Wind Energy Facility
Prepared by:
Puget Sound Energy
&
Western EcoSystems Technology, Inc.
June 2019
Draft Pre-Decisional Document - Privileged and Confidential - Not For Distribution
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June 2019 i
TABLE OF CONTENTS
1.0 INTRODUCTION.......................................................................................................... 1
2.0 PROJECT BACKGROUND AND DESCRIPTION.......................................................... 2
2.1 Environmental Setting ............................................................................................ 5
2.2 Initial Consultation .................................................................................................. 7
3.0 REGULATORY FRAMEWORK................................................................................... 14
3.1 Migratory Bird Treaty Act ...................................................................................... 14
3.2 Bald and Golden Eagle Protection Act .................................................................. 15
3.3 National Environmental Protection Act .................................................................. 16
3.4 PSE’s Corporate Environmental Policy ................................................................. 16
4.0 STAGE 1 – PRELIMINARY ASSESSMENT ................................................................ 17
5.0 STAGE 2 SITE-SPECIFIC SURVEYS AND ASSESSMENTS ..................................... 18
5.1 Raptor Nest Surveys ............................................................................................ 18
5.2 Bird Use Surveys.................................................................................................. 21
5.3 Summary of Eagle Use ......................................................................................... 24
6.0 STAGE 4 AVOIDANCE AND MINIMIZATION OF RISK – CONSERVATION AND
MITIGATION MEASURES.......................................................................................... 25
6.1 Conservation Measures benefitting eagles and other protected migratory birds ..... 25
6.2 Additional Conservation Measures ........................................................................ 28
6.3 Wildlife Incident Reporting and Handling System Procedures ................................ 28
6.4 Conservation measures and sage-grouse ............................................................. 29
6.5 Mitigation under the Site Certification Agreement .................................................. 29
6.6 Conservation Easement ....................................................................................... 30
6.7 Adaptive Management under the EIS .................................................................... 30
7.0 STAGE 5 POST-CONSTRUCTION MONITORING ..................................................... 31
7.1 Standard Post-Construction Fatality Monitoring ..................................................... 31
7.2 Formal Eagle Fatality Monitoring........................................................................... 38
7.3 Post-Construction Raptor Nest Surveys ................................................................ 41
7.4 Fixed-Point Eagle Use Surveys............................................................................. 42
8.0 STAGE 3 ASSESSING EAGLE RISK AND PREDICTING FATALITIES FOR WILD
HORSE...................................................................................................................... 44
8.1 Assessing Eagle Use............................................................................................ 45
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8.2 Eagle Risk Factors ............................................................................................... 46
8.3 Fatality Predictions ............................................................................................... 57
8.4 Population Status and Local Area Thresholds ....................................................... 63
8.5 Cumulative Impacts .............................................................................................. 65
8.6 Electrocution Risk................................................................................................. 65
8.7 Categorizing Site According to Risk ...................................................................... 65
9.0 ONGOING MONITORING .......................................................................................... 66
9.1 Operational Monitoring Protocol ............................................................................ 69
9.2 Analysis ............................................................................................................... 72
9.3 Incidental Monitoring Protocol ............................................................................... 74
10.0 OFFSETTING COMPENSATORY MITIGATION ......................................................... 76
10.1 Considerations and Proposed Mitigation Methods ................................................. 77
10.2 Risk Assessment for selecting mitigation poles ..................................................... 80
10.3 Schedule .............................................................................................................. 81
10.4 Retrofit Monitoring and Maintenance..................................................................... 82
11.0 ADAPTIVE MANAGEMENT ....................................................................................... 82
11.1 ECP Adaptive Management Process .................................................................... 82
11.2 Adaptive Management Conservation Measures .................................................... 85
12.0 REPORTING ............................................................................................................. 87
12.1 SPUT Permit Reporting ........................................................................................ 87
12.2 ECP Annual Reporting.......................................................................................... 87
13.0 LITERATURE CITED ................................................................................................. 89
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LIST OF TABLES
Table 2-1. History of avian/wildlife-related agency coordination since Wild Horse commenced
operations .................................................................................................................... 8
Table 5-1. Flight height characteristics for eagle observations recorded during surveys
conducted from May 2002 to May 2003 at Wild Horse................................................. 24
Table 5-2. Number of eagle observations recorded by season during surveys conducted from
May 2002 to May 2003 at Wild Horse. ........................................................................ 24
Table 7-1. Summary of eagle observations (obs) recorded during 310 hours of fixed-point
eagle use surveys conducted at Wild Horse from March 2015 – March 2016. .............. 43
Table 7-2. Summary of eagle observations (obs) recorded during 310 hours of fixed-point
eagle use surveys conducted at Wild Horse from March 2015 – March 2016. .............. 43
Table 7-3. Summary of golden eagle results from eagle use surveys conducted from March
2015 through March 2016. Eagle minutes are defined as the total number of minutes
golden eagles were observed flying within the 0.5-mi (800-m) radius and below 650
ft (200m) AGL. ........................................................................................................... 43
Table 8-1. Qualitative assessment of risk factors listed in the Eagle Conservation Plan
Guidance Version 2 (ECPG Table 1, page 15) as they pertain to the Wild Horse Wind
Energy Facility (see also Section 5.2). ........................................................................ 47
Table 8-2. Inter-nest distances for occupied golden eagle nest sites/breeding areas within 10
miles of the Wild Horse Wind Energy Facility. ............................................................. 50
Table 8-3. Values used to calculate exposure rate (λ)............................................................. 59
Table 8-4. Values used to calculate expansion factor (ɛ). ....................................................... 60
Table 8-5. Values used to calculate the baseline collision correction factor C. Priors were
updated through incorporation of post-construction mortality data in each successive
run of the Bayesian models. ....................................................................................... 60
Table 8-6. Eagle fatality estimates derived from Fatality Capture Mark Recapture (Peron and
Hines 2014) software applied to four years of fatality monitoring data at Wild Horse. ... 61
Table 8-7. Eagle Fatalities per Year (F).................................................................................. 62
Table 9-1. Proposed ECP Monitoring Plan. ................................Error! Bookmark not defined.
Table 11-1. Summary of stepwise adaptive management process for eagle take at the Wild
Horse Wind Energy Facility. Based on a permitted take rate averaging 1.72
GOEA/year and 0.53 BAEA/yeartotaling 9 GOEA eagles and 3 BAEA over a 5-year
permit period. .................................................................Error! Bookmark not defined.
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LIST OF FIGURES
Figure 1. General location of the Facility. ................................................................................. 3
Figure 2. Map of the Project Facilities. ..................................................................................... 4
Figure 3. Habitat map / land use of original Wild Horse Project Area (top panel) and the
expansion area corridors (lower panel). ........................................................................ 6
Figure 4. Digital elevation map................................................................................................. 7
Figure 5. Raptor nest surveys (flight paths) conducted in 2003 (upper panel) and 2006 (lower
panel) in the vicinity of Wild Horse. ............................................................................. 20
Figure 6. Map of bird use survey points and eagle flight paths ................................................ 22
Figure 7. Illustration of standard search plot and transects. .................................................... 32
Figure 8a. Map of Wild Horse post-construction monitoring turbine search plots for 2007. ....... 34
Figure 8b. Map of Wild Horse post-construction monitoring turbine search plots for 2010. ....... 35
Figure 8c. Map of Wild Horse expansion post-construction monitoring turbine search plots for
2012. ......................................................................................................................... 36
Figure 9. Wild Horse search plots for eagle fatality monitoring. ............................................... 40
Figure 10. Eagle nests within ten miles of Wild Horse and turbine locat ions ............................ 51
Figure 11. Rose diagram of prominent wind at the Wild Horse Wind Energy Facility................ 53
Figure 12. Slope calculations for the Wild Horse Wind Energy Facility. Red outlines indicate
areas where slope and aspect, in association with prevailing winds, may create
relatively more consistent updrafts and improved flight conditions for soaring eagles.
Green outlines areas where slope and aspect, in association with
secondary/northeasterly winds, may create updrafts and improved flight conditions
for soaring eagles....................................................................................................... 54
Figure 13. Aspect of the Wild Horse Wind Energy Facility....................................................... 55
Figure 14. WIRHS process map............................................................................................. 75
LIST OF APPENDICES
Appendix A: Elevation, Slope, and Aspect Characteristics of Constructed Turbines at the
Wind Energy Facility
Appendix B: Federal Fish and Wildlife Special Purpose Utility (SPUT) Permit
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1.0 INTRODUCTION
Puget Sound Energy (PSE) is committed to the responsible development, construction, and
operation of its wind energy facilities, balancing the need for clean renewable energy with the
need for wildlife protection and conservation. PSE has a history of working cooperatively with the
U.S. Fish and Wildlife Service (the Service; USFWS), and has implemented a proactive, nationally
recognized avian protection program, including an Avian Protection Plan (APP) which provides
guidance and procedures for minimizing risk to avian species company-wide. In 2013, the Wild
Horse Wind Facility (Wild Horse) Bird and Bat Conservation Strategy (BBCS) was developed to
document agency coordination in the planning, development, and operation of Wild Horse, a
summary of the avian studies completed, and the significant avoidance, minimization, and
mitigation measures implemented to benefit birds and their habitats in the project area. As a
member of the Avian Power Line Interaction Committee (APLIC) since 2004, PSE has participated
in and provided training at workshops annually, contributed to APLIC publications, participated in
APLIC working groups, and coordinated with the Service and others in the industry to stay up -to-
date with best practices and lessons learned, regulatory and permit changes, research, and
issues and concerns related to avian protection.
In April 2013, the Service issued its revised Eagle Conservation Plan Guidance and on
December 9, 2013, the Service published a final rule that provided an eagle take permit for up to
30 years; however the 30-year rule was challenged in court and in August 2015 was reversed. As
a result of the court’s decision, the Service could grant eagle take permits with a maximum tenure
of five years. In 2016, the Service revised the rule to allow for permit terms up to 30 years, and
made additional changes to incorporate the results of the Service’s Eagle Status Report (USFWS
2016) and to add clarity to the eagle permit regulations, improve their implementation, and
increase compliance while maintaining strong protection for eagles.
PSE has developed this draft Eagle Conservation Plan (ECP), incorporating relevant portions of
the PSE corporate APP and Wild Horse BBCS. This ECP documents PSE’s voluntary adherence
to the Eagle Conservation Plan Guidance developed under the Bald and Golden Eagle Protection
Act by the Service to reduce potential adverse effects on bald and golden eagles. This ECP is
consistent with PSE’s company-wide APP, and was developed in consultation with the Service.
This ECP was developed to support PSE’s request for coverage under an incidental eagle take
permit. The conservation measures, predicted level of take, and compensatory mitigation
described in this document are consistent with the goal of maintaining stable or increasing
breeding populations at both the eagle management unit and local population scales. This ECP
describes the actions taken and measures implemented during project development,
construction, and operation to avoid, minimize, and mitigate potential adverse effects on eagles
and their habitats at PSE’s Wild Horse Wind Facility, consistent with permit conditions and best
management practices listed in the Washington State Energy Facility Site Evaluation Council
(EFSEC) Site Certification Agreement (SCA) and the Kittitas County Development Agreement.
The measures summarized in this ECP are also consistent with PSE’s Special Purpose Utility
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(SPUT) Permit for migratory bird monitoring and salvage, issued by the USFWS Regional
Migratory Bird Permit Office (appendix B).
2.0 Project Background and Description
Wild Horse is a 273 MW wind generation facility in eastern Kittitas County, Washington (figures 1
and 2) located on 11,000 acres of open rangeland and shrub-steppe habitat near Whiskey Dick
Mountain. A total of 149 wind turbine generators (WTGs) are mostly located on land owned by
PSE; however some turbines are on public land administered by the Washington Department of
Fish and Wildlife (WDFW) and the Washington Department of Natural Resources (WDNR).Of the
149 total WTGs, 127 are Vestas V80 1.8 MW, and the remaining 22 are Vestas V80 2.0 MW
WTGS. All 149 WTGs are three-bladed wind turbines on steel towers with a height of 351 feet,
with a rotor diameter of 80 m, a hub height of 67 m, and a cut-in speed of 4 m per second.
PSE acquired the original Wild Horse project from Zilkha Renewable Energy (Zilkha) during the
development stage. Zilkha, the project developer, was responsible for obtaining final permits and
constructing the project. PSE took over facility management when Wild Horse became
commercially operational in December 2006. Construction of the original project, consisting of
127 turbines, began mid-October 2005 and was completed in December 2006 when it became
operational.
In early 2009, EFSEC amended the SCA authorizing PSE to expand Wild Horse by an additional
22 turbines. PSE was responsible for permits and construction of the expansion. Construction
began in May 2009 and was completed in November 2009. The expansion began operation on
November 9, 2009.
The entire Wild Horse facility consists of:
127 Vestas V80 1.8-megawatt wind turbine generators (original project).
22 Vestas V80 2.0-megawatt wind turbine generators (expansion).
Approximately 38 miles of new or improved roads.
Approximately 100 miles of underground 34.5-kilovolt (kV) electrical distribution and fiber
optic lines.
Less than 1 mile of 34.5 kV avian-safe overhead electrical power lines.
Approximately 8 miles of 230 kV overhead electrical transmission feeder line.
One on-site electrical step-up substation.
One off-site interconnection substation.
Two permanent un-guyed lattice meteorological towers
A 150-by-75-foot maintenance facility (11,250 square feet).
A Renewable Energy Center (REC) building of approximately 5,000 square feet housing
a visitor information center.
A 450-kW solar demonstration facility site containing 18 arrays of photovoltaic panels
located on 4.5 acres at the former Quarry #1 site, and A 50-kW solar demonstration facility
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site containing 3 arrays of photovoltaic panels located on 0.5 acres adjacent to the REC
for a total solar footprint of 5 acres (of 11,000 total acres).
Overhead and underground connections from the 450 kW and 50 kW solar sites to the
wind facility’s electrical collection and transmission system.
Figure 1. General location of the Facility.
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Figure 2. Map of the Project Facilities.
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2.1 Environmental Setting
The primary habitat in the project area is shrub-steppe, consistent with the typical vegetation zone
of much of the Columbia Basin ecoregion; grasslands are also found on very steep slopes and
exposed ridges (figure 3). This upland habitat type is dominated by big sagebrush, and stiff
sagebrush, with some areas where threetip sagebrush, antelope bitterbrush, and squaw current
are dominant. A mix of grasses and forbs make up the understory. Lithosols are common in this
habitat type, especially on exposed ridgetops. On some steep slopes, fingers of exposed cobbles
and rock are intermingled among herbaceous habitat.
A small amount of riparian habitat is associated with the larger creeks. Native trees and shrubs,
such as Douglas hawthorn and chokecherry, dominate the riparian areas. A small amount of
ponderosa pine forest occurs in a narrow strip along one of the main project area drainages. Wild
Horse is located at the southeastern tip of mountainous/higher elevation region that tapers to the
southeast toward the Columbia River (figure 4). Elevations are highest in the northwest portion of
the project and decrease to the southeast.
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Figure 3. Habitat map / land use of original Wild Horse Project Area (top panel) and the expansion
area corridors (lower panel).
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Figure 4. Digital elevation map
2.2 Initial Consultation
2.2.1 Agency Coordination
The original Wild Horse project was developed, permitted, and constructed by Zilkha and
purchased by PSE. PSE assumed management when the facility commenced commercial
operations in 2006. Zilkha began consultation with state and federal agencies in early 2 003 and
continued throughout the development of Wild Horse as part of the permitting effort to address its
potential effects on federal- and state-listed species, migratory birds, and their habitats (table 2-
1). These activities were consistent with the WDFW Wind Power Guidelines (WDFW, 2003),
which were the accepted recommendations from the Service and WDFW at the time of planning
and development. Under Washington State law, EFSEC is responsible for siting and licensing the
construction and operation of major energy facilities in Washington State. Under the Washington
State Environmental Policy Act (SEPA), EFSEC is the state lead agency for facilities seeking
state site certification. As part of the EFSEC process, WDFW was responsible for identifying
agency issues and concerns regarding potential effects on vegetation, wetlands, wildlife, and
threatened and endangered species within the project area, as well as to solicit guidance on
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protocols for baseline wildlife studies and mitigation measures. EFSEC is comprised largely of
State agency representatives, including WDFW who is responsible as a voting member for
affirming consistency with WDFW guidance.
A summary of agency consultation and coordination, including details and dates of meetings and
correspondence prior to EFSEC’s issuance of the SCA, is contained in section 2.11 of EFSEC’s
draft environmental impact statement (EIS) developed pursuant to SEPA (EFSEC, 2004). In May,
2005 EFSEC’s Final EIS (FEIS) was issued to supplement the Draft EIS (DEIS) with an updated
summary of the project, a list of alternatives, and copies of written comments and public hearing
testimony (EFSEC, 2005). A Supplemental EIS was completed prior to the development of the
expansion. A summary of PSE’s consultation with the wild life resource agencies since the
acquisition of Wild Horse is provided in table 2-1.
2.2.2 Technical Advisory Committee
As a permit condition, EFSEC and Kittitas County required that a Technical Advisory Committee
(TAC) be convened to provide guidance and oversight of the Wild Horse wildlife and habitat
monitoring studies. The TAC was established in 2006 upon the commencement of commercial
operations to evaluate the Wild Horse mitigation and monitoring programs and to determine the
need for further studies or mitigation measures. The Wild Horse TAC is comprised of
representatives from the Service, WDFW, the Washington Department of Natural Resources
(DNR), the Kittitas Audubon Society, the Kittitas County Field and Stream Club, Washington State
University Extension, PSE, and other local interest groups. The TAC provides a neutral forum in
which independent and informed parties can collaborate with PSE in considering operational
monitoring data. The TAC can make advisory recommendations to the EFSEC if the TAC
determines that additional studies or mitigation are warranted to address significant issues that
were not foreseen, or that exceed the projected effects of the Wild Horse facility.
Table 2-1. History of avian/wildlife-related agency coordination since Wild Horse commenced
operations
Date Agency Wildlife Agency
Attendees
Type of
Communication Purpose
8/1/2006 USFWS &
WDFW
Gregg Kurz (USFWS)
Ted Clausing, Edd
Bracken, & Brent
Renfrow (WDFW)
TAC Meeting Reviewed draft avian and bat monitoring
protocols and timing of study.
10/11/2006 USFWS &
WDFW
Gregg Kurz (USFWS)
Brent Renfrow (WDFW) TAC Meeting
Provided an update re: incidental avian
fatalities. Reviewed TAC comments and
approved the avian and bat monitoring plan.
Reviewed post-construction habitat restoration
progress.
5/31/2007 USFWS &
WDFW
Gregg Kurz (USFWS),
Brent Renfrow (WDFW) TAC Meeting
Discussed avian perch deterrents and
reviewed avian monitoring quarterly report.
Reviewed draft grazing management plan.
Toured post-construction restoration progress.
10/25/2007 USFWS &
WDFW
Gregg Kurz (USFWS),
Brent Renfrow, William TAC Meeting
Reviewed avian monitoring quarterly report
and discussed 2nd year avian monitoring plan.
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Table 2-1. History of avian/wildlife-related agency coordination since Wild Horse commenced operations
Date Agency Wildlife Agency
Attendees
Type of
Communication Purpose
Moore, & Edd Bracken
(WDFW)
Reviewed methods, benefits, and
effectiveness of prevent/minimize raptor
perching on transmission lines.
2/19/2008 USFWS &
WDFW
Gregg Kurz (USFWS),
Brent Renfrow, Brock
Applegate (WDFW)
TAC Meeting
Reviewed 2007 avian & bat monitoring results
and discussed options for timing of 2nd year
avian/bat monitoring.
5/16/2008 USFWS &
WDFW
Gregg Kurz, Phil Land
(USFWS), Brent
Renfrow, Brock
Applegate, Edd
Bracken, Jeff Tayer, &
Ted Clausing (WDFW)
PSE provided an update on cheatgrass
management, habitat restoration monitoring,
and 1st quarter results of the Wildlife Incident
Reporting and Handling System (WIRHS)
5/28/2008 USFWS &
WDFW
Gregg Kurz (USFWS),
Brent Renfrow, Brock
Applegate, & Edd
Bracken (WDFW)
TAC Meeting
Discussed plans for Wild Horse expansion,
reviewed results of post-construction raptor
nest survey, aerial sage-grouse surveys, and
other wildlife observations. Discussed effects
of perch deterrents on raptors and corvids and
their use of transmission structures
(benefits/cost/ risk/effectiveness). Discussed
temporary grazing plan for 2008.
7/9/2008 USFWS &
WDFW
Gregg Kurz, Phil Land
(USFWS) Brent
Renfrow,
Brock Applegate,
Edd Bracken, &
Ted Clausing (WDFW)
Email PSE provided the 1st year post-construction
monitoring report.
10/31/2008 USFWS &
WDFW
Gregg Kurz, Phil Land
(USFWS) Brent
Renfrow,
Brock Applegate, Mike
Sprecher, Anthony
Novack, Jeff Tayer,
Edd Bracken,
Ted Clausing, & Travis
Nelson (WDFW)
PSE provided an update on grazing,
cheatgrass/weed management, hunting, and
2008 results from WIHRS.
11/14/2008 USFWS &
WDFW
Gregg Kurz (USFWS),
Brent Renfrow, Brock
Applegate (WDFW)
TAC Meeting
Discussed raptor perch deterrents, reviewed
1st year habitat restoration monitoring results.
Approved timing for 2nd year avian/bat
monitoring. Discussed habitat mitigation
parcel.
2/4/2009 USFWS &
WDFW
Gregg Kurz, Phil Land
(USFWS), Brent
Renfrow, Brock
Applegate, Jeff Tayer,
Email PSE provided 4th quarter results from 2008
WIHRS.
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Table 2-1. History of avian/wildlife-related agency coordination since Wild Horse commenced operations
Date Agency Wildlife Agency
Attendees
Type of
Communication Purpose
Ted Clausing, & Travis
Nelson (WDFW)
2/4/2009 USFWS &
WDFW
Gregg Kurz, Phil Land
(USFWS), Brent
Renfrow, Brock
Applegate, Jeff Tayer,
Ted Clausing, & Travis
Nelson (WDFW)
Email Addendum to the post-construction site
restoration plan for the expansion area.
2/17/2009 USFWS &
WDFW
Gregg Kurz (USFWS),
Brent Renfrow (WDFW)
TAC conference
call
Reviewed post-construction habitat restoration
plan for the expansion area.
6/8/2009 USFWS &
WDFW
Gregg Kurz, Phil Land
(USFWS), Brent
Renfrow, Brock
Applegate, Jeff Tayer,
Ted Clausing, & Travis
Nelson (WDFW)
Email (E-
Newsletter(
PSE provided annual update on TAC/ wildlife
related activities at Wild Horse.
10/7/2009 USFWS &
WDFW
Gregg Kurz (USFWS),
Brent Renfrow, Jeff
Tayer, & Travis Nelson
(WDFW)
TAC Meeting
Reviewed raptor perch monitoring results, 2nd
year habitat restoration monitoring, history of
WDFW’s role in the development of Wild
Horse & conservation efforts, and 2nd year
avian/bat monitoring protocols.
10/21/2009 WDFW Brent Renfrow (WDFW) Memorandum
Summary of comments from 5/15/09 WDFW
site visit during construction of expansion
area.
11/9/2009 USFWS &
WDFW
Gregg Kurz (USFWS) &
Brent Renfrow (WDFW)
TAC conference
call
Reviewed & approved 2nd year avian/bat
monitoring protocols.
1/12/2010 USFWS &
WDFW
Gregg Kurz (USFWS),
Brent Renfrow, Ted
Clausing, & Mike
Schroeder (WDFW)
Meeting
Determined feasibility and options for
additional sage-grouse surveys along the
transmission line corridor related to the
possible installation of raptor perch deterrents.
2/1/2010 WDFW
Mike Schroeder, Mike
Atamian, Mike
Livingston, & William
Moore (WDFW)
Site Assessment
On-the-ground assessment of the habitat
along the transmission line corridor to evaluate
the suitability for sage-grouse and determine
whether additional perch deterrents should be
installed on the transmission pole structures,
or if additional studies were warranted.
5/27/2010 WDFW Shana Winegart
(WDFW)
TAC conference
call
Reviewed & approved the 2010 grazing
management plan.
