conservation biogeography of a rare prairie grouse · conservation biogeography of a rare prairie...
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Conservation biogeography
of a rare prairie grouse
Michael A. Patten
University of Oklahoma Oklahoma Biological Survey, Department of Biology, and
Sutton Avian Research Center
use of biogeographical techniques and principles to guide conservation planning
for example, island biogeography • species-area relationships
• degree of isolation
areas of endemism
patterns of species richness
trait variation across space
can consider the past and future, too
Conservation Biogeography
lower panel: Smith-Patten and Patten (2015, Biotropica 47:128–135)
Examples include: o forecasts
o reserve selection
o invasive species
Single species or entire communities.
Does one size fit all?
The Lesser Prairie-Chicken
photos by Noppadol Paothong
o a medium-sized grouse endemic to southern shortgrass and mixed grass prairies
o endemic to the south-central United States (i.e., it is found nowhere else, and never has been)
Lekking
o lek mating system
o as with other open-country grouse, males gather communally to display to females . . . and to squabble with other males
photos by Greg W. Lasley, Noppadol Paothong, and Joel Sartore
o the goal is to lure a female to mate . . . at which point the male continues to display and the female heads off to
• build a nest
• guard her eggs
• (with luck) raise her young
Data Collection
Sample Sizes
• 898 radiotagged birds (>1000 banded) 550 in Oklahoma, 1999–2014 348 in New Mexico, 2000–2005
• 267 nests 142 in Oklahoma, 1999–2014 125 in New Mexico, 2000–2005
• >60,000 individual tracking locations
• ~18,000 vegetation samples 6483 vegetation and general cover transects 10488 “cone of vulnerability” and microclimate 737 1-m2 grass and forb plots
The Data
o survivorship and cause of mortality
o movements (and home range)
o habitat use (including for leks and broods) – woody vegetation – grasses and forbs – “cone of vulnerability” – microclimate
o nest placement
o demography (clutch size, nest success, reproductive effort, etc.)
o mitochondrial DNA and microsatellites
o nutrition (blood screening)
Southern Shortgrass Prairie
Habitat Loss
Samson et al. (2004, Wildlife Society Bulletin 32:6–15)
Population Decline
• total world population numbers 20,000–35,000
• population has declined by >90% in the past century
trend from Hagen et al. (2009, Journal of Wildlife Management 73:1325–1332)
The U.S. Endangered Species Act
almost exactly a year ago today . . .
the species was listed as threatened under the U.S. Endangered Species Act
Controversy
Capitol Hill Outsider (2014)
Ecoregions
Ecoregions
10.4 birds / km2
23.3 birds / km2
13.0 birds / km2
18.1 birds / km2
Ecoregions
plot from Oyler-McCance, DeYoung, Hagen, Johnson, Larsson, and Patten (in prep., targeted for Conservation Genetics)
STRUCTURE plot for 13 microsatellite loci
Selectivity
Patten et al. (2005, Journal of Wildlife Management 69:1270–1278)
Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep
Me
an
Exp
osu
re A
ngle
(o)
0
10
20
30
40occupied
random
2003 2004
Microclimate
Patten et al. (2005, Journal of Wildlife Management 69:1270–1278)
Larsson et al. (2013, Southwestern Naturalist 58:135–149)
Predator Avoidance
Larsson et al. (2013, Southwestern Naturalist 58:135–149)
summer '03 autumn '03 winter '03/04 spring '04 summer '04 autumn '04
Mean A
ppare
nt T
em
pera
ture
(oC
)
0
5
10
15
20
25
30
Mean E
xposure
Angle
(o)
4
6
8
10
12
14
16
18
20depredations
angle
temperature
Woody Vegetation and Adult Survival
Days
0 200 400 600 800 1000
Pro
ba
bili
ty o
f S
urv
iva
l
0.0
0.2
0.4
0.6
0.8
1.0
shrub cover <10%
shrub cover 10–20%
shrub cover >20%
Patten et al. (2005, Journal of Wildlife Management 69:1270–1278)
Too Many Shrubs
cedar photos by Donald H. Wolfe
Loss of Shrub Cover
Sagebrush Steppe Treatment Evaluation Project <http://www.sagestep.org/>
Too Few Shrubs
Patten and Kelly (2010, Ecological Applications 20:2148–2156)
Mean Shrub Cover (%)
5 10 15 20 25 30
Num
ber
of N
ests
0
2
4
6
8
10 tebuthiuron
untreated
Solutions
The Prairie Has Changed
