bat report of land near mitford bat...
TRANSCRIPT
BAT SURVEY
March 2015
BAT REPORT OF LAND NEAR MITFORD
REPORT NO1
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Principal Contact: Dr Tony Martin BSc PhD MLI MCIEEM Director [email protected]
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Client Revision Status Date Author Proof Read Checked
Signet
Planning
R01 Final 6/3/2015 ADM/JA SW ADM
Job No. 3464
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CONTENTS
SUMMARY .............................................................................................................................. 4
INTRODUCTION ..................................................................................................................... 6
A.1 Background to development ...................................................................................... 6 A.2 Personnel .................................................................................................................. 7 A.3 Objectives of study ..................................................................................................... 8
B RELEVANT LEGISLATION AND PLANNING CONTEXT ................................................ 9
B.1 National Planning Policy Framework .......................................................................... 9 B.2 Protected species legislation ...................................................................................... 9
C SURVEY AREA AND METHODOLOGY ........................................................................ 11
C.1 Survey area ............................................................................................................. 11 C.2 Methodology ............................................................................................................ 12
C.2.1 Desktop study ................................................................................................................... 12 C.2.2 Survey equipment ............................................................................................................ 12 C.2.3 Phase 1 habitats............................................................................................................... 12 C.2.4 Timing ............................................................................................................................... 14 C.2.5 Weather conditions........................................................................................................... 15
D RESULTS ....................................................................................................................... 16
D.1 Desktop study .......................................................................................................... 16 D.1.1 Pre-existing information ................................................................................................... 16 D.1.2 Consultation ..................................................................................................................... 16 D.1.3 Bat risk assessment ......................................................................................................... 17
D.2 Field survey ............................................................................................................. 18 D.2.1 Habitats ............................................................................................................................ 18 D.2.2 Trees ................................................................................................................................ 18 D.2.3 Activity surveys ................................................................................................................. 19 D.2.4 2013 ................................................................................................................................. 19 D.2.5 2014 ................................................................................................................................. 25
D.2.5.1 Transect Surveys ......................................................................................................... 25 D.2.5.2 Static Monitoring........................................................................................................... 31 D.2.5.3 2014 Overview: ............................................................................................................ 33
E ASSESSMENT ............................................................................................................... 34
E.1 Assessment of survey findings ................................................................................. 35 E.2 Impacts .................................................................................................................... 35 E.3 Constraints .............................................................................................................. 36
F MITIGATION AND RECOMMENDATIONS .................................................................... 36
F.1 Further survey .......................................................................................................... 36 F.2 Mitigation requirements ............................................................................................ 36
G APPENDICES ................................................................................................................ 39
G.1 Appendix 1: Stationary Data .................................................................................... 39 G.2 Appendix 2: BAT ECOLOGY ................................................................................... 44
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SUMMARY