6/17/2010 USFWS &
WDFW
Greg Kurz (USFWS)
Mike Schroeder, Brent
Renfrow, & Travis
Nelson (WDFW)
Memorandum to
the TAC
Recommendations from USFWS and WDFW
to implement alternative sage-grouse
conservation measures on-site that would
provide more benefit to sage-grouse in lieu of
installing additional perch deterrents on the
transmission pole structures.
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Table 2-1. History of avian/wildlife-related agency coordination since Wild Horse commenced operations
Date Agency Wildlife Agency
Attendees
Type of
Communication Purpose
7/15/2010 USFWS &
WDFW
Gregg Kurz (USFWS),
Brent Renfrow, Travis
Nelson (WDFW)
TAC Meeting
Reviewed WDFW sage-grouse habitat
assessment and joint recommendation
regarding raptor perch deterrents and
alternative sage-grouse conservation
measures. PSE provided an update on the
2010 avian/bat monitoring study. Reviewed 3rd
year habitat restoration monitoring and
conducted field tour to observe restoration
progress.
9/17/2010 USFWS &
WDFW
Gregg Kurz, Phil Land
(USFWS), & Brent
Renfrow, Jeff Tayer, Ted
Clausing, Travis Nelson,
& Mike Schroeder
(WDFW)
PSE provided an update on the
implementation of the alternative sage-grouse
conservation measures.
11/17/2010 USFWS &
WDFW
Gregg Kurz, Phil Land
(USFWS), & Brent
Renfrow, Jeff Tayer, Ted
Clausing, Travis Nelson,
Shana Winegart, Mike
Schroeder, Mike
Livingston, & Anthony
Novack (WDFW)
E-newsletter PSE provided annual update on TAC/wildlife-
related activities at Wild Horse.
5/10/2011 USFWS &
WDFW
Gregg Kurz (USFWS), &
Brent Renfrow (WDW) TAC Meeting
Reviewed implementation of sage-grouse
conservation measures, 2010 grazing
management plan, results of 2nd year
avian/bat monitoring. Discussed timing of 2nd
year avian/bat monitoring for the expansion
area. Toured sage-grouse habitat restoration
area.
8/9/2011 USFWS &
WDFW
Gregg Kurz (USFWS), &
Brent Renfrow (WDFW)
TAC conference
call
Reviewed & approved the avian/bat
monitoring protocols for the expansion area.
4/10/2012 USFWS &
WDFW
Gregg Kurz (USFWS),
Brent Renfrow, Jeff
Tayer, Ted Clausing, &
Travis Nelson (WDFW)
E-newsletter PSE provided update on TAC/wildlife-related
activities at Wild Horse.
10/10/2012 WDFW
Brent Renfrow, Jeff
Burnham, & Mike Ritter
(WDFW)
TAC Meeting
Reviewed results of 5th year habitat restoration
monitoring, reviewed implementation of 2012
grazing management plan.
6/4/2013 USFWS &
WDFW
Gregg Kurz (USFWS),
Brent Renfrow, Mike
Ritter (WDFW)
TAC Meeting
Reviewed 2nd year avian/bat monitoring results
for the expansion area, reviewed alternate
sage-grouse conservation measures.
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Table 2-1. History of avian/wildlife-related agency coordination since Wild Horse commenced operations
Date Agency Wildlife Agency
Attendees
Type of
Communication Purpose
3/10/2014 USFWS
Corky Roberts and
Stephen Lewis
(USFWS)
Meeting
Discussed the development of an ECP and
potential for applying for an eagle permit,
provided information about PSE Avian
Protection Program, provided the revised APP
and Bird and Bat Conservation Strategies.
6/19/2014 USFWS &
WDFW
Corky Roberts (USFWS)
Justin Allegro (WDFW) Phone Notification of golden eagle fatalities on 6/19.
6/20/2014 USFWS RMBPO Email Notification of golden eagle fatalities on 6/19.
6/23/2014 USFWS Corky Roberts Meeting On-site meeting with OLE, visited the fatality
location, transferred eagles.
7/17/2014 USFWS &
WDFW
Stephen Lewis
(USFWS), Brent
Renfrow, Justin Allegro
(WDFW)
TAC Meeting
Discussed the eagle incident, toured the sage-
grouse nesting and brood-rearing habitat
restoration area.
7/31/2014 USFWS &
WDFW
Gregg Kurz, Stephen
Lewis (USFWS), Brent
Renfrow, Mike
Livingston, Mike Ritter,
Mike Schroeder
(WDFW)
Email PSE provided the 2013 WDFW Washington
Golden Eagle Nest Report.
2/12/2015 USFWS &
WDFW
Stephen Lewis
(USFWS), Brent
Renfrow, Mike Ritter,
Justin Allegro (WDFW)
Conference call
TAC meeting to discuss ECP and eagle
fatality monitoring/use survey protocol, and
provide Eagle Permit update
4/9/2015 USFWS Corky Roberts, Manisa
Kung (OLE) Phone Notification of golden eagle fatality on 4/8
4/9/2015 USFWS Jennifer Miller (RMBPO) Email Notification of golden eagle fatality on 4/8
4/10/2015 USFWS Corky Roberts, Manisa
Kung (OLE) In person
Site visit, discussed fatality, transferred the
eagle to OLE.
4/10/2015 WDFW Justin Allegro Phone Notification of golden eagle fatality on 4/8
4/13/2015 USFWS Stephen Lewis Phone Notification of golden eagle fatality on 4/8
9/26/2016 USFWS Manisa Kung (OLE) Phone Notification of golden eagle fatality on 9/26
9/28/2016 USFWS Jennifer Miller (RMBPO) Email Notification of golden eagle fatality on 9/26
WDFW Justin Allegro Phone/email
Notification of golden eagle fatality on 9/26
(left message on v.m. and followed up with
email.
10/3/2016 USFWS Matt Stuber, Stephen
Lewis Phone
Notification of golden eagle fatality on 9/26
during bi-weekly ECP check in call
10/13/2016 USFWS &
WDFW
Stephen Lewis
(USFWS), Brent
Renfrow, Mike
Livingston, Mike Ritter,
Justin Allegro (WDFW)
TAC email notification of golden eagle fatality
on 9/26 and provided eagle use and fatality
monitoring report
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Table 2-1. History of avian/wildlife-related agency coordination since Wild Horse commenced operations
Date Agency Wildlife Agency
Attendees
Type of
Communication Purpose
10/14/2016 EFSEC EFSEC Staff/Council Email Notification of golden eagle fatality on 9/26 in
regular monthly email update to EFSEC.
11/15/2016 EFSEC EFSEC Council In person
Detailed update on golden eagle fatality on
9/26 during monthly EFSEC meeting in
Olympia.
5/31/2017 USFWS &
WDFW
Stephen Lewis
(USFWS)
Brent Renfrow, Mike
Ritter (WDFW)
In person
TAC meeting to provide an update on the
ECP, discuss Sage-grouse habitat restoration
and monitoring, the hunting program, and
grazing management program.
The TAC meets at least once per year during operational monitoring, and will convene for the life
of the project unless one of the following occurs.
The TAC determines that all of the operational monitoring has been completed and further
monitoring is not necessary.
TAC members recommend to the EFSEC that the TAC be terminated.
The TAC ceases to meet due to member attrition.
If the TAC is terminated or dissolved, EFSEC may reconvene and reconstitute the TAC at its
discretion. The role of the TAC is defined in the SCA as follows:
The purpose of the Technical Advisory Committee (TAC) is to ensure that
monitoring data is considered in a forum in which independent and informed
parties can collaborate with the Certificate Holder, and make recommendations to
EFSEC if the TAC deems additional studies or mitigation are warranted to address
impacts that were either not foreseen in the Application or the Environmental
Impact Statement, or exceed impacts that were projected. In order to make
advisory recommendations to EFSEC, the TAC will review and consider: results of
Project monitoring studies, including post-construction avian and bat mortality
surveys. To evaluate impacts to habitat and wildlife, including avian and bat
species; new scientific findings made at wind generation facilities with respect to
the impacts on habitat and wildlife, as they may relate to the Wild Horse Wind
Power Project; assess whether the post-construction restoration and mitigation
and monitoring programs for wildlife that have been identified and implemented
merit further studies or additional mitigation, taking into consideration factors such
as the species involved, the nature of the impact, monitoring trends, and new
scientific findings.
As table 2-1 indicates, the TAC has met regularly since 2006, before Wild Horse commenced
operations, and the Service is a voting member. PSE continues to provide updates to the TAC
throughout the development of this ECP and subsequent coordination with the Service. The role
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of the TAC as it relates to adaptive management is described in more detail in section 6.7 of this
ECP.
As noted in table 2-1, additional consultation occurred in response to golden eagle fatalities
discovered at Wild Horse. On June 18, 2014 Vestas technicians discovered the remains of an
immature golden eagle near turbine F2 in the original project area. On June 19, PSE discovered
the remains of a second immature golden eagle nearby while conducting a site visit. The two
eagles were salvaged and data was collected including condition of the eagles, apparent cause
of mortality, identification information, specific location and proximity to structure, conditions
(temperature, weather, time of day) at the time of discovery, and disposition. PSE notified USFWS
OLE and RMBPO in accordance with the SPUT permit, and met with OLE to conduct an additional
site visit and transfer the two eagles. PSE also notified TAC representatives from WDFW, the
Service, and EFSEC. Information about the two eagle fatalities was presented to the entire TAC
at the annual meeting on July 17, 2014. A third immature golden eagle fatality was discovered
near turbine O2 in the original project area on April 8, 2015 during eagle fatality monitoring studies.
PSE followed similar procedures to the previous incident, and met with USFWS OLE on April 10
to conduct a site visit and transfer the eagle remains. PSE provided notification to USFWS OLE
and RMBPO within 48 hours, and notified the Service, WDFW, and EFSEC TAC members within
five days of discovery. A fourth immature golden eagle was identified incidentally by Vestas
technicians during regular turbine maintenance on September 26, 2016. The remains were found
approximately 90 feet from Turbine N4 in the original project area. Again, similar response and
notification procedures were followed as described in table 2-1.
3.0 Regulatory Framework
3.1 Migratory Bird Treaty Act
The federal regulatory framework for protecting eagles includes the Migratory Bird Treaty Act
(MBTA) of 1918 and the Bald and Golden Eagle Protection Act (BGEPA) of 1940. The MBTA is
the foundation of migratory bird conservation and protection in the United States. The MBTA
implements four treaties that provide for international protection of migratory birds, and is a strict
liability statute, meaning that proof of intent, knowledge, or negligence is not an element of an
MBTA violation. The MBTA protects migratory birds and prohibits the taking, killing, possession,
transportation, import and export of migratory birds, their eggs, parts, and nests, except when y
authorized by the Service. 16 U.S.C.§ 703. Under the MBTA, “take” is defined as “to pursue, hunt,
shoot, wound, kill, trap, capture, or collect, or attempt to pursue, hunt, shoot, wound, kill, trap,
capture, or collect.” 50 CFR § 10.12. The FWS maintains a list of all species protected by the
MBTA at 50 CFR § 10.13. This list includes over one thousand species of migratory birds,
including eagles and other raptors, waterfowl, shorebirds, seabirds, wading birds, and passerines.
The Service has promulgated take regulations for permits for direct take such as hunting and
scientific research, but does not have a permit for incidental take of migratory birds associated
with otherwise lawful activities, such as commercial or industrial operations. However, an eagle
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take permit for bald or golden eagles issued by the Service pursuant to BGEPA serves as
authorization under the MBTA. 50 CFR § 22.11(b).
PSE maintains a Special Purpose Utility (SPUT) Permit under the MBTA for migratory bird
salvage, temporary possession, and monitoring at its wind facilities, administered by the USFWS
Regional Migratory Bird Permit Office (RMBPO) under 50 CFR Part 13 and 50 CFR 21.27
(appendix B).
3.2 Bald and Golden Eagle Protection Act
Under authority of the Bald and Golden Eagle Protection Act (BGEPA), 16 U.S.C. 668–668d, bald
eagles and golden eagles are afforded additional legal protection. BGEPA prohibits the take, sale,
purchase, barter, offer of sale, purchase, or barter, transport, export or import, at any time or in
any manner of any bald or golden eagle, alive or dead, or any part, nest, or egg thereof. BGEPA
goes on to define take as to include “pursue, shoot, shoot at, poison, wound, kill, capture, trap,
collect, molest, or disturb,” and includes criminal and civil penalties for violating the statute. The
Service further defined the term “disturb” to mean to agita te or bother a bald or golden eagle to a
degree that causes, or is likely to cause, based on the best scientific information available: 1)
injury to an eagle; 2) a decrease in its productivity, by substantially interfering with normal
breeding, feeding, or sheltering behavior; or 3) nest abandonment, by substantially interfering with
normal breeding, feeding, or sheltering behavior.
On September 11, 2009 (Federal Register, 50 Code of Federal Regulations [CFR] 22.26 and
22.27), the Service set in place rules establishing two new permit types: 1) individual permits that
can be authorized in limited instances of disturbance and in certain situations where other forms
of take may occur, such as human or eagle health and safety; and 2) programmatic permits that
may authorize incidental take that occurs over a longer period of time or across a larger area. On
December 8, 2013, the Service published in the Federal Register a final rule to extend the
maximum term for an eagle take permit to 30 years, subject to a recurring mandatory 5-year
review process throughout the term of the permit. However, in 2015 the U.S. District Court for the
Northern District of California set aside the Service’s final 30 -year rule on NEPA grounds. In
September 2015, PSE received a letter from the Service stating that until the Service completes
the appropriate NEPA analysis, the maximum term for programmatic eagle take permits is five
years. In December 2016, the Service published revisions to the Rule pertaining to a number of
aspects of the eagle permitting process, including raising the maximum permit term to 30 years,
revising the definition of “preservation standard,” changing the size/scope of the Local Area
Populations and Eagle Management Units for consistency with biological data from the 2016
report (USFWS 2016), addition of monitoring protocols, and changes to compensatory mitigation
requirements and options. PSE is applying for an incidental eagle take permit under the 2016
rule, so the applicable changes have been incorporated in this ECP.
To facilitate issuance of eagle take permits for wind energy facilities, the Service revised the ECP
Guidance in 2013. If eagle mortalities are identified as a potential risk at a project site, developers
are strongly encouraged to follow the ECP Guidance, which describes specific actions that are
recommended to achieve compliance with the regulatory requirements in BGEPA for an eagle
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take permit. The ECP Guidance provides a national framework for assessing and mitigating risk
specific to eagles through development of ECPs and issuance of eagle take permits for wind
facilities.
The ECP Guidance document was written to guide development of wind energy projects from
their earliest conceptual planning phase and recognized that it may not be possible for projects
already in the development or operational phase to implement all stages of the recommended
approach. The ECP Guidance notes that projects “in operation prior to 2009 that pose a risk to
golden eagles may qualify for incidental eagle take permits that do not automatically require
compensatory mitigation because the requirements for obtaining incidental take authorization are
designed to reduce take from historic baseline levels, and the preamble to the Eagle Permit Rule
specified that “unavoidable take remaining after implementation of avoidance and minimization
measures at such projects would not be subtracted from regional take thresholds.”
Wild Horse is an operational facility that was developed in two phases. The original project
commenced operation in 2007, prior to the promulgation of the eagle permit rule and finalization
of the ECP Guidance, and therefore falls into this category of project. The expansion, which
includes 22 additional turbines, commenced operation in November 2009, following promulgation
of the eagle permit rule. PSE has been communicating with the Service regarding impacts of Wild
Horse on eagles and developed this ECP in coordination with the Service to document avoidance
and minimization measures undertaken by PSE to reduce the potential impacts on eagles, and
mitigation measures already taken or proposed to compensate for any remaining practicably
unavoidable impacts. This ECP is intended to support PSE’s application for an incidental eagle
take permit.
3.3 National Environmental Protection Act
The National Environmental Policy Act (NEPA) [42 U.S.C. 4321 et seq.] establishes national
environmental policy and goals for the protection, maintenance, and enhancement of the
environment and provides a process for implementing these goals within the federal agencies.
NEPA ensures that potential environmental impacts of federal actions and appropriate mitigations
for those impacts are fully considered through a systematic interdisciplinary approach. All federal
agencies are required to prepare detailed statements assessing the environmental impact of, and
alternatives to, major federal actions that significantly affect the environment. Issuance of an
incidental eagle take permit by the Service constitutes a federal action and thus requires an
assessment of the potential environmental impacts associated with the action and alternatives
under the NEPA. Because the Service issued a final PEIS concurrent with its 2016 eagle rule,
incorporation or tiering to the analysis in the PEIS should provide efficiencies for individual
projects to adhere to NEPA. The Service will continue to comply with NEPA for incidental eagle
take permits for individual projects.
3.4 PSE’s Corporate Environmental Policy
Puget Sound Energy employees at all levels will comply with all environmental laws, regulations,
and Company environmental policies. The company encourages environmentally responsible and
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sustainable behavior, and holds Company employees accountable for environmental
performance.
PSE encourages this behavior, and holds Company employees accountable for environmental
practices as follows:
We comply with all applicable environmental laws and regulations.
We provide sufficient resources to maintain environmental compliance with laws and
regulations.
We ensure that regular and independent reviews of environmental aspects of our business
are conducted.
All levels of management are responsible for the following:
Integrating appropriate environmental management into business practices,
Understanding environmental compliance requirements associated with their job
functions; and
Committing to bring environmental compliance issues and concerns forward for resolution.
4.0 STAGE 1 – PRELIMINARY ASSESSMENT
Zilkha began planning and development of Wild Horse in 2002. One full year of wildlife and
ecological baseline studies were conducted from May 10, 2002 through May 22, 2003 to
characterize the wildlife and habitats in the project area, and to estimate the potential effect of the
construction and operation of Wild Horse. A comprehensive environmental review of the proposed
project was completed in accordance with SEPA. In August 2004, an EIS (EFSEC, 2004) was
issued by EFSEC, the lead agency responsible for permitting Wild Horse. The EIS determined
that with mitigation, the facility was not anticipated to have any significant unavoidable adverse
effects on birds or other wildlife. In July 2005, the EFSEC authorized the construction and
operation of Wild Horse in accordance with the terms and conditions set forth in the Site
Certification Agreement, or SCA (EFSEC, 2005). In November 2008, a supplemental EIS
(EFSEC, 2008) was prepared for the expansion of Wild Horse. The EFSEC amended the SCA in
January 2009 to allow construction and operation of an additional 22 wind tu rbines in the
expansion area.
The project site was selected primarily for its strong winds and its proximity to high voltage
transmission lines of adequate capacity to integrate the wind-generated power with the power
grid. Another attractive feature for site selection was the road system, which required minimal
construction of new roads for project access.
A list of state- and federally-protected species potentially present within the project area was
compiled to assess the facility’s potential for affecting these species. Species were identified
based on the WDFW species of concern list, which includes state-listed endangered, threatened,
sensitive, and candidate species; and the Service’s central Washington Ecological Services Office
list of endangered, threatened, proposed, candidate, and species of concern for Kittitas County.
Information about occurrence of these species in the project area was based largely on:
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Habitat mapping and predicted distribution from the Washington State Gap Analysis
Program (GAP) project.
WDFW Priority Habitats and Species (PHS) records for the project area and a buffer of
approximately 5 miles (8 km).
Location data and predicted distributions from the Breeding Bird Atlas of Washington State
(Smith et al., 1997).
5.0 STAGE 2 SITE-SPECIFIC SURVEYS AND ASSESSMENTS
This section documents the quantitative and qualitative scientific studies conducted at Wild Horse
prior to construction in order to assess the potential risk to birds and their habitats. The studies
quantify the distribution, relative abundance, behavior, and site use of species of concern. The
results of these studies were used to design and operate Wild Horse to avoid, minimize, and
mitigate any significant adverse effects and to determine the duration and level of post -
construction monitoring.
5.1 Raptor Nest Surveys
Aerial raptor nest surveys were completed for both the original Wild Horse project area (WEST,
2003) and the expansion (WEST, 2007) to locate raptor nests that may be subject to disturbance
or displacement effects from the construction and operation of Wild Horse. Surveys were
scheduled just prior to the onset of leaf-out to increase the visibility of raptor nests within
deciduous forest habitats, and after most species of raptor finished courtship and were incubating
eggs or brooding young. Nest searches were conducted in habitat suitable for most above -ground
nesting species, such as cottonwood, ponderosa pine, tall shrubs, and cliffs or rocky outcrops.
5.1.1 Methods
Raptor nest surveys were conducted within the project area and a 2-mile buffer, an area totaling
approximately 49 mi² (127 km²). Surveys were conducted from a helicopter with one observer on
April 14, 2003, and surveys were conducted for the expansion on April 7, 2006 (figure 5). Search
paths were recorded with a handheld Global Positioning System (GPS) at five second intervals.
In addition to raptor nests, observations of big game were recorded, and searches for sage-
grouse (leks and flushed birds) were also conducted. Flight paths totaled 290 miles (467 km) in
length. The helicopter was flown at an altitude of tree top level to approximately 250 feet (76 m)
above the ground during surveys. If a nest was observed, the helicopter was moved to a position
where nest status and species present could be determined. Efforts were made to minimize
disturbance to breeding raptors, including keeping the helicopter at a maximum distance from the
nest at which the species could be identified. Those distances varied depending on the nest
location and wind conditions. Data recorded for each nest location included species occupying
the nest, nest status (inactive, bird incubating, young present, eggs present, adult present,
unknown, or other), nest substrate (tree species, shrub, rocky outcrop, cliff, or power line
structure), number of young present, time and date of observation, and the GPS location.
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5.1.2 Results
During the pre-construction raptor nest surveys conducted within the 2-mile buffer, one inactive
nest was located in an area described as a historical golden eagle nest territory within the northern
portion of the search area in April 2003. No active golden eagle nests were found during surveys
conducted in 2003 or 2006. No bald eagle nests were identified during either survey. Non -eagle
raptor nests are shown in figure 5, and are presented in more detail in the Wild Horse Raptor Nest
Survey Reports (WEST 2003; 2007) and the Wild Horse Bird and Bat Conservation Strategy.
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Figure 5. Raptor nest surveys (flight paths) conducted in 2003 (upper panel) and 2006 (lower
panel) in the vicinity of Wild Horse.
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5.2 Bird Use Surveys
Diurnal fixed-point avian use surveys were conducted at Wild Horse from May 10, 2002 through
May 22, 2003 (Erickson et al. 2003)1. The goal of the avian use surveys was to estimate the
temporal and spatial use of the study area by birds. The avian use surveys combined observations
collected at seven fixed-point circular plots in the study area with in-transit observations of birds
made while driving to and from the study area. All observations of wildlife species of concern and
uncommon species were recorded while the observers were in the study area traveling between
observation points and while conducting other field activities.
5.2.1 Methods
Each plot consisted of a 2,625 foot (800 m) radius circle centered on an observation point.
Landmarks were located to aid in identifying the 2,625-foot boundary of each observation point.
Observations of birds beyond the 2,625-foot radius were recorded, but these observations were
not included in standardized use estimates.
All detections of birds, mammals, reptiles, and amphibians in and near plots during the 30-minute
plot surveys were recorded. Visual and binocular scanning of the entire plot viewshed and beyond
were continuously performed throughout the survey period. A unique observation number was
assigned to each sighting. The following data were recorded for each plot survey: date, start and
end time of observation period, plot ID, species or best possible identification, number of
individuals, sex and age class when known, distance from plot center when first observed, closest
distance, first, lowest, and highest altitude above ground, flight direction, behavior(s), habitat(s),
whether observed during one or more of the three instantaneous counts, and in which of the two
ten-minute periods it was observed. The first flight height recorded was used to estimate
percentages of birds flying below, within, and above the rotor swept area (RSA). The zone of
collision risk used was 25-100 m above ground level (AGL). Flight paths were mapped for raptors
and species of concern and given corresponding observation numbers. The map of eagle flight
paths and survey stations (figure 6) indicates whether the bird was within or outside the survey
radius based on reference points at known distances from the plot center. Flight paths were
digitized, and climate information, such as temperature, wind speed, wind direction, precipitation,
and cloud cover were also recorded for each point count survey.