Pruett et al. (2009, BioScience 59:257–262)
The Future
photos by Donald H. Wolfe
Avoidance of Highways
Pruett et al. (2009, Conservation Biology 23:1253–1259)
Pruett et al. (2009, Conservation Biology 23:1253–1259)
Avoidance of Power Lines
Pruett et al. (2009, Conservation Biology 23:1253–1259)
Highways + Power Lines
Pruett et al. (2009, Conservation Biology 23:1253–1259)
< 100 m 100–500 m
Lesser Prairie-Chicken
transmission line 6 (88–129) 156 (398–471)
Highway 412 24 (25–48) 182 (125–165)
Highway 283 20 (135–181) 166 (586–674)
Greater Prairie-Chicken
transmission line 0 (16–35) 5 (83–121)
no evidence of avoidance > 500 m from any feature
Avoidance Behavior*
*Behaviour
meters (± SE)
0 200 400 600 800 1000 1200 1400
oil or gas wellheads
center-pivot fields
unimproved roads
improved roads
roads (any type)
buildings
transmission lines
nests
birds
data from Robel et al. (2004, Transactions of the N. Am. Wildlife Natural Resources Conference 69:251–266)
Other Manmade Features
Nest Placement
data from Pitman et al. (2005, Journal of Wildlife Management 69:1259–1269) meters
0 500 1000 1500 2000
tranmission line
wellhead
building
unimproved road
improved road
center-pivot
transmission line
And so on . . .
Winder et al. (2014, Ecosphere 5[1]:3)
Hagen et al. (2011, Studies in Avian Biology 39:63–75
Planning Tools
Correlations
Truism 1: Where there is a powerline or a road there typically is a fence.
Spellerberg (1998, Global Ecology and Biogeography Letters 7:317–333)
Truism 2: And where there is a fence there typically is:
o habitat loss o livestock o woody vegetation encroachment
Fence Collisions
Fence Collisions
Determining Cause of Death
o radio-transmitters on our Lesser Prairie-Chickens equipped with a mortality switch
o recovered carcasses are examined to determine one of four causes of death: o raptor kill o mammal kill o collision — fence, power line, or car o other (or unknown) — this category has included, for
example, drowning in a stock tank
o note that collisions are associated with habitat fragmentation
Mortality Cause
proportion of mortalities
0.0 0.1 0.2 0.3 0.4 0.5
raptor
mammal
fence
powerline
vehicle New Mexico
Oklahoma
data from Wolfe et al. (2007, Wildlife Biology 13[supp. 1]:95–104)
n = 260
Days
0 200 400 600 800 1000
Pro
ba
bili
ty o
f S
urv
iva
l
0.0
0.2
0.4
0.6
0.8
1.0
New Mexico
Oklahoma
Days
0 200 400 600 800
Pro
ba
bili
ty o
f S
urv
iva
l
0.0
0.2
0.4
0.6
0.8
1.0
New Mexico
Oklahoma
Survival by Sex
♂
♀
Patten et al. (2005, Evolutionary Ecology Research 7:235–249)
Month
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Pra
irie
-chic
ke
n k
ills d
ue
to
pre
da
tio
n
5
10
15
20
25
Pro
po
rtio
n o
f m
ale
s k
ille
d
4
6
8
10
12
14
16
18
predation
male mortality
Month
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Pra
irie
-chic
ke
n k
ills d
ue
to
co
llisio
ns
0
3
6
9
12
15
18
Pro
po
rtio
n o
f fe
ma
les k
ille
d
0
6
12
18
24
30
36collisions
female mortality
♀♀ and collisions
♂♂ and predation
Patten et al. (2005, Evolutionary Ecology Research 7:235–249)
Life-history Evolution
o Lifetime reproductive value o a species-specific trait
o roughly constant among populations
o Trade-offs o both fecundity and lifespan contribute
o r selection vs. K selection
o common in birds
Predictions! Higher mortality of Oklahoma ♀♀ o larger clutch sizes
o more fledglings
o attempt more nests in a season
Fecundity
New Mexico Oklahoma
fre
que
ncy
0
2
4
6
8
10
12 clutch size
fledglings
adapted from Patten et al. (2005, Evolutionary Ecology Research 7:235–249)
Mean nest attempts
/ year (± SE) 1.07 ± 0.04 1.55 ± 0.11
Proportion re-nesting
in same year 0.15 0.94
Fragmentation
Patten et al. (2005, Evolutionary Ecology Research 7:235–249)
New Mexico Oklahoma o mean parcel size ~1300 ha ~180 ha o roads / 10-km2 8.0 ± 2.3 14.5 ± 1.7 o fencing sections* ¼-sections
o land tenure differences have a historical basis (Homestead
Act vs. Spanish Land Grant)
o land tenure in the Texas Panhandle is much more like that in Oklahoma than in New Mexico
Patten et al. (2005, Evolutionary Ecology Research 7:235–249)
Land Tenure
*1 section ≈ 260 ha and is 1.6 km per side
Plasticity?