E3 Ecology Ltd was commissioned by Signet Planning LLP to undertake bat surveys of land east of Mitford, in August 2013 and the survey season of 2014. Consultation with ERIC NE indicated that the following bat species have previously been recorded within a 2km radius of the site: Daubenton’s bat, Natterer’s bat, noctule, common pipistrelle, soprano pipistrelle and brown long-eared bat. Survey work was undertaken in August and September 2013 which suggested that habitats within the site were of low value for bats, requiring seasonal surveys, and was continued in the 2014 survey season to provide data from spring, summer and autumn across the two years. Survey comprised a daytime risk assessment of the trees on site as part of the extended phase 1 survey, 10 dusk bat transect surveys and static monitoring. The site is situated in an area dominated by arable farmland and intensively managed grassland. The urban residential edge of the town of Morpeth lies to the east, with the A1 directly adjacent to the site on the western boundary. Overall, the habitats present within the local area would suggest that the potential of bats of roosting, foraging and commuting in the local area is moderate to high. However, there are multiple alternate roost sites for bats such as pipistrelles, which may use the housing to the east for this purpose. The 2014 surveys highlighted a peak in activity during the autumn period, with a shift in site usage throughout the year. Spring suggested a low value site for bats, summer a medium value site and autumn a higher value site. Overall pass rates were moderate with a maximum of 43.6 passes per hour, with the majority of activity identified as common and soprano pipistrelle. The site value was increased by the diversity of species recorded, which included; Myotis sp., common and soprano pipistrelle, whiskered, Brandt’s or Alcathoe’s, noctule, brown long eared, Daubenton’s and Natterer’s. First record timings are suggested to indicate the presence of soprano and common pipistrelle and potentially Myotis sp. maternity roosts nearby. Dusk transect surveys indicated that the site is used primarily by common and soprano pipistrelle bats, which use the hedgerows at field boundaries as key commuting and foraging routes. Other species were occasionally recorded including Daubenton’s, noctule, whiskered, Brandt’s or Alcathoe’s and Myotis sp. Early activity in the north of the site suggests that roosts may be present within the housing to the east of the site, whilst activity to the south of the site suggests that tree roosts may be present off-site near here, possibly supporting soprano pipistrelle and whiskered, Brandt’s or Alcathoe’s bats. Survey work, carried out by AECOM, for the adjacent bypass concluded that some tree roosting bats were present within the site, and this work confirms that seasonal tree roosts used by small numbers of bats, particularly in the autumn, are present. It is concluded that the site is of local value to bats but part of a wider network of habitats of district value, primarily due to the presence of old woodland and the river corridor. Potential impacts of the development in order of conservation significance are:
1. Harm/disturbance to a range of bat species using trees on site for roosting. 2. Habitat loss and increased lighting levels post development, likely to impact on
commuting and foraging bats.
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3. Loss of arable fields providing low quality foraging habitat for bats. 4. Severance of flight lines from the woodland to the wider area. 5. Impacts on retained trees and hedgerows used by commuting, foraging and roosting
bats during the construction phase through root impaction/damage. 6. Severance of bat commuting and foraging routes due to infrastructure development
associated with residential development, particularly road links. 7. Increased cat predation following increase in local population. 8. Conversion of arable land to the south of the site to SUDs and Country Park, with site
enhancement as foraging habitat in the medium term. 9. Loss of low value arable land to be replaced by residential development and
associated gardens presenting potential long term advantages regarding roosting and foraging opportunities for pipistrelle bats.
Key mitigation measures include:
Retention of hedges and hedgerow trees.
Buffer strips to the retained woodlands.
Lighting at the site boundaries during development and operation will be low level and low lux (less than 2lux at the boundary feature) and will be directed away from hedgerows, woodland and feature buffers that provide potential commuting and roosting locations. Within the housing areas lighting should be accurately targeted at required locations and of minimum acceptable intensity.
40 timber bat boxes to be placed within the trees bordering the site to provide roost locations in the medium term/during construction.
20 bat boxes, 10 bat slates and 20 ridge tile access points are to be incorporated into the development.
Enhancement will be provide through the creation of the country park with associated wetlands and tree and shrub planting, and the conversion of arable land to open space and gardens.
If you are assessing this report for a local planning authority and have any difficulties interpreting plans and figures from a scanned version of the report, E3 Ecology Ltd would be happy to email a PDF copy to you. Please contact us on 01434 230982.
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INTRODUCTION
E3 Ecology Ltd was commissioned by Signet Planning LLP to undertake bat surveys of land to the west of Lancaster Park near Morpeth. As bats are small nocturnal species that can roost in inaccessible crevices only 16mm wide, it can be very hard to demonstrate that they are absent from a site, particularly given a limited number of visits during part of the year. As a result, assessment and development approaches are based on an informed risk assessment, and where appropriate a reasonable worst-case scenario, in order to ensure that bats are not recklessly harmed by the proposals.
A.1 Background to development
The site is located west of Morpeth, adjacent to the A1, approximately 0.5km east of Mitford, at an approximate central grid reference of NZ 179 862. Site location is illustrated below in Figure 1.
The site is owned by the Shepherd Offshore. It is proposed to construct residential dwellings, a service area, areas of open space and Country Park (Figure 2). The hedgerows on site and adjacent woodland to the east will be protected by a buffer zone. Landscaped SUDS will also be implemented within the proposals in the form of a country park on the southern boundary.