Surveys were typically conducted on weekly intervals during the spring, early summer and fall,
and occasionally during the winter months. In total, there were 103.5 hours of survey effort spread
throughout the year (15 hours in spring 2002, 39.5 hours in fall 2002, 7 hours in winter 2002/2003,
31.5 hours in spring 2003, and 10.5 hours in summer 2003). During a set of surveys, each
selected plot was visited once. A pre-established schedule was developed prior to field work to
ensure that each station was surveyed about the same number of times each period of the day,
1 Bird use surveys were conducted between May 2002 and May of 2003, with the exception of summer surveys. An additional 10.5
hours of surveys were conducted during summer 2003 that were not included in Erickson et al. (2003). Methods for these surveys
were the same as those presented in Erickson et al. (2003).
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during each season, and to most efficiently utilize personnel time. The schedule was altered in
response to adverse weather conditions, which required delays and/or rescheduling of surveys.
Species lists were generated by season including all observations of birds detected regardless of
their distance from the observer. The number of birds seen during each point count survey was
standardized to a unit area and unit time surveyed. The standardized unit time was 30 minutes
and the standardized unit area was a 2,625-foot radius plot. For the standardized avian use
estimates, only observations of birds detected within 2,625 feet of the observer were used.
Estimates of avian use (expressed in terms of the number of birds/plot/30-minute survey) were
used to compare differences in avian use between 1) avian groups and 2) seasons.
Figure 6. Map of bird use survey points and eagle flight paths
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5.2.2 Golden Eagle Results
A total of 179 30-minute fixed-point count surveys were conducted from May 10, 2002 through
summer 2003. Mean avian use estimates were calculated by species and season, and grouped
by bird size due to differences in the detectability of small and large birds. Seasons were defined
as spring (mid-March to mid-June), summer (mid-June to mid-September), fall (mid-September
to mid-December), and winter (mid-December to mid-March). Exact start and stop dates for each
season depended on when a survey round of all points was completed. Golden eagle use was
estimated to be 0.035/800m plot/30-minute survey during spring/summer, 0.143 during the fall,
and 0.082 during the winter, with an overall annual use estimate of 0.075.
Frequency of occurrence measures how often a species was observed during 30-minute point-
count surveys (% of surveys) and was calculated as the percent of surveys in which a particular
species was observed. Golden eagles were observed during roughly 14% of fall surveys, 8% of
winter surveys, and 3% of spring/summer surveys. Golden eagle observations included three
observations of three separate groups in the spring/summer, seven observations of seven
separate groups in the fall, and five observations of five separate groups in the winter. Thirteen
of the 15 golden eagle observations were recorded within the 800-m survey plots at heights of
200 m or less. Minute by minute data were not recorded for individual observations; therefore, for
the purpose of modeling fatalities, each observation was equated to one minute of observation
time (see Section 8.3), which is consistent with the Service’s ECP Guidance (USFWS, 2013).
Roughly half of the 15 golden eagle observations were recorded within the rotor swept area (table
5-1). A total of two golden eagles in two separate groups were observed incidentally during transit
between survey stations. Both incidental observations were recorded during the winter season
(late November 2002 and January 2003).
Although no active nests were identified during surveys, golden eagles were documented during
fixed-point surveys throughout the year. Golden eagles have nested historically within two miles
of the project area, so these historical nests were considered during project siting. Details on nest
locations are provided in section 8.2.1 of this plan. Overall use of the project area was determined
to be relatively low compared to other wind facilities where golden eagle mortalities have been
documented. While the potential exists for golden eagles to collide with turbines, based on
baseline surveys and information available at the time, overall risk to golden eagle populations
was considered low and only a few individuals were predicted to collide with the turbines over the
life of the project.
5.2.3 Bald Eagle Results
Only one bald eagle was observed during the winter. No bald eagles were observed during
spring/summer or fall surveys. Mean use for bald eagles was 0.020 during the winter surveys,
with an annual use estimate of 0.005 eagles/800-m plot/30-min survey. The only bald eagle
observation recorded was within the rotor swept height of turbines (table 5 -1). No bald eagles
were observed during the raptor nest surveys. Based on the apparent low use of the project area
by bald eagles, impacts to the species were considered to be negligible.
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Based on available information about bald eagle use of the site, if bald eagle mortality occurred
due to the operation of the facility it would likely be confined to winter and early spring seasons.
Bald eagles are not expected to frequently occur within the project area, and operation of the
facility is likely to cause minimal disturbance to bald eagles. Although risk to bald eagles is low,
the potential exists for bald eagle mortalities during the operation of the project.
Table 5-1. Flight height characteristics for eagle observations recorded during surveys
conducted from May 2002 to May 2003 at Wild Horse.
Collision Risk Height (25-100m AGL)
% Below % Within % Above
Bald eagle 0.0 100.0 0.0
Golden eagle 30.8 53.8 15.4
5.3 Summary of Eagle Use
During baseline avian use surveys, golden eagles were among the most frequently observed
raptor species, following American kestrels and red-tailed hawks. A total of 15 individuals were
observed during pre-construction surveys, and two were incidentally observed while surveyors
were in transit. Only one bald eagle was observed during baseline avian use surveys. The majority
of golden eagle observations occurred in fall and winter, while the one bald eagle was also
detected in winter. Raptor use in general was relatively low in spring/summer compared to the fall
and winter periods.
Table 5-2. Number of eagle observations recorded by season2 during surveys conducted from May 2002 to May 2003 at Wild Horse.
Incidental Spring/Summer Fall Winter Total
Number of
Surveys 86 47 46 179
Bald eagle 0 0 0 1 1
Golden
eagle 2 3 7 5 17
In addition, no active bald or golden eagle nests were identified during pre -construction raptor
nest surveys conducted in 2003 for the original project area or 2006 for the expansion. One nest
was located in April 2003 in an area described as a historical golden eagle nest territory, but there
was no indication that the nest was occupied or active in 2003.
2 Seasons were defined as spring: mid-March to mid-June, summer: mid-June to mid-September, fall: mid-September to mid-
December, and winter: mid-December to mid-March.
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Based on pre-construction avian use surveys and raptor nest surveys, bald eagle use of the site
was low, with no obvious concentration areas in the project area. Overall use of the project area
by golden eagles was relatively low compared to other wind facilities where golden eagle fatalities
have been publicly reported. There were no apparent golden eagle concentration areas in the
project area (Erickson et al. 2003).
6.0 STAGE 4 AVOIDANCE AND MINIMIZATION OF RISK –
CONSERVATION AND MITIGATION MEASURES
Conservation measures were developed in several stages, beginning during the initial planning,
design, and permitting stages, and continuing through construction and operation for the life of
the project. Many measures have the potential to benefit birds and other wildlife, while some have
specific benefits to eagles, consistent with the ECP Guidance. These measures are described in
the sections below.
During the design of Wild Horse, Zilkha, the original project developer, incorporated numerous
features to avoid or minimize the facility’s potential effects on protected migratory birds, including
eagles, in addition to other wildlife and their habitats. These features were based on site surveys,
experience at other wind power projects, and recommendations from wildlife agencies and
consultants performing studies at the site.
6.1 Conservation Measures benefitting eagles and other protected migratory birds
6.1.1 Pre-construction
The following list of conservation measures were implemented during the pre-construction phase
of Wild Horse, and are consistent with the ECP Guidance.
Locating turbines no less than 150 meters from springs identified during habitat mapping.
Locating turbines away from riparian areas that likely contain a higher diversity of bird
species.
Locating turbines approximately 140 meters from the area known as The Pines, in the
central portion of the project area.
Locating turbines away from prominent saddles along the main Whiskey Dick Ridge.*
Minimizing new road construction where feasible by improving and using existing roads
and trails instead of constructing new roads.
Placing electrical collection lines underground wherever feasible to minimize perching
locations and electrocution hazards to birds.
Using low-RPM turbines and tubular towers to minimize the risk of avian collision with
turbine blades and perching on towers.
Installing bird flight diverters on guyed temporary meteorological towers, and using un -
guyed permanent meteorological towers, to minimize the potential for avian collision with
guy wires.
Building power poles consistent with APLIC recommendations to minimize the risk of avian
electrocution.
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Installed approximately 100 miles of underground 34.5 kV electrical distribution lines and
fiber optic lines to minimize the risk of avian collisions and electrocutions.
6.1.2 Consultation and siting of turbines
During the preliminary site evaluation of the original project area between 2002 and 2006, Zilkha,
the original project owner/developer made significant efforts to avoid areas considered to be
sensitive habitat for sage-grouse. Several turbines were initially proposed for the northwest
portion of the project area. The collision risks associated with these turbines were similar to those
for most of the turbines within the project area; however, the northwest portion of the project area
has historically been used by sage-grouse. The proposal for the string of turbines in this area was
dropped, increasing the amount of land unoccupied by wind turbines within the project area and
creating additional movement corridors for sage-grouse and other wildlife while also reducing the
collision risk for eagles. Another nine turbines were eliminated from the original project layout to
comply with Federal Aviation Administration height restrictions, further minimizing eagle collision
risk along the ridgeline of Whiskey Dick Mountain.
In 2009, during development of the expansion, PSE significantly modified the preliminary
turbine layout for the expansion area in direct response to WDFW recommendations
during the environmental review process. Four proposed wind turbines, associated roads,
and electrical collector lines were omitted from the project in the planning stage to address
the WDFW’s concerns. These turbines would have been located adjacent to an important
wildlife area, and together with the supporting infrastructure they had the potential to affect
sensitive wildlife that use the area. Removing these turbines from the project design during
the planning stages provided benefits to eagles by eliminating the risk for collision with
those turbines and the associated overhead transmission line.
6.1.3 During Construction
The EFSEC SCA and the Kittitas County Development Agreement list the following conditions
that were implemented during construction of Wild Horse to reduce the risk to eagles, other birds,
and their habitats during construction (EFSEC, 2005). The first six measures are consistent with
the ECP Guidance. The remaining three measures provide additional benefit to wildlife and their
habitats in general.
Avoidance of construction in sensitive areas such as streams, riparian zones, wetlands,
and forested areas.
Flagging of any sensitive habitat areas (e.g., springs, raptor nests, wetlands) near
proposed areas of construction activity and designation of such areas as “off limits” to all
construction personnel.
Establishment and enforcement of reasonable driving speed limits (max 25 mph) during
construction to minimize potential for road kills and eagle-vehicle collisions.
Required construction personnel to avoid driving over or otherwise disturbing areas
outside the designated construction areas.
Designation of an environmental monitor during construction to monitor construction
activities and ensure compliance with mitigation measures.
Removal of temporary guyed meteorological towers.
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Development and implementation of a fire control plan, in coordination with local fire
districts, to minimize risk of accidental fire during construction and respond effectively to
any fire that does occur.
Use of certified “weed free” straw bales during construction to avoid introduction of noxious
or invasive weeds.
Reseeded all temporarily disturbed areas cleared of vegetation during construction with
an appropriate mix of native plant species, selected in consultation with WDFW, to
accelerate the restoration of these areas and to prevent the spread of weeds.
6.1.4 During Operation
PSE assumed ownership of Wild Horse upon commencement of operations, and began
implementing operational conservation measures at that time. Several of the measures
implemented provide direct benefits to eagles, such as establishing and enforcing a 25-mile-an-
hour speed limit on roads in the project area to reduce the risk of road kills and eagle collisions
with vehicles. In addition, PSE has implemented a carcass removal program on site, in
coordination with hunters, to reduce the potential for attracting eagles to the project area. Hunter
harvest cards distributed by PSE have been updated to include information about removing gut
piles from the project area and using non-lead shot to help minimize the risk of lead poisoning to
eagles.
PSE ensures compliance with the following operations-related permit conditions as described in
the Site Certification Agreement (EFSEC, 2005) to reduce the risk to wildlife species of concern
and their habitats during project operations. The first four measures are consistent with the ECP
Guidance, and provide direct benefit to eagles that may be using the project area. The remaining
measures provide additional benefit to wildlife and their habitats in general.
Establishment and enforcement of reasonable driving speed limits (max 25 mph) to
minimize potential for avian/vehicle collisions and road kills that may attract eagles or other
raptors.
Identification and removal of all carcasses of livestock, big game, etc. from within the
project area that may attract foraging eagles or other raptors.
Restoration of springs throughout the project area including wildlife escape ramps to
prevent drowning and installation of temporary fencing to exclude cattle but allow access
for wildlife.
Control public access to the site to minimize disturbance impacts on wildlife, especially in
winter months.
Implementation of a fire control plan, in coordination with local fire districts, to avoid
accidental wildfires or respond effectively to any that might occur.
Implementation of an effective noxious weed control program, in coordination with the
Kittitas County Noxious Weed Control Board, to manage the spread of and prevent the
introduction of noxious weeds.
Livestock grazing was not allowed until after a post-construction rangeland management
plan was developed and implemented in coordination with the TAC and WDFW in
particular. The plan addresses management strategies intended to improve residual grass
cover and potential nesting, brood-rearing, and habitat for sage-grouse and other shrub-
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steppe nesting species. The plan includes provisions for the restoration of shrub -steppe
lands, native seeding prescriptions, and management of livestock grazing on shrub-
steppe rangelands. Livestock grazing at the springs has been eliminated. If fences are
needed to protect these springs, they are constructed using fence designs conducive to
passage by wildlife and shall be maintained for the life of the project.
As stated in the SCA, during sage-grouse lekking season, no routine maintenance of the
substation area or facilities shall be conducted within ¼ mile of an active lek between the
hours of sunset and 9:00 a.m., and recreational use of the project area will be restricted
to the extent feasible (EFSEC 2005). To date, no active leks have been identified in the
project area.
6.2 Additional Conservation Measures
These additional measures were implemented as conditions of the EFSEC SCA and Kittitas
County Development Agreement for the construction and operation of Wild Horse.
Construction activities will be avoided, to the greatest extent possible, outside areas that
will be permanently disturbed except during the months of May through October when soil
moisture is low.
Use of BMPs to minimize construction-related surface water runoff and soil erosion.
Proper storage and management of all wastes generated during construction.
Operational BMPs to minimize storm water runoff and soil erosion.
6.3 Wildlife Incident Reporting and Handling System Procedures
PSE developed and implemented procedures for responding to birds and bats that are found
incidentally within the project area as required by the SCA, and consistent PSE’s SPUT permit.
These procedures, developed in coordination with the TAC, are outlined in the Wildlife Incident
Reporting and Handling System Manual (WIRHS). The purpose of the WIRHS is to standardize
and describe the actions taken by Wild Horse site personnel in response to wildlife incidents found
within the project boundary (figure 14). The WIRHS procedures were implemented when project
operations began and will be in place for the life of the project, independent of any formal avian
and bat monitoring studies. PSE provides training annually and additionally as needed for on -site
personnel regarding the importance and proper procedures of reporting eagle and other avian
and wildlife incidents in the project area in accordance with the WIRHS and the SPUT permit
requirements. This training includes identification of avian and bat carcasses found incidentally
when conducting monthly turbine inspections.
If an avian or bat carcass is found, specific actions are followed as described in the WIRHS
manual in response to the incident. On-site field personnel procedures include notifying PSE staff,
noting the location and condition of the bird or bat, searching the immediate area, not disturbing
the find, and completing a field report if PSE staff can’t be contacted. Once PSE is notified of a
bird or bat incident, additional actions are taken as soon as possible, including taking photos and
a GPS location, completing a respondent form, filling out an index card to place with the bird or
bat, and securing the bird or bat and placing in the freezer on-site. Data collected to fill out the
respondent form is consistent with data requested by FWS RMBPO as directed by PSE’s SPUT
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permit. PSE staff will record as much data as possible, such as date and time of discovery,
weather conditions, species, condition of the bird/bat, apparent cause of injury/mortality,
estimated time since death/injury, field marks, nearby structure, distance and direction from
structure, location remarks, disposition if the bird/bat, and any additional field notes.
If an eagle carcass is found on site, the on-site Environmental Manager is immediately notified,
who then contacts PSE’s avian protection program biologist(s). The avian biologist(s) conduct a
site visit, examine the carcass, and follow the instructions of FWS OLE, consistent with the
conditions of the SPUT permit. Eagle carcasses are either transferred to the FWS Law
Enforcement Officer, or are sent directly to the FWS Eagle Repository per the instructions of OLE.
In accordance with PSE’s Avian Protection Plan reporting procedures and SPUT reporting
conditions, all dead and injured birds found at Wild Horse are reported to State and Federal
Wildlife Agencies as described in the SPUT permit, and consistent with the SCA. PSE personnel
and contractors will follow procedures outlined in the WIRHS when responding to dead or injured
birds that are found incidentally in the project area. Any incident involving a state- or federally-
listed threatened or endangered species or a bald or golden eagle will be reported to the FWS
and WDFW within 24 hours of identification, or the next business day if found on a weekend or
holiday. All incidentally found MBTA-protected species and bats are reported annually to the FWS
Regional Migratory Bird Permit Office.
6.4 Conservation measures and sage-grouse
Several conservation measures were implemented to benefit sage-grouse, a state-threatened
species. These measures were developed in consultation with the Service, WDFW and the TAC,
and are consistent with the Washington State Sage-grouse Recovery Plan. These measures are
also consistent with the COT objectives, and include:
Implementing a fire control plan
Invasive weed management
Protecting sage brush, restoring temporarily disturbed areas, minimizing development of
new roads
Avoid constructing turbines and other project-related facilities in high quality habitat areas
Implementing a grazing management plan to minimize the effects of grazing in the project
area
Removed unnecessary fencing, marked remaining fences to minimize the risk of collisions
Manage recreation within the project area
6.5 Mitigation under the Site Certification Agreement
A settlement agreement between PSE and the WDFW for Wild Horse was executed in 2005
(WDFW, 2005) in which the WDFW stipulated that compliance with the terms of the agreement
would mitigate impacts to fish and wildlife resources, including habitats, to a level of non-
significance under the WDFW Wind Energy Guidelines (WDFW 2003). Effects to eagles under
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BGEPA and level of significance for the purpose of this ECP are discussed in section 8.7, and
are evaluated in more detail in the EA.
PSE mitigated all permanent and temporary disturbances to native vegetation caused by the
construction and operation of Wild Horse in accordance with the shrub-steppe habitat
replacement ratios outlined in the WDFW Wind Power Guidelines (WDFW, 2003) for siting and
mitigating wind power projects in Washington. PSE followed the WDFW Guidelines as
recommended by the Service, which were the available guidelines at that time.
Mitigation at the original Wild Horse project area includes legal protection of 600 acres of high -
quality shrub-steppe habitat located within the project boundary. The 600-acre parcel is located
within the project boundary, and consists of all of Section 27, T8N, R21E with the exception of a
40-acre corridor containing 12 wind turbines running north to south. Protected for the life of the
project and fenced to eliminate livestock grazing, this area preserves a diversity of native habitats
including a segment of Whiskey Dick Creek, and provides continuity with privately-owned wildlife
habitat and adjacent state-owned lands. In addition, two parcels totaling 120 acres were conveyed
to WDFW by PSE as mitigation for the expansion (figure 2). These mitigation parcels were
selected in consultation with the WDFW and meet the requirements for mitigation ratios outlined
in the WDFW Wind Power Guidelines (2003).
6.6 Conservation Easement
PSE signed a voluntary conservation agreement with the WDFW in December 2008 to preserve
and protect the conservation value of 7,500 acres owned by PSE at Wild Horse. Located within
the largest block of remaining shrub-steppe habitat in Washington, this conservation area is
surrounded by state-owned wildlife areas, providing connectivity for wildlife and protecting
important shrub-steppe habitat, springs, creeks, and riparian areas in perpetuity.
6.7 Adaptive Management under the EIS
This section describes the adaptive management approach as defined in EFSEC’s DEIS and
FEIS under SEPA as part of wildlife mitigation. It is a similar, but separate process from adaptive
management as defined by the ECP Guidance (section 11.0). An adaptive management approach
allows the TAC to review monitoring results and the best available science to determine whether
the current monitoring and mitigation efforts are effective and efficient. The SCA states that the
TAC will “assess whether the post-construction restoration, mitigation, and monitoring programs
for wildlife that have been identified and implemented merit further studies or additional mitigation,
taking into consideration factors such as the species involved, the nature of the impact, monitoring
trends, and new scientific findings.” Adaptive management, as described in section 3.5.4.4 of the
DEIS, is a process to be used by the TAC to address issues or circumstances that typically either
were not foreseen in the EIS or that significantly exceed the predicted conditions that arise during
project operation. If the TAC identifies more effective alternative measures, the TAC can make
recommendations for approval by the EFSEC.
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7.0 STAGE 5 POST-CONSTRUCTION MONITORING
The purpose of post-construction monitoring is to quantify the effects of project operations on
eagles, other avian species, and bats, compare actual mortality estimates to predicted mortality
estimates, and assess the adequacy of the mitigation measures implemented. At Wild Horse,
fatality monitoring has occurred over four time periods. The first three years of monitoring (2007,
2010, and 2012) were focused on birds and bats in general and are described in Section 7.1-
Standard Post-Construction Fatality Monitoring. The fourth year of monitoring, described in
Section 7.2 – Formal Eagle Fatality Monitoring, occurred in 2015-2016 and was specifically
focused on documenting eagle fatalities at Wild Horse. There are three scenarios under which
mortalities may be found: 1) during the standardized searches for the study; 2) while observers
are on site but not conducting a standardized search; and 3) by wind facility personnel or others
on site for other purposes such as turbine maintenance. The reporting and handling methods for
wind facility personnel are addressed by the Wildlife Incident Reporting and Handling System
described in further detail in section 9.3 of this plan.
7.1 Standard Post-Construction Fatality Monitoring
The primary objective of post-construction fatality monitoring is to estimate bird and bat mortality
attributable to collision with project wind turbines during the study period. Standard post -
construction fatality monitoring studies conducted at Wild Horse were broken into three survey
periods: 1) January to December 2007 encompassing the original project area, 2) March to
December 2010 encompassing both the original project and the expansion, and 3) March to
December 2012 for the expansion (Erickson et al., 2008; Enz et al. 2011, 2013)
7.1.1 Methods
The methods are broken into four primary components: standardized carcass surveys of selected
turbines; searcher efficiency trials to estimate the percentage of carcasses found by searchers;
carcass removal trials to estimate the length of time that a carcass remains in the field for possible
detection; and statistical analysis used to estimate the annual bird and bat mortality.
7.1.2 Standardized Carcass Surveys
There are two un-guyed permanent meteorological towers in the original project area, and none
in the expansion area, so no met towers were searched as part of the monitoring effort in the
project area. Turbines were selected for sampling using a constrained random design. Search
plots were rectangular in shape and extended a minimum of 110 m (361 ft) fr om the nearest
turbine in the plot (figure 7). When initially set up for the Wild Horse fatality monitoring, plot sizes
were based on data from other studies at facilities with large turbines that indicated most
carcasses are found within the area that is roughly equivalent to the height of the turbine tower
(Jonson et al. 2003, Young et al. 2005, Kerlinger et al. 2007). Hull and Muir (2010) found that
95% of large bird fatalities fell within 110 m of turbines at the study sites they reviewed. They went
on to recommend that a survey area radius of 112 to 122 m would capture 95% of the large bird
fatalities at medium and large modern turbines, respectively (Hull and Muir 2010). Based on the
search plot design at Wild Horse, the minimum distance to plot edge was 110 m, with distances
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to the plot corners being 155 m, which based on the turbine sizes at the Project was sufficient to
capture a high percentage (greater than 95%) of all fatalities which may have occurred during the
study period (Hull and Muir 2010).
Figure 7. Illustration of standard search plot and transects.
During the 2007 monitoring for the original project, standardized carcass surveys were conducted
within 32 plots, each consisting of two turbines, for a total of 64 search turbines for the year (figure
8a). Standardized searches were conducted on a 28-day search interval. During spring and fall
migration periods the search effort was increased at a subset of the selected plots (8 plots; 16
turbines) to once a week (i.e., a seven-day search interval). For post-construction fatality
monitoring, seasons were defined as follows: spring (March 16-June 15), summer (June 16-
September 15, fall (September 16-December 15, winter December 16-March 15).
During the 2010 monitoring, standardized searches were conducted within 28 plots, each
consisting of two turbines for a total of 56 search turbines (Figure 8b). Of the 56 turbines, 12 were
searched in the expansion and 44 were searched in the original project. One turbine in the original
project area was searched in 2007 and again in 2010. Standardized searches of all plots were
conducted on a 14-day search interval throughout the nine month monitoring period. For the entire
monitoring period, 1,063 turbine searches were conducted with over 3,600 hours of searching.