Cumulative Precipitation (cm)
0 2 4 6 8 10 12 14 16
Me
an C
lutc
h S
ize
7
8
9
10
11
12
13 New Mexico
Oklahoma2002 (7)
2003 (4)
2000 (5)
2001 (7)
2001 (15)
1999 (2)
2002 (25)
2000 (2)
2003 (13)
Patten et al. (2005, Evolutionary Ecology Research 7:235–249)
Nutrition?
retinol (vitamin A)
0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0
clu
tch
siz
e
8
9
10
11
12
13
vitamin E
0 2 4 6 8 10
lutein
0 2 4 6 8
clu
tch
siz
e
8
9
10
11
12
13
zeaxanthin
0 2 4 6
canthaxanthin
0.0 0.5 1.0 1.5 2.0
clu
tch
siz
e
8
9
10
11
12
13
xanthophylls
0 2 4 6 8 10 12 14 16
Only vitamin A (as retinol) is correlated with clutch size . . . but in the “wrong” direction:
New Mexico ♀♀ have higher levels of vitamin A but lay smaller clutches.
Sutton Avian Research Center unpubl. data
o ♀♀ in Oklahoma die from fence collision far more often than do ♀♀ in New Mexico
o more roads more fences more collisions (ultimately a result of historic land parceling)
o survivorship in Oklahoma has (apparently) selected for clutch size and re-nesting rate
o larger clutches do not appear to be the result of variation in rainfall or nutrition
In summary . . .
The fate of the mixed
grass prairie population?
Years
0 5 10 15 20 25 30
Pro
ba
bili
ty o
f E
xtin
ctio
n
0.0
0.2
0.4
0.6
0.8
1.0
2005 Patten et al. (2005, Evolutionary Ecology Research 7:235–249)
2022
Year
2004 2006 2008 2010 2012 2014 2016 2018
Po
pula
tio
n S
ize
0
500
1000
1500
2000
2500
Oklahoma
New Mexico
100% of simulations forecast a population crash in Oklahoma, yielding
Management Strategies
Option 1: Increase fecundity
Requires clutch sizes approaching 30 (!).
Requires 3 successful nests / year.
i.e., reproductive output must double.
Pruett et al. (2011, Conservation Genetics 12:1205–1214)
Option 2: Reduce ♀ mortality
At current Ne, raising adult ♀ survivorship to the level of that elsewhere (e.g., New Mexico) would ensure population persistence.
Management Strategies
Option 1: Increase fecundity
Requires clutch sizes approaching 30 (!).
Requires 3 successful nests / year.
i.e., reproductive output must double.
Pruett et al. (2011, Conservation Genetics 12:1205–1214)
Option 2: Reduce ♀ mortality
At current Ne, raising adult ♀ survivorship to the level of that elsewhere (e.g., New Mexico) would ensure population persistence.
Reducing Mortality
see Baines and Andrew (2003, Biological Conservation 110:169–176)
Reducing mortality
Wolfe et al. (2009, Ecological Restoration 27:141–143)
Fence marking
Does marking work?
efficacy not assessed fully, but . . . all except one collision 2007–2014 have been along unmarked fences!
Stevens et al. (2012, Wildlife Society Bulletin 27:141–143)
Winder et al. (2015, Ecosphere in press)
o kernel HR estimators
o land cover from aerial photos & GIS layers
o software estimates of habitat proportions & edge
Extent of Contiguous Habitat (ha)
0 10000 20000 30000 40000
Ho
me
Ra
nge
(ha
)
500
1000
1500
2000
2500
Patten et al. (2011, Studies in Avian Biology 39:51–62)
Wrapping Up
One size does not fit all!
A single, all-encompassing plan that would benefit each Lesser Prairie-Chicken population in the same way cannot be devised.
Instead, we must consider geographic variation among populations to guide management and conservation.
Thank You Save the prairie chicken!