In 2012, standardized carcass searches were conducted on six plots in the expansion, four of
which consisted of two turbines, and two plots consisting of one turbine each, for a total of 10
search turbines (Figure 8c). After the 2010 survey, the TAC requested that turbines U1 and U2
be searched a second year. Otherwise, turbines searched during the 2010 monitoring year were
not included in the 2012 turbine sample. Searches were conducted on a 14-day search interval
for nine consecutive months (March 15 to December 13).
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Standardized carcass searches were conducted by biologists trained in proper search techniques.
Searchers systematically walked parallel transects while scanning both sides of the transect for
bird and bat carcasses. Transects were spaced approximately six to eight m (20 to 26 ft) apart
and were established to allow 100% coverage of each search plot.
Searchers assigned all carcasses a unique number, and completed a data sheet recording
species, sex and age when possible, date and time collected, GPS location, carcass condition,
and cause of mortality. The location of the carcass was plotted on a detailed map of the study
area showing the nearest wind turbine; photographs were taken of the carcass as found in the
field. Once the data was recorded, each carcass was bagged with a freezer tag and stored in an
on-site freezer for reference and possible necropsy. Mortalities found outside of search plots, or
observed within search areas but outside of a formal search, were coded as incidental discoveries
and documented in the same manner.
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Figure 8a. Map of Wild Horse post-construction monitoring turbine search plots for 2007.
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Figure 8b. Map of Wild Horse post-construction monitoring turbine search plots for 2010.
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Figure 8c. Map of Wild Horse expansion post-construction monitoring turbine search plots for
2012.
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Carcass condition was recorded using the following categories:
Intact – a carcass that is completely intact, is not badly decomposed, and shows no sign
of being fed upon by a predator or scavenger.
Scavenged – an entire carcass, which shows signs of being fed upon by a predator or
scavenger or a portion(s) of a carcass in one location, or a carcass that has been heavily
infested by insects.
Feather spot – ten or more feathers or two or more primaries at one location indicating a
bird carcass has been there.
7.1.3 Searcher Efficiency Trials
The objective of the searcher efficiency trials was to determine the percentage of carcasses found
by searchers. Results of these trials were used to adjust the annual mortality estimates for
detection bias. Searcher efficiency trials were conducted simultaneously with carcass searches;
trial results were analyzed to distinguish effects of carcass size and season.
Trial carcasses were randomly placed within search plots by a field supervisor prior to that day’s
scheduled carcass search. Searchers did not know when trials were being conducted or the
location of the searcher efficiency carcasses. Each trial carcass was discreetly marked so that it
could be identified as a trial carcass. The number and location of searcher efficiency carcasses
found by searchers were recorded. The number of carcasses available for detection during each
trial was determined immediately following the trial by the field supervisor.
Trials were conducted throughout the year to incorporate seasonal effects. Carcasses were
placed in all project habitat types to account for variations in visibility under different search
conditions. Two carcass size classes (large and small) were used and were primarily non-
native/non-protected or commercially available species, as well as native bird and bat carcasses
found at Wild Horse during the monitoring effort. The most commonly used avian species were
Coturnix quail (Coturnix coturnix), horned lark (Eremophila alpestris), house sparrow (Passer
domesticus), hen mallard (Anas platyrhynchos), hen ring-necked pheasant (Phasianus
colchicus), and rock pigeon (Columba livia). The quail, horned larks, and house sparrows were
used as small bird surrogates, while the mallard, pheasant, and pigeons were used as large bird
surrogates.
During the 2007 studies, a total of 162 carcasses (82 large, 80 small) were placed in the field
during 10 searcher efficiency trials. Overall searcher efficiency rates in 2007 were 41% for small
birds and 74% for medium-large birds.
During the 2010 studies, a total of 136 bird carcasses (58 small birds, 67 large birds, and 11 bats)
were placed on search plots on 10 separate trial dates. The overall searcher efficiency rate for
small birds in 2010 was 29.0%, while the searcher efficiency rate for large birds was 57.6%.
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For the 2012 study, searcher efficiency trial data were combined with trial data from 2010,
resulting in a total of 213 trial carcasses (106 large birds, 94 small birds, and 13 bats). The overall
searcher efficiency rate for large birds was 61.5%, while the rate for small birds and bats was
33.0%. Because so few bats were available for the searcher efficiency trials, estimates for small
birds and bats were combined.
7.1.4 Carcass Removal Trials
The objective of carcass removal trials was to estimate the average length of time a carcass
remained in the study area and was available for detection. Carcass removal trials were
conducted concurrent with each year of fatality monitoring in 2007, 2010, and 2012 and the results
were used to adjust estimates of annual mortality for removal bias. However, because removal
trials conducted during those time periods utilized surrogate carcasses including rock pigeon, hen
mallard, and hen pheasant, the resulting carcass persistence times are not thought to be
representative of how long an eagle carcass would persist. As such, a raptor -specific removal trial
was conducted in 2016 (section 7.2.4) to estimate carcass persistence, and that data were used
in lieu of the 2007-2012 data to estimate eagle-specific fatality rates in those study years.
7.1.5 Results of Post-construction Bird Fatality Monitoring
No bald or golden eagle carcasses were identified during the 2007, 2010, or 2012 post -
construction fatality monitoring studies as a part of standardized searches or incidentally.
Although no eagle injured eagles or eagle fatalities were documented during the studies, there
were several incidental observations of flying and/or perched eagles recorded during the post -
construction monitoring studies. During the 2007 monitoring studies, there was one bald eagle
observation, and four golden eagle observations in four separate groups. During the 2010
monitoring studies, eight bald eagles were observed in five separate groups in addition to 16
golden eagle observations in 14 separate groups. No bald or golden eagles were incidentally
observed during the 2012 fatality monitoring studies.
7.2 Formal Eagle Fatality Monitoring
To support the issuance of an incidental eagle take permit, PSE implemented one year of eagle-
specific fatality monitoring from March 2015 through March 2016 (WEST 2016). The purpose of
this monitoring was to improve confidence in the fatality prediction and to better understand how
eagles currently may be using the project area spatially and temporally. The formal eagle fatality
monitoring studies incorporated a standardized search protocol, along with searcher efficiency
trials and raptor persistence data to document eagle take related to Wild Horse. Details for the
eagle-specific fatality monitoring studies are provided below, and were reviewed by the TAC and
accepted by the Service prior to implementation.
7.2.1 Visibility/Detection Mapping
Maps were created that included three visibility/detection classes (easy, medium, difficult) for
search plots based on aerial photography, land cover/ habitat mapping, topography, and on -the-
ground verification. Mapping occurred during the initial setup of the plots and search transects.
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7.2.2 Eagle Carcass Searches
Standardized carcass searches for eagles were conducted approximately every 28 days at all
149 turbines. Square search plots measuring 160 meters (m) on a side were established at each
turbine, which, due to turbine spacing created some overlap of search plots (figure 9). All 149
plots were searched with transects spaced approximately 20 m apart.
To help prepare for a long-term operational monitoring approach (section 9.2), a reduced effort
survey protocol was tested prior to conducting each transect-based plot search. The reduced
effort survey consisted of searchers driving to the search turbine while scanning for potential
carcasses in the search plot. The searcher parked the vehicle and walked around the edge of the
turbine pad scanning for eagle carcasses, with the aid of binoculars as needed to confirm potential
carcasses. If a potential carcass was observed, the location of the carcass would be marked on
a map. Once the initial scan was complete, the searcher would collect data on any identified eagle
carcasses. If any carcasses had been found using the initial drive-up and scan method, they
would have been identified as being found with this approach. Non-eagle fatalities were recorded
as incidental findings and managed according to the WIRHS.
After the initial scan and data collection was complete, the searcher began walking transects at
an average rate of approximately 45-60 m per minute, while scanning the area on each side of
the transect line (i.e., ~10 m either side of the line). The rate of the search varied depending on
the visibility at the particular transect.
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Figure 9. Wild Horse search plots for eagle fatality monitoring.
7.2.3 Searcher Efficiency Trials
The objective of the searcher efficiency trials was to estimate the proportion of fatalities that were
found by searchers and were conducted during the course of the eagle-specific fatality monitoring
to estimate the detection rates of searchers. Turkey decoys were placed throughout the project
to be discovered by carcass searchers. The turkey decoys were covered with a harness of real
turkey feathers (Turkey Skinz; Away Hunting Products, Beaverton, Michigan) and have been
identified as a suitable surrogate for large avian carcasses and used at other facilities for similar
efficiency trial purposes. Trial decoys were placed in all visibility classes and in all seasons.
Seventy searcher efficiency trials were conducted throughout the study period. Searchers found
62 of the 70 trials, resulting in a searcher efficiency rate of 89%. Estimated searcher efficiency
was used to adjust the total number of trial carcasses/decoys found for those missed by the
searchers.
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7.2.4 Carcass Removal Trials
At the conclusion of the year-long study period, WEST and PSE were able to obtain the
appropriate permits and a source of raptor carcasses to conduct a carcass removal trial to
estimate the amount of time that eagle carcasses may persist on the landscape and be available
for discovery by searchers. Raptors used in persistence trials were salvaged, handled, and
disposed of consistent with PSE’s SPUT permit and appropriate state permits. A removal trial was
initiated on May 14, 2016, which included 19 raptor carcasses (10 barn owls, 6 red-tailed hawks,
1 great horned owl, 1 long-eared owl, and 1 prairie falcon). The trial carcasses were spread
throughout the project, with no more than one carcass placed at a turbine. Carcasses were placed
in all three visibility classes. Carcasses were checked on days 1, 2, 3, 4, 7, 10, 14, 25, and 34,
and once approximately every seven to 10 days through day 122. As of day 34 (i.e., the first check
that exceeded that fatality search interval), all 19 carcasses were still available; with only two
having deteriorated to the point of being labeled as feather spots (defined as 10 or more feathers
at one location). The other 17 were largely intact aside from variable levels of scavenging. On day
86, 17 of the 19 carcasses were still detectable and on day 122 (end of the trial) nine of the 19
were still detectable.
7.2.5 Results of Formal Eagle Fatality Monitoring
One golden eagle fatality was documented during the 2015-2016 eagle-specific fatality monitoring
study, which was found on April 8, 2015. The carcass was found at Turbine O2 during the first
search of that turbine. The carcass had been scavenged to some degree, making the time since
death difficult to determine. It was therefore assumed that the fatality had occurred within the last
28 days (i.e., within the study search interval) and the fatality was included in estimation of the
annual fatality rate for the study period. No bald eagles were found during the 2015 carcass
searches.
7.3 Post-Construction Raptor Nest Surveys
The objective of the post-construction aerial raptor nest surveys was to locate raptor, corvid, and
other large bird nests that may be subject to disturbance and displacement effects and from which
the occupying birds may be potentially at risk from operation of the wind energy faci lity. Surveys
were conducted from a helicopter on March 25, 2008 and on April 27, 2011. Both surveys included
the original project, the expansion, and a one-mile buffer, with the methods and survey area
approved by the WDFW and the TAC prior to implementation.
7.3.1 Methods
Aerial raptor nest surveys were conducted using methods similar to pre-construction nest surveys
(section 5.1.1).
7.3.2 Results
In 2008, one historic golden eagle nest within the study area was checked for nesting activity. In
addition, all the nests located during the 2003 pre-construction nest survey were checked for
nesting status. A historical golden eagle nest had been previously documented in conifers near
the northwest boundary of the study area; however, no nest was found during the 2008 su rvey. A
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large stick nest had been found in this area during the 2003 pre-construction raptor nest surveys
but was inactive at that time. No bald or golden eagle or sensitive species nests were found in
the expansion area or the one-mile buffer in 2011.
7.4 Fixed-Point Eagle Use Surveys
Fixed-point eagle use surveys were conducted concurrent with formal eagle fatality surveys from
March 2015 through March 2016 to provide updated information useful for estimating the temporal
and spatial use of Wild Horse by eagles and to evaluate current eagle use of the project area
relative to the eagle use recorded during pre-construction surveys. Although data were collected
consistent with ECP Guidance recommendations, the data were not fully incorporated into the
model because they were collected during the operational phase of the project, not prior to turbine
construction.
7.4.1 Methods
Fixed-point surveys were conducted at 12 survey points distributed throughout the project area.
Each point was centered in a survey plot with an 800-m radius. Points were distributed such that
the 800-m radius survey plots included a majority of all project turbines. Surveys consisted of 1-hr
observation periods conducted at each point. Surveys were conducted weekly, with approximately
half the points surveyed each week, resulting in one complete round of surveys every two weeks
and a total of approximately 310 hours of observation effort over the year of surveys.
All eagles observed were recorded regardless of their distance from the survey point; however,
surveyors focused on detecting eagles within the 800-m survey plots. For each survey, the
surveyor recorded the date, start and end time of observation period, plot number, species or best
possible identification, number of individuals, sex and age class if possible, distance from plot
center when first observed, closest distance, height above ground, and activity. Eagle behavior
and habitat were also recorded for each observation. Perch locations and flight paths were
mapped for all eagles observed. Flight height and behavior data were recorded at one-minute
intervals for all eagle observations within the 800-m surveys plots.
7.4.2 Results
Thirteen golden eagle and eight bald eagle observations, along with three observations of
unidentified eagles, were recorded during 310 hours of fixed-point surveys conducted at Wild
Horse between March 2015 and March 2016 (table 7-1). Consistent with pre-construction
surveys, eagle use was relatively low during the study period (<0.01 eagles/plot/60 -min survey
for bald and golden eagles individually). Golden eagles were observed from fall through spring,
but not during summer, while bald eagles were only observed in late winter and early spring (table
7-2). Eagle observations were recorded from 10 of the 12 survey points, with no more than three
observations recorded from any single survey point. Golden eagles were observed within the 800
m survey plots at heights of 200 m or less on three occasions for a total of 12 minutes (table 7 -
3). Bald eagles were observed within the 800 m survey plots at heights of 200 m or less on three
occasions for a total of nine minutes presented in table 7-3 and discussed further in section 8.3.1.
Given the low number of observations spread throughout the project, the data suggest there were
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no concentrated eagle use areas within the project, which was consistent with the results of pre-
construction surveys.
Table 7-1. Summary of eagle observations (obs) recorded during 310 hours of fixed-point eagle use surveys conducted at Wild Horse from March 2015 – March 2016.
Eagle Species # of Eagle
Obs
# of Obs ≤ 800 m
from Observer and
≤ 200 m AGL
Eagle Risk Minutes
golden eagle 13 3 12
bald eagle 8 3 9
unidentified eagle 3 0 0
Total 24 5 21
Table 7-2. Summary of eagle observations (obs) recorded during 310 hours of fixed-point eagle
use surveys conducted at Wild Horse from March 2015 – March 2016.
Species Jan Feb Mar Apr May June July Aug Sept Oct Nov Dec
golden eagle 2 2 0 1 4 0 0 0 0 1 3 0
bald eagle 0 5 1 2 0 0 0 0 0 0 0 0
unidentified
eagle 0 0 1 2 0 0 0 0 0 0 0 0
Hours of
Observation 28 22 26 26 26 30 24 24 25 29 24 26
Table 7-3. Summary of golden eagle results from eagle use surveys conducted from March 2015 through March 2016. Eagle minutes are defined as the total number of minutes golden eagles were observed flying within the 0.5-mi (800-m) radius and below 650 ft (200m) AGL.
Spring 2015
Summer 2015
Fall 2015
Winter 2015/16
Total
Golden Eagle
Survey Hours 84 60 84 82 310
GOEA Observations at All Distances and Heights 5 0 4 4 13
GOEA Observations ≤200m AGL ≤ 800m 1 0 2 0 3
Eagle Minutes ≤200m AGL and ≤800m 7 0 5 0 12
Bald Eagle
Survey Hours 84 60 84 82 310
BAEA Observations at All Distances and Heights 3 0 0 5 8
BAEA Observations ≤200m AGL ≤ 800m 1 0 0 2 3
Eagle Minutes ≤200m AGL and ≤800m 1 0 0 8 9
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8.0 STAGE 3 ASSESSING EAGLE RISK AND PREDICTING FATALITIES
FOR WILD HORSE
The Service uses a three category system in defining risk to eagles in the ECP Guidance, and
their definitions are provided below. The following sections discuss several risk factors for eagles
and the information used to evaluate the risk characterization of PSE’s Wild Horse wind facility,
including evaluating eagle use areas, calculating the fatality estimate, and understanding local-
area population size and cumulative annual take. Based on the data presented in the following
sections, we conclude that Wild Horse meets the criter ia of a Category 2 site.
Category 1 – For sites with high risk to eagles, and potential to avoid and mitigate impacts
is low
A project is in this category if it:
(1) has an important eagle‐use area or migration concentration site within the project footprint; or
(2) has an annual eagle fatality estimate (average number of eagles predicted to be taken
annually) > 5% of the estimated local‐area population size; or
(3) causes the cumulative annual take for the local‐area population to exceed 5% of the estimated
local‐area population size.
Category 2 – High or moderate risk to eagles, opportunity to mitigate impacts
A project is in this category if it:
(1) has an important eagle‐use area or migration concentration site within the project area but not in the project footprint; or
(2) has an annual eagle fatality estimate between 0.03 eagles per year and 5% of the estimated local‐area population size; or
(3) causes cumulative annual take of the local‐area population of less than 5% of the estimated
local‐area population size.
Category 3 – Minimal risk to eagles
A project is in this category if it:
(1) has no important eagle use areas or migration concentration sites within the project area; and
(2) has an eagle fatality rate estimate of less than 0.03 eagles per year; and
(3) causes cumulative annual take of the local‐area population of less than 5% of the estimated
local‐area population size.
Projects in category 3 pose little risk to eagles and may not require or warrant eagle take permits,
but that decision should be made in coordination with the Service.
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8.1 Assessing Eagle Use
8.1.1 Nesting and Breeding
For the purposes of this ECP, the following definitions are intended to apply to the status of eagle
nests. An in-use nest is defined as “a bald or golden eagle nest characterized by the presence of
one or more eggs, dependent young, or adult eagles on the nest in the past 10 days during the
breeding season.” An alternate nest is defined as “one of potentially several nests within a
territory that is not an in-use nest at the current time, (i.e., did not contain eggs, young, or adults
displaying courtship) . Lastly, an occupied territory is a territory for which an in -use nest was
present or there were observations of a breeding pair of adult eagles in the territo ry during the
survey year.
Aerial nest surveys were conducted within a 2-mile buffer of the original phase of Wild Horse in
spring 2003 and within a 2-mile buffer of the Wild Horse expansion in spring 2006 (figure 5).
Although no active eagle nests were identified during either survey effort, it is possible that some
nests could have been occupied earlier in the breeding season and that eggs were never laid.
One inactive stick nest was located in a previously described golden eagle nesting territory during
the 2003 survey, within the northern portion of the 2-mile survey buffer. It should be noted that
nest surveys were only conducted once during each effort (April 2003 and April 2006); therefore
neither effort would be considered to have met current protocols regarding eagle nest occupancy
monitoring (Pagel at al. 2010, USFWS 2013), but were in line with recommended protocols and
had been approved by WDFW at the time they were conducted. No eagle nests were located
during post-construction nest surveys conducted in 2008 and 2011. Additional location data was
obtained from WDFW on eagle nesting territories and is discussed in section 8.2.1 as it pertains
to inter-nest distances.
8.1.2 Concentration Areas (Communal Roosts, Foraging Areas, Migration Corridors, and
Migration Stopovers)
The golden eagle data collected during pre-construction surveys suggested that golden eagles
use Wild Horse throughout the year, although use was slightly greater in the fall and winter
compared to the spring/summer. One bald eagle and 15 golden eagle observations were recorded
during the year of baseline surveys (May 2002-May 2003), in addition to two incidental golden
eagle observations. Combined with the lack of nests within the project footprint, this data suggests
that Wild Horse does not contain any eagle concentration areas (e.g., communal roosts, key
foraging areas). Eagle flight paths recorded during baseline surveys were spread across the
project, with eagles observed at six of seven survey locations during 2002-2003 surveys. Eagles
that were observed primarily showed localized movement patterns, suggesting that they were not
actively migrating. Although eagle use was greatest in the fall (0.14 golden eagles/800-m plot/30-
min survey), the observational data (e.g., birds moving nor th in fall, non-direct flight paths)
recorded during baseline studies showed no indication of a migration corridor through the project
area. Data did indicate that the project area was used by foraging eagles, although foraging was
widely dispersed (i.e., not concentrated in any particular area).
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8.2 Eagle Risk Factors
An assessment of the factors known or thought to be associated with increased probability of
collisions between eagles or other raptors and wind turbines at Wild Horse is provided in table 8-
1. The risk factors and the science behind the risk factors have been adopted from the ECP
Guidance (USFWS 2013). Three main risk factors identified in the ECP Guidance are:
1) bird density,
2) the interaction of topographic features, season, and wind currents to create favorable
conditions for high-risk flight behavior near turbines; and
3) behavior that distracts eagles and presumably makes them less vigilant (e.g., active
foraging or inter- and intra-specific interactions).
Given the very low activity rate observed for bald eagles at Wild Horse, and the general lack
of bald eagle foraging habitat (i.e., no rivers or lakes present) in the project area, this section
focusses on golden eagles, although some risk factors could apply to both species.
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Table 8-1. Qualitative assessment of risk factors listed in the Eagle Conservation Plan Guidance Version 2 (ECPG Table 1, page 15) as
they pertain to the Wild Horse Wind Energy Facility (see also Section 5.2).
Risk Factor Scientific Evidence/Support Citations Project Situation Qualitative Assessment
Bird Density Mixed findings; likely some relationship,
but other factors have overriding influence across a range of species.
Barrios and Rodriguez (2004),
DeLucas et al. (2008), Hunt (2002),
Smallwood et al. (2009), Ferrer et al.
(2011)
Based on site-specific pre-construction survey data, golden eagle use
(abundance) was estimated to be 0.075/800-m plot/30-minute survey,
while bald eagle use was estimated at 0.005/800-m plot/30-min survey,
Low / moderate
Bird Age
Mixed findings. Higher number of fatalities among subadult and adult golden eagles in one area. Higher fatalities among adult white-tailed
eagles in another.
Hunt (2002), Nygard et al. (2010)
Data collected to date suggest a mix of adult and subadult eagles at the
project. Low / uncertain
Proximity to Nests
White‐tailed eagle nesting areas close to turbines have been observed to have low nest success and be abandoned over time.
Nygard et al. (2010) No eagle nests occur within the
project. Closest known territory is about 2 km from the project.
Low / moderate
Bird Residency
Status
Mixed findings. Higher risk to resident adults in Egyptian vultures (Neophron
percnopterus). High number of mortalities among subadults and floating
adults in golden eagles in one other study.
Barrios and Rodriguez (2004),
Hunt (2002)
Pre-construction survey data suggest relatively low use year round, with
more adults than subadults observed, but unknown if use is primarily residents or floaters/migrants.
Low
Season
Mixed findings. In some cases for some species, risk appears higher in seasons
with greater propensity to use slope soaring (fewer thermals) or kiting flight
(windy weather) while hunting.
Barrios and Rodriguez (2004), De Lucas et al. (2008),
Hoover and Morrison (2005), Smallwood et
al. (2009)
Site-specific data suggests eagles appear to use the project more
frequently during the fall and winter than in spring/summer. Most eagle observations were within or below
potential rotor swept height.
Moderate / Uncertain
Flight Style Species most at risk perform more
frequent flights that can be described as kiting, hovering, and diving for prey.
Smallwood et al. (2009)
Eagle observation data at the project documented a prevalence for lower
elevation soaring/flapping flight styles, indicative of slope soaring.
Uncertain
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Table 8-1. Qualitative assessment of risk factors listed in the Eagle Conservation Plan Guidance Version 2 (ECPG Table 1, page 15) as they pertain to the Wild Horse Wind Energy Facility (see also Section 5.2).
Risk Factor Scientific Evidence/Support Citations Project Situation Qualitative Assessment
Interaction with Other
Birds
Higher risk when interactive behavior is occurring.
Smallwood et al. (2009)
Based on the distribution of known nests in the region, there is little reason to suspect territorial defense to occur where turbines are sited (i.e., areas of potential territory overlap are outside
the project.
Low
Active Hunting/Prey Availability
High risk when hunting close to turbines, across a range of species.
Barrios and Rodriguez (2004), De Lucas et al. (2007),
Hoover and Morrison (2005), Hunt (2002),
Smallwood et al. (2009)
Although no specific prey surveys have been conducted, jackrabbits are likely
to be the key prey species in the project area. Eagle behavior recorded
during observations suggests relatively low level flights indicative of tactics used to pursue lagomorphs or other
small mammals (e.g., ground squirrels).
Moderate
Turbine Height
Mixed, contradictory findings across a range of species
Barclay et al. (2007), De Lucas et al.
(2008)
Turbines are of a modern design and sit on 68-m towers, with a rotor radius of 39 m, bringing the maximum turbine height to 107 m from base to blade tip.
Unknown
Rotor Speed
Higher risk associated with higher blade tip speed for golden eagles in one study,
but this finding may not be generally applicable.
Chamberlain et al. (2006)
Turbines exhibit current technology, low RPM’s, and more space between
rotor sweeps relative to older generation turbines; however, the tip
speeds are generally the same.
Low
Rotor-swept Area
Meta-analysis found no effect, but variation among studies clouds
interpretation Barclay et al. (2007)
Turbines are of a modern design with a rotor-swept diameter of 78 m.
Low
Topography
Several studies show higher risk of collisions with turbines on ridge lines
and on slopes. Also a higher risk exists in saddles that present low-energy ridge
crossing points.
Barrios and Rodriguez (2004), De Lucas et al. (2008),
Hoover and Morrison (2005), Smallwood
and Thelander (2004)
Turbines are primarily sited along ridge tops, although most are on gentle
slopes as ridges are relatively wide providing a setback from most steep slopes. A few turbines are situated closer to steep slopes on short side
ridges.
Moderate
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Table 8-1. Qualitative assessment of risk factors listed in the Eagle Conservation Plan Guidance Version 2 (ECPG Table 1, page 15) as they pertain to the Wild Horse Wind Energy Facility (see also Section 5.2).
Risk Factor Scientific Evidence/Support Citations Project Situation Qualitative Assessment
Wind Speed Mixed findings; probably locality
dependent.
Barrios and Rodriguez (2004),
Hoover and Morrison (2005), Smallwood et
al. (2009)
Not likely a large issue at Wild Horse, based on the prevailing wind direction
in relation to topography, including slope, aspect, and elevation.
Low
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8.2.1 Inter-nest Distance Buffer Analysis
The ECP Guidance includes a risk characterization approach that makes use of the average
nearest-neighbor (inter-nest) distance among nests (USFWS 2013). The ECP Guidance suggests
that the project area to be assessed be based on the project footprint plus a buffer equal to the
average inter-nest distance, which the Guidance defines as the project area, as it relates to the
risk of taking eagles (USFWS 2013). One-half of the average inter-nest distance is an estimate
of the potential territorial (i.e., defended) area around each occupied nest (or nest cluster) and
thus the area of greatest activity by breeding adults. Generally, a project with little overlap of this
distance and proposed turbine sites is not considered to be in a high risk category based on the
ECP Guidance (USFWS 2013).
Data on historical eagle nest locations in the vicinity of Wild Horse was obtained from WDFW.
Location data were provided for six golden eagle nests within 10 miles of Wild Horse, along with
one bald eagle nest. The bald eagle nest was 15.25 km (9.5 mi) from the nearest Wild Horse
turbine and the data indicated that the eagle nest tree had blown down in 2006. The six golden
eagle nests ranged from about 2.0 km (1.25 mi) to about 16 km (10 mi) from the nearest Wild
Horse turbines. A map illustrating the general distribution of eagle nests is provided in figure 10
while table 8-2 provides data regarding inter-nest distances for the six golden eagle nest sites. It
should be noted that the inter-nest distances are based on all six locations regardless of
occupancy status, as occupancy data were not provided for all nest areas across years. Based
on the distribution of nests, it is assumed that all could be occupied in a given year; hence all
were included in the calculation of inter-nest distances.
Based on the six historical nest areas provided by WDFW, the average inter -nest distance was
4.97 km (3.09 mi; table 8-2). When the six golden eagle nests were buffered by one half the inter-
nest distance (1.55 mi [2.49 km]), only the closest nest had any overlap with the project footprint,
with the five northernmost turbines (Turbines S1, S2, S3, S4, and R01) falling within the perimeter
of the nest buffer. These five turbines were associated with the Wild Horse expansion and no
additional avian use surveys were required prior to the expansion; thus no pre-construction survey
data is available specific to this portion of the project. Survey point E (see figure 6) was the closest
survey station to the expansion; and only a single eagle observation was recorded at point E while
most other points had multiple eagle detections. During the eagle-specific use surveys conducted
in 2015-2016, there were 2 golden eagle observations recorded from survey point 1, the northern-
most survey point in the project area.
Table 8-2. Inter-nest distances for occupied golden eagle nest sites/breeding areas within 10 miles
of the Wild Horse Wind Energy Facility.
Year Documented Nest ID Nearest Nest ID
Inter-Nest Distance (Miles)
2014 54783 54784 2.83
2013 54784 54783 2.83
2014 54861 130820 2.43
2014 54877 130820 2.69
2014 54878 54877 5.35
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2013 130820 54861 2.43
Mean Internest Distance 3.09 mi Half Internest Distance 1.55 mi
Figure 10. Eagle nests within ten miles of Wild Horse and turbine locations
8.2.2 Topography and Wind
The topography of Wild Horse at a landscape scale is illustrated in figure 12 and appendix A.
Elevations at turbines vary from roughly 800 m (2,624 ft) to about 1100 m (3,600 ft), with the
highest elevations occurring along the northwestern turbine strings and the lowest elevations at
the most southeastern turbines. Based on limited scientific study (Young et al. 2003), it is
assumed turbines on steeper slopes, especially on upwind sides of ridges and turbines in saddles
or low-lying areas, may have increased risk of impacts to eagles. The slope and aspect of turbines
at Wild Horse were reviewed and assessed on an individual basis. Figures 11, 12, and 13 illustrate
the prevailing winds at Wild Horse and show the project layout relative to slope and aspect.
Turbines are generally located along ridge tops, with most (63%) located on relatively gentle
slopes of five degrees or less, while 39 are located on more moderate slopes of between five and
10 degrees. Sixteen turbines (11%) are located on steeper slopes of (11-22 degrees). Generally,
none of the turbines are located in low-lying areas or in saddles, while relatively few are located
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on steep slopes (only seven on slopes of 15 degrees or more). About 40% of the turbines have a
southeast aspect (from 91-180 degrees), while the remaining 60% are about equally distributed
among southwest (181-270 degrees), northwest (271-360 degrees), and northeast (1-90
degrees) aspects. Appendix A contains the estimated slope and aspect associated with each
turbine.
A rose diagram (figure 11) depicts the prominent wind direction at Wild Horse, which is primarily
out of the west, with a smaller secondary component from the northeast. Turbines at Wild Horse
are located primarily along prominent and secondary ridges, separated by distinct drainages.
Most of the turbine strings are oriented in a north-south or northwest-southeast direction;
therefore, prevailing winds (from the west) are generally perpendicular to many turbine strings,
potentially creating updrafts along the western flank of turbine strings located on the north-south
ridges. This is most noticeable along turbine strings A, B, C, D, and R (figure 12); although in
combination with slope, it would appear that string A, portions of string C, and the southern two
thirds of string D would have the greatest potential for significant updrafts due to the combination
of steep slopes and prevailing winds (figure 12). The secondary wind component, from the
northeast, likely influences risk at turbine strings located on the more minor side ridges than along
the major north-south ridges. As seen in figure 13, turbines with north-northeasterly aspects are
scattered throughout the area; however, when looked at in combination with the steeper slopes,
the northern ends of strings F, G, and H appear to have increased potential for creating strong
updrafts that may attract eagles. Other areas where slope and aspect combine to increase updraft
potential for northeasterly winds would be along the southern end of string C, and near turbines
J2, U1, and T2 (Figures 12 and 13). Pre-construction avian use surveys indicated some eagle
use along the western flank of turbine string D, in the area from roughly D8 through D14; however
use in this area was not substantially different from that of other survey points.
Based on the information provided, most turbines would not be considered high risk as they are
located on relatively gentle slopes and relatively wide ridges and are typically set back to some
extent from steeper slopes. This helps to minimize risk to eagles using updrafts along the
windward sides of ridges. The results of the landscape-scale assessment of topography and wind,
as well as the individual turbine assessment, suggest that elevated risk to golden eagles would
likely be restricted to a few areas (see Figure 12), which would vary depending on wind direction.
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Figure 11. Rose diagram of prominent wind at the Wild Horse Wind Energy Facility.
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Figure 12. Slope calculations for the Wild Horse Wind Energy Facility. Red outlines indicate areas
where slope and aspect, in association with prevailing winds, may create relatively more consistent updrafts and improved flight conditions for soaring eagles. Green outlines areas where slope and aspect, in association with secondary/northeasterly winds, may create updrafts and improved flight conditions for soaring eagles.
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Figure 13. Aspect of the Wild Horse Wind Energy Facility.
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8.2.3 Intra-Specific Interactions
Based on an estimated nesting territory size of one-half the mean inter-nest distance, one eagle
territory located to the northwest of the project has some overlap with turbines in the far northwest
portion of the project. A second potential eagle territory is located about 4.5 km (2.8 mi) to the
southwest of this nest, creating some overlap of these adjacent territories, however the area of
overlap is located roughly 1.0 to 3.0 km (0.6 to 1.9 mi) west of the nearest turbines. Although the
spatial distribution of these nests doesn’t create any territory overlap (i.e. , areas of potential
conflict) within the project, there is some potential for eagles to interact with one another when
foraging in the vicinity of the project. It is assumed that this would occur more often outside the
breeding season and the potential for significant interactions would be less than if the eagles were
defending a territory during the breeding season. Given the lack of eagle nests/territories in the
project footprint, and the distribution of those in the surrounding area, the potential for intra-
specific interactions believed to increase collision risk (e.g., territory defense) is likely to be
minimal among locally breeding resident eagles. However, there is greater potential for interaction
between resident eagles and floating/non-resident eagles in the northwestern portion of the
project, especially if the nesting territories to the west and northwest of the project are occupied
(see Figure 10).
8.2.4 Adult Versus Juvenile and Resident Versus Floater/Migrant
Eight of the 15 golden eagle observations recorded during pre-construction fixed-point bird use
surveys were of adult eagles, while four were recorded as subadults, and the remaining three as
unknown age. Of the two golden eagles observed incidentally, one was an adult while the other
was of unknown age. The one bald eagle observed during pre-construction surveys was an adult.
Fourteen of the 17 total golden eagle observations and the one bald eagle observation were
recorded during the fall and winter periods, while only three golden eagles were recorded in the
spring or summer.
During the 2015 eagle use surveys, a total of 13 golden eagle observations (3 adults, 8 subadults,
and 2 of unknown age) were recorded. These observations occurred during all seasons except
summer, with the greatest number of observations (five) occurring during the spring, followed by
fall and winter (four observations each).
Given the limited number of eagle observations recorded during the nesting season, and the
timing (peak use in fall and winter) and age distribution of the eagles observed during pre-
construction surveys (eight of 12 known-age birds were adults) it is likely that Wild Horse may be
used more by adult eagles which are likely non-territorial and/or migrants. Observations recorded
during the 2015 eagle use surveys largely consisted of subadult eagles (eight of 13 observations
were classified as subadults), further suggesting that eagle use largely consists of non -territorial
and/or migrant eagles. Although the literature regarding relative risk among age class and
resident status is somewhat limited, it is assumed that potential impacts to eagles are more likely
to affect populations of adult floater and/or subadult eagles than resident adults or juveniles. This
is consistent with golden eagle fatalities that have been documented at Wild Horse, which were
in the subadult age class, suggesting they were non-territorial floaters.
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8.2.5 Prey Availability
Habitat for small mammals is widespread at Wild Horse, with most of the project area providing
habitat for at least some small-mammal species. Small-mammal species that were observed
during pre-construction surveys and are representative of the small mammals occurring on site
include the white-tailed jackrabbit (Lepus townsendii), black-tailed jackrabbit (Lepus californicus),
and ground squirrel (Spermophilus sp.).
No areas of small mammal congregation were noted during pre-construction surveys; however
ground squirrels were noted as being more commonly observed at baseline survey station B
(figure 6), which was located in the southwestern portion of the project. Based on the available
data, it appears that primary prey species (jackrabbits and ground squirrels) are relatively
widespread throughout the project and would therefore not lead to elevated levels of risk to eagles
in any particular area of the project. This is consistent with incidental observations of prey species
during the eagle-specific fatality monitoring and use surveys conducted in 2015.
8.3 Fatality Predictions
The models being used to predict eagle fatality rates at wind energy projects (e.g., USFWS
Bayesian model) are based on the assumption that eagle use is positively correlated to fatality
rates. In their analysis of avian fatalities at the Tehachapi Pass wind complex, Anderson et al.
(2004) found a direct relationship between raptor use and raptor fatalities: areas with the most
raptor use had more fatalities than areas with the least raptor use. Fixed-point surveys provide a
standardized methodology or index that enabled comparisons between projects. In this section,
we present the Service’s approach for assessing the expected level of mortality for golden eagles
at Wild Horse, which provides a quantitative prediction of fatality rates based on estimated eagle
use. Golden eagle use estimated from site-specific field surveys was used to increase consistency
and enable comparison with other studies.
Data collected during avian point count surveys at the project were used with the current Service
Bayesian Collision Risk Model (USFWS 2013) to calculate golden eagle mortality estimates.
Collision risk modeling estimates the number of annual eagle mortalities that are expected at a
wind-energy facility based on eagle use recorded during on-site eagle use surveys. Assuming
that eagle mortality is proportional to pre-construction eagle activity, a Bayesian model was
developed by the Service based on pre- and post-construction golden eagle surveys conducted
at four wind energy facilities, as reported in Whitfield 2009. Bayesian analyses incorporate a prior
belief (or best estimate) regarding model parameters as supporting evidence in determining a
posterior distribution of eagle exposure and mortality. In order to obtain estimates of golden eagle
and bald eagle mortalities at Wild Horse using the Service’s methodology, the following
information was used: 1) eagle minutes (calculated as the number of pre -construction eagle
observations within 800 m of observers that were below 200 m above ground level times the
average number of minutes of similar data collected during post-construction eagle use
monitoring); 2) an estimate of operating time given average wind speed data at Wild Horse; 3)
the quantity of turbines and rotor radius of the turbines at Wild Horse; and 4) the Bayesian collision
probability prior recommended by the Service (USFWS 2013).
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The ECP Guidance (2013) encourages project developers or operators to develop additional
candidate models for comparison with, and evaluation of, the baseline USFWS model and
modeling approach. WEST developed new collision probability priors for the Service’s Bayesian
model from a larger sample of modern wind energy facilities (24 in total) that have data on both
eagle use and eagle fatalities (Bay et al. 2016). This model is referred to as the WEST model and
is presented in this ECP for comparison purposes. Aside from the updated priors, all other aspects
of the model were unaltered from that of the Service. Tables 8-3 through 8-7 contain parameters
used to estimate eagle take based on specifications for the turb ine types in operation at Wild
Horse. The parameter values and results of both the Service and WEST models are included for
comparison purposes, and provide a range of predicted impacts. In this ECP, we use the Service’s
model outputs as the basis for the adaptive management strategy and any mitigation
requirements. Inclusion of the WEST model in this ECP is in line with the aforementioned
recommendation of the ECP Guidance for inclusion of alternative models and is intended to
provide a range of values which can be considered relative to risk of eagle take at Wild Horse.
8.3.1 Exposure Rate Calculations
Exposure rate (𝜆), as defined by the Service (2013), is the expected number of flight minutes at
or below 200 m per daylight hour across the surveyed area (km2). For surveys conducted during
pre-construction studies at Wild Horse, the surveyed area was an 800-m plot around the survey
point. All observations within the 800-m plot that were at or below 200 m above ground level
(AGL) were used for modeling. In addition to the data from Erickson et al. (2003; i.e. the 2002-
2003 baseline survey report described in section 5.2), an additional 10.5 hours of fixed -point avian
use survey data from summer 2003 were included for modeling purposes. Although the data were
not included in Erickson et al. (2003) due to report timing, the methods used for the 10.5 hours of
additional data were the same as those used and presented in Erickson et al. (2003). In total,
there were 103.5 hours of survey effort spread throughout the year (15 hours in spring 2002; 39.5
hours in fall 2002; 7 hours in winter 2002/2003; 31.5 hours in spring 2003, and 10.5 hours in
summer 2003). Sixteen golden eagle observations and one bald eagle observation were recorded
during the 103.5 hours of formal surveys in 2002 and 2003, of which 14 golden eagle observations
and one bald eagle were recorded within the 800-m survey plots at less than 200 m AGL (table
8-3). These methods vary from the methods the Service recommends, since these studies pre-
dated the ECPG and the Service’s Wind Power Guidelines, so the results have been modified per
the Service’s recommendations to fit the current model as described below.
The ECP Guidance (USFWS 2013) recommends using one minute per eagle observation when
observation data were not collected on a minute-by-minute basis, to be consistent with direction
from Service Region 1. We used post-construction eagle observation data (see Section 7.4.2) to
extrapolate the number of pre-construction golden eagle observations to eagle minutes by
multiplying each observation by a factor of four, which was the average number of minutes each
post-construction golden eagle observation was within an 800-m plot at heights at or below 200 m.
This resulted in a total of 56 eagle minutes for the preconstruction use instead of the 14 minutes
that would have been used based on the ECP Guidance recommendations. For bald eagles, the
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one pre-construction bald eagle observation was multiplied by a factor of three (the average
number of minutes each post-construction bald eagle observation was within an 800-m plot at
heights at or below 200 m) for a total of three bald eagle minutes. A 𝐺𝑎𝑚𝑚𝑎(𝛼 = 0.97,𝛽 = 2.76)
prior distribution with mean (0.35) and standard deviation (0.357) is recommended by the Serv ice.
A posterior distribution of golden eagle use at Wild Horse was estimated as a 𝐺𝑎𝑚𝑚𝑎 distribution
with the 𝛼 parameter equal to the sum of the prior 𝛼 and total flight minutes at or below 200 m,
and the 𝛽 parameter equal to the sum of the prior 𝛽 and effort (hours of surveys x km2 of area
surveyed), respectively:
𝑃𝑜𝑠𝑡𝑒𝑟𝑖𝑜𝑟 𝜆 ~
𝐺𝑎𝑚𝑚𝑎[𝛼 + (𝑈𝐺𝐸)(𝑛𝑠𝑢𝑟𝑣𝑒𝑦𝑠)(𝑓𝑙𝑖𝑔ℎ𝑡 𝑚𝑖𝑛𝑢𝑡𝑒𝑠),𝛽 + (𝑠𝑢𝑟𝑣𝑒𝑦 𝑙𝑒𝑛𝑔𝑡ℎ 𝑖𝑛 ℎ𝑟𝑠) ∙ (𝑛𝑠𝑢𝑟𝑣𝑒𝑦𝑠) ∙ 2.01]
For golden eagles, this resulted in a posterior distribution for exposure rate of Gamma (56.97,
210.859) with mean 0.270 eagle flight minutes observed per hour of survey per square km. For
bald eagles, this resulted in a posterior distribution for exposure rate of Gamma (3.97, 210.859)
with mean 0.0189 eagle flight minutes observed per hour of survey per square km (table 8 -3).
These priors were used as the inputs into all runs of the models.
Table 8-3. Values used to calculate exposure rate (λ).
Golden Eagle Bald Eagle Variable USFWS WEST USFWS WEST
1) Recorded Flight Minutes below 200 m at points 56 56 3 3 2) Number of Surveys 207 207 207 207 3) Length of Surveys 0.50 0.50 0.50 0.50 4) Survey Hours 103.50 103.50 103.50 103.50 5) Survey Radius (meters) 800 800 800 800 6) Eagle Flight Minutes (alpha: Line 1 + 0.97) 56.97 56.97 3.97 3.97 7) Effort (beta: survey hours x km2 of area surveyed + 2.76) 210.859 210.859 210.859 210.859 8) Mean Exposure Rate (Line 6 / Line 7) 0.2702 0.2702 0.0188 0.0188
8.3.2 Expansion Factor
A facility-specific expansion factor is multiplied by the eagle exposure rate ( eagle flight minutes
hour ∙km2) to
estimate the potential annual eagle-wind turbine interactions (minutes of flight within the turbine
hazardous area). The expansion factor scales the exposure rate to daylight hours ( 𝜏) within the
seasons that surveys were conducted across the total hazardous area (𝛿𝑖) surrounding all
existing turbines (𝑛𝑡; USFWS 2012):
휀 = 𝜏 ∑ 𝛿𝑖
𝑛𝑡
𝑖=1
The Service defined the turbine hazardous area (𝛿𝑖) as the rotor-swept area around each turbine
or proposed turbine location (km2; USFWS 2012). The expansion factor (휀) was calculated for the
2002-2003 pre-construction survey data for the 149 turbines at Wild Horse (table 8-4). The
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daylight hours (defined as one half hour before sunrise to one half hour after sunset) per year
were calculated based on National Oceanic and Atmospheric Administration (NOAA)
sunrise/sunset data for nearby Ellensburg, Washington. Three turbines that were chosen as being
representative of the Wild Horse project (Turbines A01, D37, and F01) and wind speed data were
compiled for the three turbines for the period January 1, 2007 through May 25, 2015 (almost the
entire operational life of the project to date). From this data it was determined that turbine blades
rotated at more than one revolution per minute (RPM), which equates to blade tip speeds of about
10 miles per hour (mph; [16 kph]) or more, for 77% of all daylight hours. It was assumed that
blades rotating with tips speeds of 10 mph or less would not present a high risk of fatal collision
for eagles. As such, the number of daylight hours of potential exposure per year was calculated
as 77% of the total daylight hours for Ellensburg, WA (table 8-4 Line 9).
Table 8-4. Values used to calculate expansion factor (ɛ).
Golden Eagle Bald Eagle
Variable USFWS WEST USFWS WEST
9) Hours per year 3440 3440 3440 3440
10) Rotor Radius (meters) 40 40 40 40
11) Turbine Hazardous Area (pi * radius of turbine in km2) 0.005 0.005 0.005 0.005
12) Number of Turbines (127 in 2007, 149 in 2010, 2012, 2015)
127/149 127/149 127/149 127/149
13) Expansion Factor (Line 9 x Line 11 x Line 12; 2007 expansion factor / 2010, 2012, 2015 expansion factor)
2196.00/
2576.41
2196.00/
2576.41
2196.00
/2576.4
1
2196.00/
2576.41
8.3.3 Collision Correction Factor
The collision correction factor (collision probability;𝐶) was defined as the probability of an eagle
colliding with a turbine given each minute of eagle flight in the turbine hazardous area. The prior
distribution for collision probability was developed by the Service using the four previous fatality
studies reported in Whitfield (2009). A weighted mean of the estimated flight minutes within the
turbine hazardous area versus recorded collision events at those facilities was used to determine
a Beta (2.31, 396.69) prior distribution for collision probability, with mean and standard deviation
of 0.0058 and 0.0038 eagle fatalities per minute of flight in the turbine hazardous area,
respectively (table 8-5). The prior distribution for the WEST model was based on 24 projects, and
has a Beta (9.28, 3224.51) prior distribution for collision probability with mean and standard
deviation of 0.0029 and 0.0009 eagle fatalities per minute of flight in the turbine hazardous area.
Table 8-5. Values used to calculate the baseline collision correction factor C. Priors were updated
through incorporation of post-construction mortality data in each successive run of the Bayesian models.
Golden Eagle Bald Eagle
Variable USFWS WEST USFWS WEST
14) Prior Fatalities 2.31 9.28 2.31 9.28
15) Prior exposure events not resulting in fatality 396.69 3224.51 396.69 3224.51
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16) Prior mean collision correction factor (Line 14/(Line 14 + Line 15))
0.00579 0.00287 0.00579 0.00287
Post-construction fatality monitoring studies at Wild Horse provide additional information
applicable to predicting eagle fatality rates, with fatality monitoring conducted in 2007, 2010, and
2012 to estimate the impacts of the project on birds and bats in general, and in 2015 to specifically
estimate project impacts on eagles. The number of eagle fatalities estimated for each year of
fatality monitoring was calculated by the Service (M. Stuber, USFWS), using the Fatality Capture
Mark Recapture software package (FCMR; Peron and Hines 2014) and the searcher efficiency
data from the appropriate years and the carcass persistence data from the 122-day raptor-specific
removal trial conducted in 2016 (Table 8-6). The 2007 fatality study included a sampling of the
original 127 turbines at Wild Horse, while the 2010 study included a sampling of all 149 turbines,
the 2012 study included a sampling of only the 22 expansion area turbines, and the 2015 study
included all 149 turbines (Table 8-6). The resulting fatality estimates were used to update the
collision priors (lines 14-16 in Table 8-5) for each of four successive runs of Bayesian models
based on the 2007, 2010, 2012, and 2015 data.
The primary influence of the post-construction data is updates to the collision priors. For example,
the fatality estimate for 2007 (0.15 eagles) was added to the fatality prior of 2.31 to produce a
posterior fatality estimate of 2.46, which was then used as the prior in the next run of the model.
The same was done for the number of exposure events not resulting in a fatality (i.e., line 15 of
Table 8-5 was updated with the 2007 data). These two updated posterior values are used to
calculate the posterior collision correction factor in each model run.
Table 8-6. Eagle fatality estimates derived from Fatality Capture Mark Recapture (Peron and Hines
2014) software applied to four years of fatality monitoring data at Wild Horse.
Monitoring
Year
Number of Turbines Searched / Total # of
Turbines
FCMR Fatality Estimate
Golden Eagle Bald Eagle
2007 64 / 127 0.15 0.15
2010 56 / 149 0.28 0.28
2012 10 / 149 1.60 1.60
2015 149 / 149 1.37 0.03
8.3.4 Estimation of Take
The Service’s Bayesian collision risk model (USFWS 2013) assumes that higher site -specific
eagle flight activity will translate to higher annual eagle mortality once the wind energy facility is
operational. Under this assumption, predictions of annual eagle mortality ( 𝐹) were modeled as
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the pre-construction measure of eagle exposure (𝜆) within areas of potential eagle-wind turbine
interactions (휀) multiplied by a collision correction factor (𝐶):
𝐹 = 휀𝜆𝐶
Credible intervals (i.e., a Bayesian confidence interval) were calculated using a simulation of
10,000 Monte Carlo draws from the posterior distribution of eagle exposure (𝜆) and the collision
probability distribution (𝐶; Manly 1991). The product of each of these draws with the exposure
area was used to estimate the distribution of possible fatalities at Wild Horse. The upper 80 th
percentile of this distribution is recommended by the Service as a conservative estimate of the
predicted take for the project of interest (USFWS 2013).
As noted above, the four years of fatality monitoring data were incorporated into the Bayesian
models to produce a final fatality prediction and upper 80% credible interval for Wild Horse based
on all four years of available data. The resulting predicted point estimate of golden eagle take at
Wild Horse was 1.29 fatalities per year, with an upper 80 th percentile of the golden eagle fatality
prediction being 1.72 fatalities per year. For bald eagles, the predicted point estimate was 0.36
fatalities per year, with an upper 80 th percentile of 0.53 bald eagles per year. Based on the WEST
model, the upper 80th percentiles were 0.1.86 golden fatalities per year and 0.23 bald eagle
fatalities per year. Based on the pre-construction use data and post-construction mortality
monitoring data, the resulting upper 80 th percentiles from the two versions of the Bayesian model
(WEST and Service models, respectively) indicate the predicted number of golden eagle fatalities
at Wild Horse is between three and nine for the 5-year permit term and about 20 to 52 over 30
years (table 8-7). For bald eagles, the two models (WEST and Service models, respectively)
predict up to three bald eagle fatalities in five years and roughly three to six over 30 years (table
8-7).
Table 8-7. Eagle Fatalities per Year (F)
Golden Eagles Bald Eagles
Variable USFWS WEST USFWS WEST
Predicted annual eagle fatalities (2007 model run) 1.47 1.46 0.23 0.12
Upper 80th Percentile (2007 model run) 2.15 1.86 0.35 0.17
Predicted annual eagle fatalities (2010 model run) 1.13 1.49 0.27 0.14
Upper 80th Percentile (2010 model run) 1.63 1.90 0.41 0.20
Predicted annual eagle fatalities (2012 model run) 1.27 1.51 0.39 0.16
Upper 80th Percentile (2012 model run) 1.74 1.89 0.57 0.23
Predicted annual eagle fatalities (2015 model run) 1.29 1.49 0.36 0.16
Upper 80th Percentile (2015 model run) 1.72 1.86 0.53 0.23
Predicted total over 5-year permit term (2015 model run)
8.62 9.29 2.64 1.14
Predicted total over 30 years (2015 model run) 51.73 55.75 15.81 6.82
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8.3.5 Observed Injury and Fatality Rates
For comparison to the estimated fatality rates provided above, observed fatality rates are also
discussed. The initial phase of Wild Horse (127 turbines) commenced commercial operations in
December 2006, while the expansion (22 turbines) commenced operations in November 2009.
Formal fatality monitoring studies were conducted at the project over a period of three years
(2007, 2010, and 2012), during which no eagle fatalities were documented. In addition to the
formal fatality monitoring studies conducted, as described in section 6.3, PSE maintains an
ongoing incidental wildlife monitoring program, (WIRHS), which provides training to site personnel
regarding identification of project-related fatalities and an associated reporting system which is
used to track annual bird and bat fatalities for the life of the project. In addition, PSE implemented
one year of eagle fatality monitoring and eagle use surveys to support the development of this
ECP and permit process from March 2015 to March 2016 (section 7.2).
As noted in section 2.2.2, PSE identified two sub-adult golden eagle fatalities in June 2014, one
sub-adult golden eagle fatality discovered during eagle fatality monitoring in April 2015, and one
additional incidentally-discovered sub-adult golden eagle fatality in September 2016. No bald
eagle fatalities have been documented to date at Wild Horse.
8.4 Population Status and Local Area Thresholds
Golden Eagle
For assessing impacts of authorized take on golden eagle populations, the Service (2016) now
reviews project impacts at both an eagle management unit (EMU) scale and at a local area
population (LAP) scale. In 2016, the Service revised the EMUs to now be based on the Service’s
administrative flyways; whereas they were previously (USFWS 2009) based on defined Bird
Conservation Regions (BCRs; Rich et al. 2004). The Service (2016) also revised the LAP scale
to be an area encompassing a 109-mi buffer surrounding the project of interest for golden eagles
(previously 140 mi). Wild Horse lies within the Pacific Flyway EMU, which has an estimated
population of 15,927 golden eagles according to the Service (2016).
The Service has identified take rates of between 1% and 5% of the estimated total eagle
population size at the LAP scale (109-mi buffer surrounding the project for golden eagles) as
significant; with 5% being at the upper end of what might be appropriate under the BGEPA
preservation standard, whether offset by compensatory mitigation or not (USFWS 2013).
The Service (2016) recommends calculating the local-area 5% benchmark as follows:
(Local-area * Regional Eagle Density) * 0.05
A 109-mi buffer surrounding Wild Horse overlaps three BCRs; the Great Basin (BCR 9; 82,500.7
km2 [31,853.5 mi2]), the North Pacific Rainforests (BCR 5; 15,815.6 km2 [6,106.4 mi2]), and the
Northern Rockies (BCR 10; 2,375.1 km2 [917.0 mi2]). To calculate the LAP for golden eagles
associated with Wild Horse, eagle population estimates for individual BCRs from the Service’s
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(2016) status report were used to develop density estimates for each BCR. The density within
each BCR was then applied to area of the BCR that fell within the LAP buffer for Wild Horse to
determine the LAP size for golden eagles. Using the density estimates calculated based on the
2016 status report populations (USFWS 2016) for golden eagles in BCR 9 (0.0095 eagles/km2),
BCR 10 (0.0110) and BCR 5 (0.0011 eagles/km2), the equation above results in an estimated
local area population size of approximately 823 golden eagles for the Wild Horse LAP (within 109
miles of the project) and a local-area 5% benchmark of 41 eagles taken annually. Assuming a
golden eagle fatality rate of about 1.72 per year (Table 8-7) at Wild Horse, this equates to 0.21%
of the total local-area population and 4.2% of the local-area 5% benchmark. Recent analyses of
summer golden eagle populations across the western US indicate that golden eagle populations
in BCRs 5, 9, and 10 have been stable over about the past decade (Millsap et al. 2013, Nielson
et al. 2014) and potentially increasing since the late 1960’s (Millsap et al. 2013).
Bald Eagle
For assessing impacts of programmatic take on bald eagle populations, the Service (2009)
defined bald eagle management units that were largely based on Service regional boundaries.
Consistent with the EMUs for golden eagles, the EMUs for bald eagles were also revised to
coincide with the Service’s administrative flyways, with some modifications (USFWS 2016).
Based on the new EMUs, Wild Horse falls within the central portion of the Pacific Flyway, which
spans from 40 degrees latitude to the Canadian border. For estimation of the LAP, the same
criteria discussed above for golden eagles was also applied to bald eagles, except that the LAP
size has been revised from a 43-mile buffer around the project to an 86-mi buffer around the
project (USFWS 2016) and the eagle density estimate is derived from the population estimates
provided in the 2016 status report (USFWS 2016) applied to the Service’s regional boundaries
instead of BCRs.
An 86-mi buffer surrounding Wild Horse is located entirely within the Pacific Flyway and within
Service region 1. To calculate the LAP for bald eagles associated with Wild Horse, eagle
population estimates for the Pacific and Northern Rocky Mountain bald eagle EMUs from the
Service’s (2016) status report were used to develop density estimates for Region 1, based on the
proportion of each EMU population that fell within region 1 area. The density estimate was then
used to extrapolate to the LAP area for Wild Horse. Therefore the 5% benchmark for the local
area population is calculated as the density of bald eagles multiplied by the local area size (i.e.,
project plus 86-mi buffer) multiplied by 5%:
0.044 bald eagles/mi2 *24,541.6 mi2 * 5% = 54.0 bald eagles.
Based on this calculation, the local-area 5% benchmark would be 54 bald eagles taken annually.
Assuming a bald eagle fatality rate of 0.53 per year (table 8-7), this equates to 0.05% of the local-
area population of 1,080 bald eagles and 0.98% of the local-area 5% fatality benchmark of 54
bald eagles. In Washington, bald eagle populations have been steadily increasing in recent
decades. Stinson et al. (2007) reported annual average population increases of 9% per year
during the 25 years preceding their report (1980-2005) and recommended to down-list the species
from state threatened to state sensitive. Given that the estimate of bald eagle take is less than
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1% of the take threshold for the local-area population estimate, compensatory mitigation is not
expected to be required for bald eagles, per Service regulations, although any mitigation
completed for golden eagles is also likely to benefit bald eagles.
8.5 Cumulative Impacts
According to the ECP Guidance (USFWS 2013), cumulative impacts are evaluated at both the
management unit and the local-area population level. Both analyses require an understanding of
the anthropogenic sources of eagle mortality at these two scales. The objective of the analysis at
the local area level is to identify cases where new authorized take would, either by itself, or
cumulatively in combination with other known sources of ongoing take, exceed 5% of the
estimated local-area population of eagles. As noted in the previous section, the predicted level of
take for both bald eagles and golden eagles at Wild Horse is well below the 5% thresholds for the
LAP; however, because the amount of publicly available data on eagle mortality within the region
is limited, the total cumulative impacts of eagle mortality within the LAP associated with Wild
Horse will be addressed by the Service during the NEPA process, and not in this ECP.
8.6 Electrocution Risk
The construction of electrical infrastructure at Wild Horse is consistent with the recommendations
of the Avian Power Line Interaction Committee for avian-safe power line design (APLIC 2006).
The majority of electrical distribution lines were placed underground to minimize hazardous
perching locations and electrocution risk for birds. In addition, the overhead distribution lines were
built consistent with PSE’s avian safe standards, including 11-foot cross-arms which provide
sufficient spacing between conductors to prevent eagle and raptor electrocutions. The overhead
transmission lines pose very low risk to raptors (APLIC 2006).
One of the mitigation measures identified in the FEIS issued by EFSEC was equipping all
overhead transmission pole structures with perch guards to minimize electrocution risk to raptors.
Through an adaptive management process, the Wild Horse TAC determined that the installation
of perch deterrents was not necessary because electrocution of raptors on transmission
structures is rare, and these structures at Wild Horse were built avian-safe, therefore posing very
low risk to raptors.
8.7 Categorizing Site According to Risk
Site risk categorization from the ECP Guidance is based on: 1) whether or not there are important
eagle use areas3 or migration concentration sites within the project footprint or area; 2) the value
of the predicted fatality estimate (i.e., is it less than or greater than 0.03 eagles per year or one
eagle over the life the project, 3) whether the annual predicted eagle fatality estimate is greater
than 5% of the estimated local-area population size; and 4) whether fatalities at the project would
3 The definition of an important eagle use area from the ECP Guidance is as follows: “an eagle nest, foraging area, or communal roost
site that eagles rely on for breeding, sheltering, or feeding, and the landscape features surrounding such nest, foraging area, or
roost site that are essential for the continued viability of the site for breedi ng, feeding, or sheltering eagles”.
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cause the cumulative annual take for the local-area population to exceed 5% of the estimated
local-area population size.
Wild Horse does not appear to have any important eagle use areas or migration concentration
sites within its footprint. The fatality estimate is greater than 0.03 eagles per year for both golden
and bald eagles, but is less than 5% of the estimated local-area populations. While the cumulative
impacts are not fully understood, the estimated take of one to two eagles per year should not
cause cumulative annual take to exceed 5% of the estimated local-area population. Based on this
information, Wild Horse should be considered a Category 2 project. Based on the projected risk
to bald and golden eagles, as discussed in the above sections, PSE is requesting coverage under
a 5-year incidental eagle take permit for Wild Horse for up to nine golden eagles and three bald
eagles.4.
9.0 Ongoing Monitoring
Ongoing monitoring and reporting are crucial elements for successfully implementing the Wild
Horse ECP. According to the ECP Guidance, the U.S. Fish and Wildlife Service recommends a
formal standardized protocol for periodic ongoing eagle fatality monitoring during the 5 year permit
term. PSE is proposing a variety of monitoring protocols, including operational search and scan,
drone, and incidental monitoring methods. These three types of monitoring are outlined in table
9-1, and described in detail in the following sections.
Pending permit issuance, PSE will conduct formal operational monitoring in Years 1, 2, and 3 of
the permit, and will continue to provide training to on-site staff to identify eagle fatalities found
incidentally during regular turbine inspections consisten t with the WIRHS and PSE’s Special
Purpose Utility Permit (SPUT). If the number of eagle fatalities found meet the triggers identified
in the Adaptive Management process (section 11/tables 11-1/11-2), additional years of monitoring
may be conducted if warranted as determined through consultation with USFWS. On-site
personnel will continue to conduct incidental monitoring as per the SCA throughout the 5 -year
permit term.
Table 9.1 PSE’s Wild Horse Eagle Fatality Monitoring Plan
Permit
Year
Timing Fatality Monitoring Reporting
1 Fall 2019-fall 2020
(or within 3 months
of permit issuance)
Conduct formal operational fatality
monitoring on a quarterly basis. Methods
will include:
Drone surveys at all turbines
Scan surveys at a sample of 1/3rd of turbines randomly selected.
Provide incidental and annual
reporting to USFWS OLE and
RMBPO consistent with WIRHS
and PSE’s SPUT Permit
4 Request for coverage for predicted take of 10 golden eagles in 5 years is a conservative estimate based on the Bayesian model
updated with estimated fatality rates at Wild Horse.
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Searcher efficiency (SE) trials for drones and on-site staff (both incidental and scan detections) SE trials will include decoys or
surrogates representing 3 different carcass decay stages
Fatality estimates in Y1 will use lowest SE value
Raptor carcass persistence results from 2016 spring/summer studies
Raptor carcass persistence trial results from 2019-2020 fall/winter studies.
Vegetation mapping and refining survey methods at each turbine depending on detectability
Continue to implement incidental
monitoring procedures monthly at all
turbines during regular operations and
maintenance activities.
2 Fall 2020-fall 2021 Conduct formal operational fatality
monitoring at all turbines on a quarterly
basis. If results of Y1 SE for all decay
stages (and g-value) are very low, and
more frequent surveys are warranted,
frequency will increase.
Methods will include:
Drone or scanning surveys at all turbines
Fatality estimates in Y2 will be updated using SE values from Y1 trials
Raptor carcass persistence results from 2016/2019 studies
Vegetation mapping and refined survey methods at each turbine depending on detectability
Continue to implement incidental
monitoring procedures monthly at all
turbines during regular operations and
maintenance activities.
Develop and submit to USFWS the
Y1 fatality monitoring report,
including results of searcher
efficiency trials, raptor carcass
persistence data, and visibility class
information with the adjusted fatality
estimate. Third party will provide
technical support for developing the
report and updated take estimates.
Provide incidental and annual
reporting to USFWS OLE and
RMBPO consistent with WIRHS and
PSE’s SPUT Permit
3 Fall 2021-fall 2022 Conduct formal operational fatality
monitoring at all turbines on at least a
quarterly basis. Methods will include:
Drone or scanning surveys
Develop and submit the Y2 fatality
monitoring report, including results
of searcher efficiency trials, raptor
carcass persistence data, and
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Searcher Efficiency trials
Fatality estimates for Y3 will be updated using results of Y3 SE trials
Raptor carcass persistence results from 2016/2019 studies
Vegetation mapping and refined survey methods at each turbine depending on detectability
Continue to implement incidental
monitoring procedures monthly at all
turbines during regular operations and
maintenance activities.
Using the adaptive management strategy
(section 11/table 11-1/11-2) determine if
additional monitoring is warranted in
consultation with USFWS based on PCM
fatality estimates/ number of eagles found
to date.
visibility class information with the
updated fatality estimate. Third party
will provide technical support for
developing the report and updated
take estimates.
Provide incidental and annual
reporting to USFWS OLE and
RMBPO consistent with WIRHS and
PSE’s SPUT Permit
4 Fall 2022- fall 2023 Continue to implement incidental
monitoring procedures monthly at all
turbines during regular operations and
maintenance activities.
If additional monitoring is warranted,
conduct formal operational fatality
monitoring at all turbines on at least a
quarterly basis. If g-value for Y1-3 is less
than 0.4, implement measures to increase
g-value. Monitoring methods will include:
Drone or scanning surveys
Fatality estimates for Y4 will be updated using SE values from Y3 trials
Raptor carcass persistence results from 2016/2019 studies
Vegetation mapping and refined survey methods at each turbine depending on detectability
Using the adaptive management strategy
(section 11/table 11-1/11-2) determine if
additional monitoring is warranted in
consultation with USFWS based on PCM
Develop and submit the Y3 fatality
monitoring report, including results
of searcher efficiency trials, raptor
carcass persistence data, and
visibility class information with the
adjusted fatality estimate. Third
party will provide technical support
for developing the report and
updated take estimates.
Provide incidental and annual
reporting to USFWS OLE and
RMBPO consistent with WIRHS and
PSE’s SPUT Permit.
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fatality estimates/ number of eagles found
to date.
5 Fall 2023- end of
permit term
Continue to implement incidental
monitoring procedures monthly at all
turbines during regular operations and
maintenance activities.
If additional monitoring is warranted,
conduct formal operational fatality
monitoring at all turbines on at least a
quarterly basis fall 2023 – winter 2024 (or
within 3 months of permit expiration).
Methods will include:
Drone or scanning surveys
Fatality estimates for Y4 will be updated using SE values from Y3 trials
Raptor carcass persistence results from 2016/2019 studies
Vegetation mapping and refined survey methods at each turbine depending on detectability
Compile monitoring data, complete
monitoring report, and prepare for permit
reapplication.
Develop and submit the 5-year
fatality monitoring report, including
compiled results of the 5 years of
monitoring, including formal
operational drone/scan monitoring
results, incidental monitoring results ,
searcher efficiency trials, raptor
carcass persistence,
visibility/vegetation mapping, overall
PCM fatality estimates, and any
other prudent information (prey
species, incidental eagle
observations, etc.) Third party will
provide technical support for
developing the report and updated
take estimates.
Provide incidental and annual
reporting to USFWS OLE and
RMBPO consistent with WIRHS and
PSE’s SPUT Permit
9.1 Operational Monitoring Protocol
The objective of standard post-construction fatality monitoring (section 7.1) is to statistically
estimate an overall site-wide fatality rate for birds and bats using a relatively small sampling of
turbines, typically about 30 percent (Strickland et al. 2011), that results in a relatively large
sampling of carcasses (> 10). Thus, standard post-construction fatality monitoring methods are
not well suited for estimating rare events such as eagle fatalities. In addition , eagle fatality
monitoring of all turbines using standard post-construction fatality monitoring methods commonly
implemented for wind projects (i.e., third party pedestrian transects) would be cost -prohibitive in
the long term; thus, operational eagle fatality monitoring offers another option for detecting eagle
fatalities and estimating the site-wide fatality rate. Operational eagle fatality monitoring is a
systematic approach intended to be carried out by site operations personnel and result in a high
likelihood of detecting any eagle fatalities which may occur on the Project. The overarching
purpose of operational eagle fatality monitoring is to verify that the actual amount of eagle take is
within the permitted amount of take.
For operational monitoring to be effective, eagles must have a long persistence time and on-site
personnel must have a high likelihood of detecting carcasses (i.e., searcher efficiency). Based on
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raptor persistence trials in 2016, raptors meet the criteria of long persistence time s. On-site
personnel at Wild Horse are trained to detect and document avian and bat carcasses found
incidentally while performing normal operations and maintenance activities. In addition, eagle
fatalities are regularly found incidentally at wind energy facilities (Pagel et al. 2013), suggesting
that on-site personnel readily detect eagles because of their large size.
PSE proposes operational eagle fatality monitoring protocols in years 1, 2, and 3 of the permit
term (table 9-1), with additional years of monitoring if determined to be warranted under the
adaptive management process in consultation with the Service. The proposed methods would
use on-site personnel to implement a systematic survey of the wind turbines at the facility to
estimate the number of eagle fatalities at the project based on the following: 1) the number of
eagle fatalities identified; 2) the 2016 and 2019 raptor carcass persistence data; and 3) searcher
efficiency trials that account for variation in survey methods, carcass decay stages, and
detectability due to visibility (vegetation/cover and topography). As on-site personnel regularly
visit wind turbines at the wind facility throughout their normal activities, operational eagle
monitoring would be cost-effective in the long term, and with searcher efficiency and raptor
carcass persistence trials, would provide assurance that eagle fatalities occur ring at the project
would be detected and overall fatality rates could be accurately calculated.
Two separate formal monitoring protocols are proposed for Year 1 to test the two methods and
gather the data needed to determine effectiveness of the two types of surveys. PSE is currently
developing an Unmanned Aerial Vehicle (UAV) or drone monitoring program, and is proposing to
survey all turbines on a quarterly basis in Year 1. A second protocol, the search and scan method,
is also proposed for Year 1 monitoring to be implemented at a sample 1/3 rd of turbines for
comparing effectiveness. Searcher efficiency trials will be conducted for both survey types. Based
on results of the Year 1 monitoring, including fall and winter raptor carcass persistence, searcher
efficiency for different decay stages, and overall fatality estimates, monitoring methods will be
refined for monitoring years 2 and 3, with the intention of achieving g-values (i.e., the site-wide
probability of detection) for the 3-year monitoring period of 0.40 or greater.
9.1.1 Drone Monitoring Methods
PSE is proposing a protocol for eagle fatality monitoring with the use of a small unmanned aircraft
system, or drone, where on-site personnel who are authorized to do so, fly a drone around each
turbine or string of turbines searching for eagle fatalities. The drone will be flown in a pattern
similar to that of walking transects to cover a plot size of at least 120m in each direction from the
turbine (240m square plot). This method is expected to provide coverage of the area where most
(99% or more) of large raptor carcasses are likely to fall based on the turbine sizes in use at Wild
Horse (Hull and Muir 2010). Search plots and flight transects will incorporate a 30 -foot buffer
around each turbine base and a flight height below the lowest point of the wind turbine blade
(27m), and will be automatically generated based on sensor type, plot size, speed, and flight
height using a professional drone software application. The drone will be flown at a speed of
approximately 5 meters per second (m/s) and a height of approximately 15-25 meters, depending
on topography and visibility, to provide full coverage of the search area. High resolution imagery
from the drone’s onboard camera is captured for each search plot , and then analyzed by Machine
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Learning techniques using a combination of ESRI tools and TensorFlow to detect any potential
eagle fatalities. If an eagle or eagle-like shape is detected in the imagery, on-site staff will respond
quickly to review the imagery and confirm findings in the field. To establish the effectiveness of
drone eagle fatality monitoring, PSE will conduct trials to estimate the searcher efficiency of
drones operated by on-site personnel using decoys and/or surrogate carcasses representing
three different decay stages (fresh, desiccated but intact, and feather spot) to account for the
quarterly search interval. In addition, decoys and/or surrogate carcasses in various decay stages
and during all seasons will be used to classify images, which will be used to support Machine
Learning in detecting eagles.
9.1.2 Operational Search and Scan Monitoring Methods
To compare the effectiveness of drone monitoring, PSE is proposing a second protocol where on-
site personnel, on a quarterly basis, drive slowly (< 10 mph) along turbine access roads while
looking for eagle carcasses with search and scan surveys occurring at a random sampling of one -
third of the turbines. At the turbine base, the person conducting the survey would exit the vehicle
and scan the surrounding terrain for eagle carcasses. Using a range-finder and binoculars, each
quadrant of the four cardinal directions would be scanned out to 120 meters from the turbine base.
This distance is expected to provide coverage of the area where most (99% or more) of large
raptor carcasses are likely to fall based on the turbine sizes at Wild Horse (Hull and Muir 2010).
To establish the effectiveness of operational eagle fatality monitoring, PSE will conduct trials to
estimate the searcher efficiency of on-site personnel using decoys and/or surrogate carcasses
representing three different decay stages (fresh, desiccated but intact, and feather spot) to
account for the quarterly search interval.
Searcher Efficiency Trials
In order to estimate searcher efficiency, trial “carcasses” consisting of plastic turkey decoys
covered with a feathered shroud will be used as a proxy for eagle carcasses, because unlike
natural carcasses typically used for trials (e.g., hen pheasants or hen mallards) the feathered
decoys are not likely to attract scavenging eagles or other raptors. Further, the feathered decoys
are more similar in size and color to eagle carcasses. The feathered decoys will be placed at
randomly selected turbines stratified by visibility class, and some decoys will be modified or other
surrogate carcasses to represent three different carcass decay stages (fresh, desiccated but
intact, and feather spot) to simulate detectability of carcasses that may be found with a longer
search interval.
Carcass Persistence Trials
Raptor-specific carcass persistence trials were conducted in spring/summer 2016 to estimate the
average length of time an eagle carcass remains in the study area and available for detection.
Carcass persistence trials began on May 14, 2016, concurrent with formal eagle fatality
monitoring, and consisted of a 122-day trial period and 19 raptor carcasses. On day 86, 17 of the
19 carcasses were still detectable and on day 122 (end of the trial) nine of the 19 were still
detectable, suggesting that raptor carcasses meet the criteria of long persistence and a quarterly
(~90 day) search interval is sufficient for eagle fatality monitoring at Wild Horse. PSE is proposing
to conduct additional raptor carcass persistence trials in fall/winter 2019 during Year 1 operational
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eagle fatality monitoring to assess seasonal variability, and the results, combined with the 2016
results, will be used to adjust estimates of annual mortality for removal bias.
9.2 Analysis
9.2.1 Visibility/Detection Mapping
Maps were created during the formal eagle fatality monitoring studies completed in 2015-2016.
Three visibility classes were included (easy, medium, and difficult) for search plots based on aerial
photography, land cover/habitat mapping, topography, and on-the-ground verification. During the
drone searcher efficiency trials, detection probability will also be tested to see if there are
differences in detectability by vegetation type with the use of a drone vs. operational staff. If areas
are identified to be difficult to survey using the search and scan method, and drone monitoring
has higher detectability, those areas will be surveyed using the drone monitoring methods in
subsequent monitoring years.
9.2.2 Site-wide Probability of Detection
The following formula will be used to evaluate the efficacy of the operational eagle monitoring
methods to identify eagle carcasses:
𝑔 = �̂� × 𝑎 ̂ × �̂�
Where 𝑔 is the site-wide probability that a carcass is available for detection and detected, �̂� is the
probability that a carcass persists until the next search, �̂� is the probability that a carcass lands in
a searched area, and �̂� is the probability that a carcass that is in the search area is detected.
Because 𝑔 must be relatively high for operational eagle monitoring to be considered a viable
method, all three other parameters used to estimate 𝑔 must also be relatively high.
In addition to the operational and drone eagle fatality monitoring, operations personnel will
continue to document incidentally detected carcasses using the WIRHS, which will continue for
the life of the project (section 6.3). While the incidental monitoring and reporting related to the
WIRHS program may increase the overall probability of detection, only the calculated estimate of
�̂� , based on actual bias trial data, will be used in the estimation of eagle fatalities for years during
which formal monitoring occurs. In years when no formal monitoring occurs, the annual fatality
estimate will be based on eagle fatalities found incidentally.
9.2.3 Interpretation of Carcasses Found
If an eagle fatality is detected, PSE will use the site-wide probability of a carcass being available
and detected, based on raptor carcass persistence, searcher efficiency, and the proportion of
areas searched to estimate the total number of fatalities for the site that year. Site-wide probability
of a carcass being available and detected will be determined based on the best scientific data for
the site at the time when the eagle fatality is detected, including searcher efficiency, carcass
persistence, and detectability (viewable area). Images collected during drone surveys will be
viewed in real time whenever possible, so that if an eagle is detected, on-site staff can respond
quickly. Any eagle carcasses found will be handled and reported consistent with PSE’s SPUT
permit and the WIRHS.
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9.2.4 Adjustments to Protocol
PSE and a third party will evaluate the searcher efficiency and raptor carcass persistence trial
results for both search/scan and drone survey methods to determine if conducting quarterly eagle
fatality monitoring results in an adequate probability of finding an eagle carcass (e.g., g -values
greater than 0.40). Depending on which method (search/scan or drone) provides a higher
detection probability, a valid monitoring approach, and better meets the monitoring o bjectives
overall, PSE will continue to apply that method in subsequent monitoring years. If detection levels
by on-site personnel or drones are low (e.g., <0.40 over first 3 years of monitoring) or inconsistent,
or a longer search interval is inadequate, then PSE and third party will modify the monitoring
protocol in consultation with FWS to increase the likelihood that an eagle fatality is detected, and
that the eagle fatality rate is accurately estimated.
If methodologies are combined (e.g., drones are used to supplement search/scan monitoring),
then separate probability of detection functions �̂� will be estimated for each survey method and
then combined to determine an overall site-wide probability of available and detected (𝑔). Similar
such methods have been used in other fatality monitoring studies when variable methods have
been applied (e.g., full plot searches vs roads and pads used in Evidence of Absence analysis
related to listed bat species).
During the development of the monitoring plan and proposed protocol, PSE and WEST simulated
scenarios based on known or estimated detection and persistence trial results to determine if
quarterly operational or drone eagle fatality monitoring, as described above, will result in adequate
probability of finding an eagle carcass and provide data adequate for evaluation of exceeding
permitted levels of take using an Evidence of Absence (EoA) approach. All simulations assumed
a 120-m radius search plot and incorporated the carcass persistence data from the 2016 raptor
carcass persistence trials. Within the simulations, we varied the searcher efficiency (50% and
70% for operations personnel, and 80% for drones), and the proportion of turbines searched
(sample of 50% of turbines or all turbines). Given the variation in parameters, simulations resulted
in a site-wide probability of detection (g-hat) ranging from 0.23 (50% searcher efficiency and 50%
of turbines searched) to 0.71 (80% drone searcher efficiency, 70% ops searcher efficiency, all
turbines searched). Under the lower range probability of detection, documentation of one eagle
found results in a 50% probability that the actual take was three or fewer and an 80% probability
that it was seven or fewer. If no eagles were found, then the 50% probability is zero, and the 80%
probability is three or fewer. In contrast, assuming the higher searcher efficiency rates and
searches of all turbines, documentation of one eagle found results in a 50% probability that the
actual take was one or fewer and an 80% probability that it was three or fewer. If no eagles were
found, this scenario results in 50% and 80% probabilities that the actual number of eagles was
zero. The monitoring protocol described in this section was developed based on the results of
these simulations, in order to achieve the desired site-wide probability of detection and a feasible
level of survey effort. If the results of the first year of monitoring, including searcher efficiency and
fall/winter raptor carcass persistence trials indicate that adjustments to the protocol are warranted,
PSE and WEST will refine methods as needed. These adjustments may include increasing the
frequency of surveys, implementing methods to increase searcher efficiency, or combining survey
types depending on detectability at a given turbine.
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9.3 Incidental Monitoring Protocol
As described in section 6.3, PSE has implemented incidental monitoring procedures under the
SCA and consistent with PSE’s APP to identify and respond to eagle and other wildlife fatalities
within the project area that are discovered by onsite personnel during regular operations
maintenance activities. The effectiveness of on-site personnel locating eagle fatalities during the
course of regular activities has been documented throughout the wind industry, and to date
operations personnel have reported the majority of documented eagle fatalities (Pagel et al.
2013). Three of the four known golden eagle fatalities at Wild Horse were identified through
incidental monitoring procedures.
Due to the ongoing WIRHS program and training occurring throughout the life of the project, which
is in addition to the formal operational and drone eagle fatality monitoring, the overall probability
of finding an eagle carcass will be greater than that calculated for the operational and/or drone
monitoring alone. If eagle fatalities are found incidentally during formal monitoring years within
search plots between scheduled searches, then the assumption will be made that the fatality
would have been found during the next scheduled survey, and the fatality will be included when
calculating the annual fatality estimate in formal monitoring years. For years when no formal
monitoring occurs, the annual fatality estimate will be based on incidentally identified eagle
fatalities, incorporating searcher efficiency results for on-site personnel.
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Figure 14. WIRHS process map
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10.0 OFFSETTING COMPENSATORY MITIGATION
As stated above in section 8.4, given that the estimate of bald eagle take is approximately 1% of
the take threshold for the local-area population estimate, PSE does not expect that the Service
would require compensatory mitigation for bald eagles, given the Service regulations. Therefore,
this section focuses on compensatory mitigation for predicted golden eagle mortality associated
with Wild Horse.
The Service, in its study and evaluation of cumulative effects, accounted for fatalities associated
with wind projects that were operational prior to conducting their baseline for determining effects
and population status for golden eagles, which include the Original Wild Horse Project. Because
the original project of 127 turbines was included in the baseline for determining the effects of take
on the population status for golden eagles, fatalities associated with the original project do not
require offsetting compensatory mitigation, so PSE is not required to mitigate for eagle fatalities
associated with the original project. Predicted golden eagle fatalities associated with the original
project will be addressed as needed through the adaptive management process (section 11). In
contrast, the Wild Horse Expansion was not included in the Service’s baseline; therefore predicted
golden eagle take for the expansion will be mitigated with quantifiable offsetting compensatory
mitigation.
The predicted golden eagle take for the Wild Horse expansion portion requiring mitigation was
calculated for the 22 post-baseline turbines. To calculate this, we used the final exposure rate for
the entire project (0.2702) and the collision probability from the final Bayesian model update that
incorporated the 2015-2016 eagle fatality monitoring data (0.00186) with an expansion factor
based on the 22 turbines. This final model resulted in a point estimate of 0.19 golden eagle
fatalities/year, with an upper 80 th percentile of 0.25 golden eagle fatalities/year. For the 5-year
permit term, this equates to 1.25 golden eagle fatalities, which was rounded up to 2 eagles for
which offsetting compensatory mitigation is required.
Fatality predictions may be adjusted over time in consultation with Service as new data becomes
available based on the results of ongoing monitoring, improvements to the Bayesian model or
other models, best available science, and other factors. If actual take is confirmed to be less than
the predicted level of take in consultation with the Service, PSE would be credited for excess
upfront compensatory mitigation. Fatality predictions, along with results of ongoing monitoring,
will be reviewed at the conclusion of the 5-year permit term in consultation with the Service to
determine whether any adjustments are warranted to support permit renewal.
According to the Service’s 2016 Rule, compensatory mitigation options may include conservation
banking, in-lieu fee (ILF) programs, and other third party mitigation projects or arrangements
determined in coordination with the Service. Power pole modification was selected by PSE as the
preferred mitigation option primarily based on its (1) acceptability by the Service as a form of
mitigation with quantifiable benefits to golden eagles, and (2) the feasibility with which PSE can
implement the mitigation, particularly given PSE’s existing robust APP and the company’s active
role within APLIC. Through careful consideration and coordination with the Service, PSE identified
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three different potential options for completing the power pole retrofit compensatory mitigation
under its ECP. The three options evaluated include retrofitting PSE poles, retrofitting Kittitas
County PUD (KPUD) poles, or providing funding through an In-Lieu Fee (ILF) program.
To calculate the number of poles required for mitigation, we applied the Resource Equivalency
Analysis (REA) (USFWS 2013) for the Wild Horse expansion, resulting in a total of 33 power poles
that would need to be modified for the 5-year permit term given the predicted level of take of 0.25
golden eagles per year, or 2 golden eagles in 5 years, that would require offsetting compensatory
mitigation, assuming the retrofits remain effective for 30 years, and the retrofits are completed
during year one of the permit. If actual take nears the permitted level of take for the 5 -year permit
period, additional measures may be implemented through the adaptive management process.
10.1 Considerations and Proposed Mitigation Methods
When evaluating the three potential mitigation options for implementing power pole retrofits, PSE
considered several factors, including level of electrocution risk of a particular pole or section of
power lines, proximity to Wild Horse (local area vs. eagle management unit), feasibility, timing,
cost, habitat, and longevity of retrofits. When applying the REA and determining the number of
poles PSE is required to retrofit, the results vary due to the timing and longevity of retrofits based
on the method. Pole modifications on PSE poles or through partnership with KPUD can be
completed in Year 1 of the permit, which is consistent with the 33 poles that would require
modification to meet the Service’s requirement for compensatory mitigation under the REA. If
PSE provides funding through the ILF program, based on the 10-year retrofit longevity, and the
ILF program’s 2-year window for implementation resulting in a 3% increase in pole retrofits, PSE
would be required to modify a total of 76 poles. In the event that PSE is unable to implement the
proposed mitigation, PSE will coordinate with the Service and alternative utility(s) to identify and
retrofit poles as needed by applying this same risk assessment methodology, and will adjust the
number of poles based on pole type, retrofit longevity, mitigation credit, and timing of completion
to meet the requirements under the ITP.
Because PSE has not identified areas of high golden eagle electrocution risk within its service
territory, has no documented golden eagle electrocutions or collisions on its system, and did not
have a clear way to demonstrate that retrofitting PSE poles under an ITP would be additive to its
existing program, this option is not considered to be the preferred method for compensatory
mitigation.
In November 2018, the Service notified PSE that an In-Lieu Fee (ILF) program was available (M.
Stuber, pers. comm. 2018). Although the ILF program would be a relatively straight-forward
process for PSE, PSE would have little or no oversight to the poles identified, the utility and
retrofits selected, or the ongoing monitoring and maintenance. Some of the drawbacks to this
method include cost, timing of retrofits (up to two years to complete), the longevity of the retrofits,
and proximity to the project (EMU vs LAP). Additionally, the ILF only incorporates equipment pole
cover-up retrofits into the program and PSE is aware of a number of non-equipment configurations
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in golden eagle habitat that also warrant consideration for pole retrofits and potential reframing or
rebuilding these structures would result in eagle-safe poles in perpetuity or the life of the pole.
Because the Service did not have a mechanism available for providing mitigation funds through
an ILF program when PSE began planning the mitigation for Wild Horse, PSE began discussions
and invested resources into evaluating a partnership with KPUD in early 2018, and has identified
additional benefits of working with KPUD to complete these retrofits; this is PSE’s preferred option
for compensatory mitigation. PSE has a robust Avian Protection Program, is an active APLIC
member, and has the expertise to identify high risk poles, determine appropriate retrofit methods,
conduct monitoring activities in coordination with the PUD, as needed, and in conjunction with
KPUD’s operation and maintenance program. In addition, by retrofitting the poles within the Wild
Horse project area, all electrical distribution and transmission lines at the facility will meet avian-
safe standards. These poles are located in an area identified by the Service as high risk eagle
poles, PSE has documented golden eagle use, and pole retrofits would benefit the local area
population.
In addition, KPUD has expressed interest in developing an Avian Protection Plan, applying the
guidance of PSE avian protection biologists and APLIC 2006 Suggested Practices. This would be
a cost-effective option that could be completed in Year 1 of the ITP, and depending on the types
of retrofits, would be structured to focus on 30-year reframe or rebuild retrofits. Because KPUD
does not currently have a systematic approach to avian protection, the pole modifications under
an agreement with PSE would be additive to their existing efforts, and would provide a framework
and experience for the PUD to address avian protection company-wide.
Under this approach, PSE’s Avian Protection Biologists will provide guidance to KPUD to ensure
that the retrofits are effective in meeting avian-safe standards in accordance with both APLIC
(2006) and PSE’s APP. PSE will coordinate with KPUD, following a similar process as described
in APLIC’s Developing Power Pole Modification Agreements for Compensatory Eagle Mitigation
for Wind Energy Projects (APLIC 2014), to ensure the retrofits are completed correctly,
documenting retrofit accuracy as part of the mitigation program. Additionally, PSE will outline and
coordinate with the Service and KPUD for a retrofit inspection within the timeframe to ensure any
cover-up installations (10-year pole credits) are still in good working order. Upon documentation
that reframed or rebuilt structures (30-year pole credits) reflect the necessary 60 inches horizontal
and 40 inches vertical clearances for distribution voltages, per APLIC (2006), no follow-up
monitoring would apply to these reframed/rebuilt structures. Inspection timing for cover -up on
equipment poles will depend on discussions with the USFWS and KPUD; however, PSE assumes
it may be in the order of a 5- or 10-year monitoring inspection for cover-up applications, with
KPUD committing to maintaining the devices and materials as part of the utility’s standard
operations and maintenance program. This documentation effort would be in accordance with the
Service’s 2013 Eagle Conservation Plan Guidance.
During planning and development for Wild Horse, the design of the facility incorporated numerous
features to avoid or minimize the potential effects on birds, including placing electrical col lection
lines underground wherever feasible to minimize perching locations and electrocution hazards,
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and building power poles to avian-safe standards to minimize risk of electrocution. All PSE 34.5
kV distribution poles within the project area meet the appropriate clearances for preventing eagle
electrocutions using 11-foot cross arms to provide sufficient spacing between conductors.
However, there is an existing KPUD three-phase electrical distribution line within the Wild Horse
project area that does not meet eagle-safe standards. When evaluating mitigation options, these
poles were evaluated for eagle electrocution risk (Dwyer 2014; 2016).
In addition to the 13 poles within the Wild Horse project area, to reach the required number of
poles according to the REA, PSE and KPUD have identified 20 distribution power poles in KPUD’s
service territory in close proximity to Wild Horse that do not meet eagle-safe standards. All 33
poles are located in an area identified by the Service as higher risk to golden eag les based on
hazard, exposure, and vulnerability. Retrofit methods are determined primarily based on existing
pole configuration and equipment, with consideration of other factors such as weather (wind),
retrofit longevity, and right-of-way. Retrofit methods will include a combination of pole removal;
reframing or replacing a structure to achieve adequate spacing of conductors; covering jumper
wires, conductors, and equipment; and other modifications as needed.
We have discussed with KPUD the option to include additional poles beyond the 33 identified in
the ECP REA, as needed, to meet the requirement under the ECP/ITP based on the longevity of
retrofits and mitigation credit term (10-years/30-years).
Although pole reframing or rebuilding often costs more than installing cover-up, achieving the
necessary clearances to allow safe eagle perching on these structures ensures these structures
are bird-safe in perpetuity, does not require maintenance or repair of cover -up materials or
devices, and ensures power pole retrofits provide a viable long-term solution. Although equipment
poles can pose a high electrocution risk to eagles, pole location relative to eagle use is paramount
and as documented by a number of western utilities and outlined in the APLIC 2019 Eagle Forum,
in certain landscapes and habitat types, non-equipment poles also may have high mortality rates
and should be considered when assessing risk and pole retrofit planning.
Eagle mortality data collected by three large western utilities reported the following ratio of eagle
fatalities on non-equipment vs. equipment poles (APLIC 2019 Eagle Forum):
2013-2018: of 47 golden eagle fatalities, 59% to 41%
1981-2018: of 62 golden eagle fatalities, 85% to 15%
2001-2011: of 120,605 poles surveyed
o Bald eagle fatalities, 65% to 35%
o Golden eagle fatalities, 73% to 27%
From statistical data comparisons among the latter two datasets, these data showed pole
configuration, eagle use, and habitats were significant in predicting electrocution risk to eagles.
The data also showed differences in risk for eagles vs. other non-eagle species and between both
eagle species (L. Nielsen, WEST, pers. comm. 2019). Based on these factors, PSE and KPUD
have developed a pole critique strategy to identify at-risk poles to golden eagles within KPUD’s
service territory.
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10.2 Risk Assessment for selecting mitigation poles
PSE is well-versed with retrofit risk assessment and procedures, so this method of mitigation was
selected to meet the requirements of an ITP. To address eagle electrocutions under its APP, PSE
prioritizes areas of concern and develops actions to proactively prevent or mitigate eagle fatalities
through consideration of a variety of biological, engineering, and environmental factors. Since it
has been shown that risk factors for eagles vary somewhat from other bird species (PSE APP
reporting, APLIC 2019 Eagle Forum, APLIC member pers. comm. 2019), PSE is aware of these
differences and has implemented similar risk assessment methodology to identify high-risk poles
to golden eagles under PSE’s Wild Horse ECP. Factors considered include:
The Service’s large-scale modeling power pole densities (Dwyer et al. 2016) and golden
eagle habitat
Dwyer et al., (2014) pole criteria for quantifying risk by structure
APLIC (2006) recommendations for identifying high-risk structures
Existing configuration of poles identified in coordination with Kittitas PUD
PSE’s APP eagle risk assessment considerations, referencing APLIC 2006 and
incorporating anecdotal observations collected since 2000.
o Type/voltage of power line(transmission/distribution)
o Configuration of line/poles and equipment
o Golden eagle habitat
o Nesting habitat and proximity to nest sites
o Known daily movement corridors
o Nearby prey/feeding opportunities
o Perch and nesting substrate availability
o Observed use of electrical facilities
o Historic outage/electrocution data
o Seasonal use by golden eagles and movement patterns
Risk-assessment strategies to assess at-risk poles for eagles and when evaluating the benefit of
retrofitting a specific power pole or section of electrical lines vary, including the Service’s
recommendations and criteria for “qualifying high risk poles;” the APLIC 2006 Suggested
Practices for Reducing Electrocution Risk; and PSE’s APP and avian-safe standards. All of these
methods take into account the pole type and configuration, surrounding habitat, and potential
interaction of eagles with the pole(s) on the landscape.
The Service risk assessment approach primarily uses two strategies, based on large -scale
modeling power pole densities and golden eagle habitat, as presented by Dwyer et al. 2016 for
the Service’s Western Golden Eagle Conservation Team (WGET) and a previous study by Dwyer
et al. 2014 in southern California, using four pole criteria to quantify risk by structure. These
approaches assume that as pole density and pole complexity increase, the risk of electrocution
to eagles also increases. When those risk factors are stratified and overlaid with known habitats
based on land cover types and documented eagle use areas, electrocution risk can be assessed.
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APLIC is a group made up of industry, NGO, and Agency representatives providing state -of-the-
art resources that set the industry standards for protecting bird species from power line
interactions. The guidance on risk assessment provided by APLIC is based on years of studies
and anecdotal information, and is continually re-evaluated as technology changes and improves
over time. PSE has been an active contributing member of APLIC since 2004.
PSE’s APP is based on APLIC recommendations, follows the APP guidelines outlined by APLIC
and the Service (2005), and is tailored to PSE’s service territory with consideration of its electrical
system, eco-region, and local bird species.
PSE’ risk assessment methodologies are consistent with APLIC recommendations, and align with
the Service’s criteria for qualifying high-risk poles. PSE also works closely with the State and
Federal Agency biologists and Service law enforcement personnel to implement the APP across
PSE’s service territory, ensuring transparency and fostering strong partnerships. PSE’s avian
protection program officially began in 2000 in response to the Service’s concerns related to bald
eagle electrocutions. Since the beginning of the program, PSE’s avian biologists have continued
to refine methods for responding to eagle incidents on its electrical system, and identifying high
priority areas to modify consistent with PSE’s avian-safe standards for electrical system design,
which are also consistent with the APLIC 2006 Suggested Practices for Avian Protection. One of
the primary program goals is to systematically reduce the risk of avian electrocution and collision
of PSE’s electrical system. One of the ways this is accomplished is by prioritizing areas of concern
and developing actions to proactively prevent electrocutions through consideration of a variety of
biological, engineering, and environmental factors.
10.3 Schedule
As noted above, PSE began discussions with KPUD in early 2018 to evaluate a partnership for
completing mitigation, and conducted a field visit to look at several areas within KPUD’s Service
Territory to evaluate the risk and potential for eagle interactions with KPUD’s electrical system. In
2019, KPUD provided a list of potential projects, which were evaluated for risk to golden eagles
using the criteria stated above. A site visit occurred on April 25, 2019 to evaluate the
poles/projects in the field and assess the existing pole configurations and the modifications
needed to meet eagle-safe standards, and a follow up inspection was completed by PSE on June
7, 2019 to collect additional pole data. PSE is currently in the process of developing a draft MOU,
Service Agreement, and Contract with KPUD, which would be executed contingent upon and in
anticipation of ITP issuance.
The Service has indicated that they are preparing to publish their Decision to issue an ITP, which
would take effect after a public review and comment period. PSE plans to execute the Contract
upon permit issuance and coordinate with KPUD to complete the mitigation project in 2019. PSE’s
avian protection biologist(s) will coordinate with KPUD’s Engineer to ensure that poles meet
avian-safe standards (APLIC 2006 Suggested Practices, PSE’s APP/Avian-safe Standards), and
will inspect poles upon completion to confirm modifications were completed correctly. In the event
incomplete or inaccurate retrofits are observed, PSE and KPUD will coordinate on what
corrections are needed and when these will be completed.
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10.4 Retrofit Monitoring and Maintenance
The Service recommends/requires monitoring and maintenance of retrofits to ensure that they
remain effective for the duration of the 10-year or 30-year term, depending on the type of retrofit.
For poles retrofitted using reframing, the longevity of the retrofit is considered to be at least 30
years, and would require no monitoring or maintenance once the correct clearances are
documented for submittal to the Service. For poles requiring the installation of equipment covers
or other avian protection devices, the retrofit longevity is estimated at 10 years, and a follow-up
inspection/monitoring will be conducted at a pre-determined timeframe, per communications with
the Service, and maintenance conducted as needed.
As part of the Contract Agreement between PSE and the KPUD, the PUD will be responsible for
maintaining all power poles reframed or retrofitted as part of the utility’s standard Operations and
Maintenance (O&M) program. Part of this responsibility is to ensure cover -up materials and
devices installed on retrofitted poles remain in good working order to ensure the retrofits on
equipment poles are effective to ensure the 10-year retrofit longevity. As stated above, PSE will
inspect the retrofitted poles in years 5 and 10 to ensure the retrofits are in place and operational.
11.0 Adaptive Management
As stated in appendix A of the ECP Guidance, the purpose of adaptive management is to improve
long-term management outcomes by recognizing where key uncertainties impede decision
making, seeking to reduce those uncertainties over time, and applying that learning to subsequent
decisions. Further, in recurrent decisions, there exists the opportunity to reduce that uncertainty
by monitoring outcomes of early actions, and applying that learning to later actions. The three
categories of uncertainty related to the management of eagles identified by the Service in the
ECP Guidance are 1) factors that influence risk of eagle collisions with wind turbines, 2) the
potential of those collisions to affect eagles at the population level, and 3) the efficacy of mitigation
options. The goal of adaptive management in the context of this ECP is to help reduce this
uncertainty over time through the implementation of monitoring and mitigation actions, while
allowing flexibility to adjust these actions over time in consultation with the Service as new data
become available.
11.1 ECP Adaptive Management Process
The ways that an adaptive management approach may result in changes in this ECP over time
include operational factors that may influence collision risk and the level of take, determination of
the appropriate level and types of compensatory mitigation, and implementation of additional
conservation measures. The adaptive management strategy put forth in table 11 -1 and 11-2
below was developed to ensure that golden eagle fatalities remain within the authorized take limits
of an eagle take permit to remain consistent with the goal of no-net loss at both the LAP and EMU
scales, and that bald eagle fatalities remain within the permitted level of take. This would be
achieved by adjusting the monitoring, mitigation, or conservation measures implemented if
estimated take approaches the authorized take, particularly at a higher -than-anticipated rate.
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Conversely, if estimated take is significantly less than the permitted take, the Service, will adjust
the mitigation required for over-mitigating actual take during the permit renewal process.
Thresholds are presented as a tiered progression of potential levels of take that approach the
permitted level of take. Each progressive level, or trigger, warrants increased concern and
potential implementation of additional mitigation or conservation measures as the amount of take
approaches the total permitted take over the 5-year term. Given the 5-year permit term and
renewal process, the collaborative nature of adaptive management could allow for a longer term
approach to managing potential impacts to eagles at Wild Horse in response to cumulative levels
of take during the life of the project. Approaching the first threshold would trigger a meeting with
the Service to provide information related to the fatalities to try to determine a cause or reason for
increased risk (e.g., season, time of day, weather, presence of prey/carrion, fire, or other event).
The second threshold would trigger meeting with the Service, efforts to identify a pattern, cause,
or reason for increased risk, and implementation of additional monitoring if warranted. The third
threshold would trigger action at the project to offset or reduce risk of additional fatalities to ensure
that take remains within the permitted level. These actions may include the items listed in section
11.2, such as changes in site management (prey species or food source, nest management, etc.),
camera or drone monitoring, adjusting turbine operations, or other conservation measures.
Table 11-1. Summary of stepwise adaptive management process for eagle take at the Wild Horse
Wind Energy Facility. Based on a permitted take rate averaging 1.72 GOEA/year and 0.53 BAEA/year totaling 9 GOEA eagles and 3 BAEA over a 5-year permit period. Assumes g-values of 0.45 in years 1-3 and 0.12 in years 4-5.
Trigger or Threshold Conservation Measures
Trigger
1
1 GOEA fatality found
Meet w ith the Service and assess eagle fatalities
to determine if cause or risk factor can be
identif ied
Take is w ithin the permitted level and fully
mitigated.
Assess g-value based on f irst year SEEF/Carcass
Persistence. If g-value meets criteria of Table X2,
then move to Table X2 for alternate triggers and
measures.
Trigger
2
> 2 GOEA fatalities
found during the 3-
year operational
monitoring period
1 BAEA fatality
found over the 3-
year operational
monitoring period
Meet w ith the Service to assess eagle fatalities to
determine if cause or risk factor can be identif ied,
and w hether specif ic action is w arranted.
Implement an additional year of formal monitoring
if w arranted and refine protocols as needed in
consultation w ith the Service.
Take is w ithin the permitted level and fully
mitigated.
Trigger
3
> 2 GOEA fatalities
found over a 2-year
period
OR
> 3 GOEA fatalities
found during the
permit term (5 years)
2 BAEA fatalities
found during the
permit term.
If this trigger is reached near the end of the permit
term (> 2 GOEA in Y4/> 3 GOEA in Y5), meet w ith
the Service to determine if cause or risk factor can
be identif ied, and w hether specif ic action is
w arranted.
If this trigger is reached prior to Y4, consult w ith
the Service to determine conservation measures
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Table 11-1. Summary of stepwise adaptive management process for eagle take at the Wild Horse Wind Energy Facility. Based on a permitted take rate averaging 1.72 GOEA/year and 0.53 BAEA/year totaling 9 GOEA eagles and 3 BAEA over a 5-year permit period. Assumes g-values of 0.45 in years 1-3 and 0.12 in years 4-5.
Trigger or Threshold Conservation Measures
to be implemented to reduce the rate of take to
permitted levels. Additional measures may
include:
o Change in site management (prey
species or food source, nest
management, etc.)
o Implement biological monitoring,
detection/deterrent measures or
operational changes at specif ic turbines if
w arranted
Take is potentially still w ithin the permitted level
but may w arrant additional mitigation.
Table 11-2. Summary of stepwise adaptive management process for eagle take at the Wild Horse Wind Energy Facility. Based on a permitted take rate averaging 1.72 GOEA/year and 0.53 BAEA/year totaling 9 GOEA eagles and 3 BAEA over a 5-year permit period. Assumes g-values of 0.7 in years 2-3 and 0.12 in years 4-5.
Trigger or Threshold Conservation Measures
Trigger
1
2 GOEA fatalities
found over the 3-year operational
monitoring period
Meet w ith the Service and assess eagle fatalities
to determine if cause or risk factor can be
identif ied
Take is w ithin the permitted level and fully
mitigated.
Trigger
2
3 GOEA fatalities
found during the 3-year operational
monitoring period
1 BAEA fatality found
over the 3-year
operational monitoring
period
Meet w ith the Service to assess eagle fatalities to
determine if cause or risk factor can be identif ied,
and w hether specif ic action is w arranted.
Implement an additional year of formal monitoring
if w arranted and refine protocols as needed in
consultation w ith the Service.
Take is w ithin the permitted level and fully
mitigated.
Trigger
3
> 3 GOEA fatalities found over a 2-year
operational
monitoring period
OR
4 GOEA fatalities
found during the
permit term (5 years)
2 BAEA fatalities found
during the permit term.
If this trigger is reached near the end of the permit
term (> 2 GOEA in Y4/> 3 GOEA in Y5), meet w ith
the Service to determine if cause or risk factor can
be identif ied, and w hether specif ic action is
w arranted.
If this trigger is reached prior to Y4, consult w ith
the Service to determine conservation measures
to be implemented to reduce the rate of take to
permitted levels. Additional measures may
include:
o Change in site management (prey species or food
source, nest management, etc.)
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Table 11-2. Summary of stepwise adaptive management process for eagle take at the Wild Horse Wind Energy Facility. Based on a permitted take rate averaging 1.72 GOEA/year and 0.53 BAEA/year totaling 9 GOEA eagles and 3 BAEA over a 5-year permit period. Assumes g-values of 0.7 in years 2-3 and 0.12 in years 4-5.
Trigger or Threshold Conservation Measures
o Implement biological monitoring,
detection/deterrent measures or operational
changes at specif ic turbines if w arranted
Take is potentially still w ithin the permitted level
but may w arrant additional mitigation.
11.2 Adaptive Management Conservation Measures
If estimated level of eagle take nears or exceeds the permitted level of take, or the level of take
that can be sustained to maintain stable or increasing eagle populations is significantly reduced
over time, and PSE determines through consultation with the Service that additional conservation
measures are warranted to preserve the stability of local area eagle populations, the following
conservation measures may be implemented. Additionally, for fatalities associated with the
original project (not requiring offsetting compensatory mitigation) may warrant a response from
PSE if estimated fatalities approach the permitted level of take, or if conditions suggesting higher
than anticipated risk, the following conservation measures may be implemented.
Adjust turbine operations
Use of automated detection devices (e.g., cameras, radar, etc.) or biological monitors to
monitor eagle behavior
Modify monitoring protocol, determine whether additional studies are warranted
Nest management if new eagle nests are identified in the project area
Contributions to raptor rehabilitation facilities
Partnership with WDFW or NGOs to support programs that reduce eagle mortality, such
as lead abatement or carcass removal programs
Provide funding for studies that aim to better understand spatial and temporal behavior of
eagles in the project vicinity, such as telemetry studies or nesting surveys
11.2.1 Lead Abatement
PSE may have an opportunity to partner with WDFW to address the issue of eagle lead
contamination to try to reduce toxic lead that is available to raptors through increased outreach
and education and support of WDFW efforts. WDFW is currently researching various aspects of
eagle lead contamination, such as baseline sampling of lead contaminants, diet studies, and
experimental placement of deer offal to examine eagle feeding rates and potential exposure. In
order to increase emphasis and public awareness on this issue, continued research along with
increased documentation of lead levels in the nesting population, prey sources, and potentially
experimental studies to determine efficacy of lead abatement is needed (J. Watson, 2014). PSE’s
role may involve providing funding for WDFW research of this issue, as well as hunter outreach
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and education, and even distributing non-lead shot to hunters using project lands to further reduce
the potential for eagle lead contamination.
11.2.2 Golden Eagle Telemetry Studies
The WDFW recently conducted golden eagle telemetry studies to characterize their spatial use
of the landscape. The Western Golden Eagle Team, which was organized by the Service, is
studying immature golden eagle movements and survival. The group is also proposing to examine
spatial associations between immature eagles and resident adult territories along the Tucannon
River and Asotin Creek drainages in southeast Washington (J. Watson, 2014b). This would
provide an opportunity for PSE to partner with the Service and WDFW to conduct research and
obtain data related to golden eagle age and spatial use in the general vicinity of PSE’s wind
facilities, which may help determine management strategies at these and other wind facilities in
the region.
11.2.3 Partnership with Blue Mountain Wildlife Rehabilitation
Blue Mountain is the largest raptor rehabilitation center in the Northwest serving a large
geographic area including eastern Oregon and south eastern and central Washington. Blue
Mountain has treated over 5,000 injured raptors since its inception in 1990, approximately half
(48%) of which were released. Thirty-six golden eagles and 36 bald eagles were admitted to Blue
Mountain between 2010 and 2017. Of those, six golden eagles and ten bald eagles were released,
however, the survival rate of released eagles is unknown, and would likely vary due to a number
of factors. Blue Mountain has been testing blood levels since 1999, finding elevated levels in
nearly three-quarters of eagles tested.
For nearly 20 years, Blue Mountain has been a leader in the campaign to increase awareness of
the dangers of ingested lead poisoning in raptors and the benefits of using non-lead ammunition.
In addition to local school programs, Blue Mountain has provided outreach and education to many
entities, including Blue Mountain Land Trust program, Oregon Wildlife Society, Winter Birds
Program, Hanford Reach Education Center, Audubon, and other public events. PSE currently
provides funding to Blue Mountain Wildlife Rehabilitation (Blue Mountain), and partners with Blue
Mountain to provide educational opportunities for local elementary schools related to birds and
bird protection.
In addition to continued annual support to Blue Mountain Wildlife Rehabilitation, PSE will consider
providing additional funding as a potential conservation measure under the adaptive management
process. This additional funding would be used to support one or more of the following:
Provide tracking devices for eagles prior to release
Improve the facility’s ability to conduct lead testing of raptors
Support educational programs and resources
Provide consultation services to wind facilities in the area
Improve their facilities to better care for injured eagles and other raptors rehabilitated
throughout the region
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12.0 Reporting
The purpose of reporting under the ECP is to provide regular updates to the Service on the
implementation of the measures outlined in this ECP. PSE has existing reporting procedures in
place under its SPUT permit and SCA for reporting avian and bat fatalities to both OLE and
RMBPO, which are described in section 12.1. In addition to incidental reporting procedures, PSE
is proposing to submit reports annually to the Service documenting activities completed the
previous calendar year under the ECP. At the end of the 5 year permit term, a 5 year
comprehensive report would be compiled to summarize actions taken over the 5 year permit term
in preparation for permit reapplication (section 12.2).
12.1 SPUT Permit Reporting
The Service recommends that the mortalities of birds protected under BGEPA, MBTA, and ESA
be reported. In accordance with PSE’s SPUT permit reporting conditions, Avian Protection Plan
reporting procedures, and the Wild Horse SCA, all dead and injured birds found at Wild Horse are
reported to State and Federal Wildlife Agencies. PSE employees and subcontractors have a
responsibility to comply with all environmental laws and regulat ions, and are trained annually to
follow procedures outlined in the WIRHS when responding to dead or injured birds that are found
incidentally in the project area to ensure proper response and documentation of each fatality.
Any incident involving a state- or federally-listed threatened or endangered species or a bald or
golden eagle is reported to the Service and WDFW within 24 hours of identification, or the next
business day if found on a weekend or holiday.
Primary contacts for agency personnel include:
Eric Marek, USFWS OLE
Manisa Kung, USFWS OLE
Jennifer Miller, USFWS RMBPO
Mandy Lawrence, USFWS RMBPO
Stephen Lewis, USFWS
Mike Ritter, WDFW
All MBTA-protected species and bats found at Wild Horse are documented using the WIRHS, and
data are compiled annually for submittal to the USFWS Regional Migratory Bird Permit Office as
a condition of PSE’s SPUT permit. In years when formal monitoring studies are completed, all
MBTA species found during surveys are also included in PSE’s annual report to the Service.
12.2 ECP Annual Reporting
Reporting on the implementation of this ECP will be consistent with the Service’s ECP Guidance.
PSE will prepare an annual report that describes eagle management activities that occurred at
Wild Horse during the previous January through December. Each report will include conservation
measures, monitoring methods and results, compensatory mitigation activities, any additional
study protocols and results, and other incidental wildlife observations or fatalities that occurred
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during the reporting period. At the end of the 5-year permit period, a comprehensive report will be
compiled to prepare for permit renewal. These reports will facilitate consultation with the Service
and will be used to review and compare the estimated and actual take, measures implemented
during the 5-year permit term, and identify any adjustments needed to the measures outlined in
the ECP prior to permit renewal.
The report format will provide a summary of activities implemented during the preceding year,
including:
Study protocols and results
Formal monitoring activities, protocol, and results in pertinent years
Incidental monitoring activities, procedures, and results
Any eagle fatalities identified and related information
Conservation measures
Compensatory mitigation measures
Comparison of estimated take to actual observed take
Consultation with the Service and other wildlife agencies
New best available science or data
Adaptive management measures
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Wild Horse Wind Energy Facility Revised DRAFT - Eagle Conservation Plan
Appendix A: Elevation, Slope, and Aspect Characteristics of Constructed Turbines at the Wind
Energy Facility
Wild Horse Wind Energy Facility Revised DRAFT - Eagle Conservation Plan
Appendix A. Elevation, slope, and aspect characteristics of constructed turbines at the Wind Energy Facility.
Area Turbine Aspect (Degrees) Slope (Degrees)
Expansion R01 9 10 Expansion R02 292 2 Expansion R03 291 1 Expansion R04 188 8 Expansion R05 108 3 Expansion R06 274 3 Expansion R07 244 1 Expansion R08 230 2 Expansion R09 191 7 Expansion R10 162 5 Expansion R11 57 5 Expansion R12 104 3 Expansion R13 104 1 Expansion S1 333 3 Expansion S2 281 3 Expansion S3 285 3 Expansion S4 265 1 Expansion T1 3 10 Expansion T2 121 5 Expansion T3 128 2 Expansion U1 311 0 Expansion U2 214 3 Phase 1 A1 188 12 Phase 1 A2 190 12 Phase 1 A3 123 4 Phase 1 A4 166 7 Phase 1 A5 175 14 Phase 1 A6 191 11 Phase 1 A7 200 7 Phase 1 A8 181 15 Phase 1 B1 225 14 Phase 1 B2 182 18 Phase 1 C1 47 2 Phase 1 C2 65 14 Phase 1 C3 117 4 Phase 1 C4 300 1 Phase 1 C5 174 3 Phase 1 C6 110 4 Phase 1 C7 78 5 Phase 1 C8 282 3 Phase 1 C9 194 22 Phase 1 C10 123 2 Phase 1 C11 174 10 Phase 1 C12 170 7 Phase 1 C13 208 2 Phase 1 C14 95 4 Phase 1 C15 175 5 Phase 1 C16 75 1 Phase 1 C17 219 7 Phase 1 C18 190 5 Phase 1 D1 45 8 Phase 1 D2 123 8 Phase 1 D3 44 7
Wild Horse Wind Energy Facility Revised DRAFT - Eagle Conservation Plan
Appendix A. Elevation, slope, and aspect characteristics of constructed turbines at the Wind Energy Facility.
Area Turbine Aspect (Degrees) Slope (Degrees) Phase 1 D4 57 3 Phase 1 D5 313 2 Phase 1 D6 118 1 Phase 1 D7 359 6 Phase 1 D8 333 3 Phase 1 D9 157 5 Phase 1 D10 192 5 Phase 1 D11 72 0 Phase 1 D12 105 2 Phase 1 D13 171 3 Phase 1 D14 12 10 Phase 1 D15 101 6 Phase 1 D16 116 7 Phase 1 D17 161 8 Phase 1 D18 173 9 Phase 1 D19 194 7 Phase 1 D20 105 4 Phase 1 D21 124 4 Phase 1 D22 299 5 Phase 1 D23 261 6 Phase 1 D24 102 5 Phase 1 D25 289 2 Phase 1 D26 350 2 Phase 1 D27 309 1 Phase 1 D28 311 5 Phase 1 D29 178 20 Phase 1 D30 67 3 Phase 1 D31 99 5 Phase 1 D32 118 5 Phase 1 D33 144 2 Phase 1 D34 281 2 Phase 1 D35 355 2 Phase 1 D36 153 0 Phase 1 D37 165 8 Phase 1 E1 5 16 Phase 1 E2 313 5 Phase 1 E3 333 10 Phase 1 E4 339 3 Phase 1 E5 202 1 Phase 1 E6 112 1 Phase 1 E7 150 1 Phase 1 E8 173 3 Phase 1 E9 185 4 Phase 1 E10 180 2 Phase 1 E11 200 0 Phase 1 F1 337 5 Phase 1 F2 12 6 Phase 1 F3 12 6 Phase 1 F4 355 1 Phase 1 F5 152 2 Phase 1 G1 21 10 Phase 1 G2 77 5 Phase 1 G3 56 9
Wild Horse Wind Energy Facility Revised DRAFT - Eagle Conservation Plan
Appendix A. Elevation, slope, and aspect characteristics of constructed turbines at the Wind Energy Facility.
Area Turbine Aspect (Degrees) Slope (Degrees) Phase 1 G4 23 6 Phase 1 G5 191 4 Phase 1 G6 197 9 Phase 1 G7 181 11 Phase 1 H1 354 17 Phase 1 H2 97 2 Phase 1 H3 172 15 Phase 1 I1 25 12 Phase 1 I2 204 1 Phase 1 J1 37 5 Phase 1 J2 88 8 Phase 1 J3 97 6 Phase 1 J4 109 1 Phase 1 K1 6 8 Phase 1 K2 20 2 Phase 1 K3 104 2 Phase 1 K4 97 2 Phase 1 K5 94 0 Phase 1 K6 210 4 Phase 1 L1 71 4 Phase 1 L2 187 8 Phase 1 L3 118 2 Phase 1 L4 163 3 Phase 1 M1 355 4 Phase 1 M2 289 1 Phase 1 M3 193 1 Phase 1 M4 175 2 Phase 1 M5 100 1 Phase 1 M6 236 0 Phase 1 N1 355 4 Phase 1 N2 75 4 Phase 1 N3 100 10 Phase 1 N4 149 6 Phase 1 O1 329 6 Phase 1 O2 97 1 Phase 1 O3 158 4 Phase 1 O4 125 8 Phase 1 P1 344 1 Phase 1 P2 173 7 Phase 1 Q1 245 4 Phase 1 Q2 191 6 Phase 1 Q3 185 7 Phase 1 Q4 107 1 Phase 1 Q5 190 11
Wild Horse Wind Energy Facility Revised DRAFT - Eagle Conservation Plan
Appendix B: Federal Fish and Wildlife Special Purpose Utility (SPUT) Permit and Renewal
Application Form
Wild Horse Wind Energy Facility Revised DRAFT - Eagle Conservation Plan
Wild Horse Wind Energy Facility Revised DRAFT - Eagle Conservation Plan
Wild Horse Wind Energy Facility Revised DRAFT - Eagle Conservation Plan
Wild Horse Wind Energy Facility Revised DRAFT - Eagle Conservation Plan
Wild Horse Wind Energy Facility Revised DRAFT - Eagle Conservation Plan
Wild Horse Wind Energy Facility Revised DRAFT - Eagle Conservation Plan
Wild Horse Wind Energy Facility Revised DRAFT - Eagle Conservation Plan
Wild Horse Wind Energy Facility Revised DRAFT - Eagle Conservation Plan
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