Figure 1 – Site Location
(Reproduced from the ordnance survey map with the permission of the
controller of Her Majesty’s stationery office. CJ Crown Copyright
reserved. Licence number 100039392.)
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A.2 Personnel
Survey work and reporting was undertaken by:
Tony Martin BSc PhD MLI MCIEEM (Natural England Licence No.20120420)
Jessica Andrews BSc MSC Grad CIEEM
Emma Barnes BSc MSc
Silas Walton MSc BSc
Adam Jones BSc The project was supervised/checked by:
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Tony Martin BSc PhD MLI MCIEEM (Natural England Licence No.CLS 02541) Details of experience and qualifications are available at www.e3ecology.co.uk.
A.3 Objectives of study
The objective of the study was to gain a sufficiently detailed picture of bat populations to allow an assessment of the likely impacts of the proposed development on these species, and where necessary to allow mitigation to be designed which minimises the risk of harm and maintains their conservation status in the local area (for example by ensuring that there is no net reduction in the number of available roost sites).
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RELEVANT LEGISLATION AND PLANNING CONTEXT
A.4 National Planning Policy Framework
The government National Planning Policy Framework (NPPF) states the following:
Plan policies and planning decisions should be based upon up-to-date information about the natural environment (Paragraph 158 and 165).
Plan policies should promote the preservation, restoration and recreation of priority habitats, ecological networks and the recovery of priority species (Paragraph 117).
Local planning authorities should set out a strategic approach in their Plans, planning positively for the creation, protection, enhancement and management of networks of biodiversity and green infrastructure. (Paragraph 114).
When determining planning applications in accordance with the Local Plan and the presumption in favour of sustainable development local planning authorities should aim to conserve and enhance biodiversity by applying a number of principles, including if significant harm resulting from a development cannot be avoided, adequately mitigated, or, as a last resort, compensated for, then planning permission should be refused. (Paragraph 118).
A.5 Protected species legislation
Bats
Within England all bat species are specially protected under the Conservation of Habitats and Species Regulations (2010). As a result there is a requirement to consult with Natural England before undertaking any works that may disturb bats or their roost, and under the Conservation of Habitats and Species Regulations it is illegal to.
Deliberately kill, injure or capture bats.
Deliberately disturb bats; in particular any disturbance which is likely to impair their ability:
(i) to survive, to breed or reproduce, or to rear or nurture their young; or
(ii) in the case of animals of a hibernating or migratory species, to hibernate or migrate; or
(iii) to affect significantly the local distribution or abundance of the species to which they belong.
Deliberately obstruct access to a bat roost.
Damage or destroy a bat roost.
Under the Wildlife and Countryside Act (1981) the above offence of disturbing bats includes low level disturbance and as such under this act it is also an offence to:
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Intentionally or recklessly disturb at bat while it is occupying a roost.
Intentionally or recklessly obstruct access to a roost.
Under the above legal protection, only the offences under the Conservation of Habitats and Species Regulations (2012) are strict liability offences; the remaining offences, under the Wildlife and Countryside Act (1981), are offences only where they are carried out "intentionally or recklessly". Defences that were previously available under the Conservation (Natural Habitats, &c.) Regulations 1994, legislation which is superseded by the Conservation of Habitats and Species Regulations (2010), have now been removed. Specifically the 'dwelling-house' defence and the 'incidental result of a lawful operation' defence no longer apply. However the 'incidental result' defence persists within the Wildlife and Countryside Act disturbing bats or obstructing access to a roost and activities that cause low level disturbance may be able to rely on this defence. Under the Countryside and Rights of Way Act 2000 (CROW Act) the offence in section 9(4) of the 1981 Act of disturbing bats is extended to cover reckless damage or disturbance. The Hedgerow Regulations 1997 provide for the conservation of important hedgerows and their constituent trees. The presence of a protected species such as bats is a relevant consideration when assessing whether a hedgerow is important and may influence a local planning authority’s decision on whether to approve removal of such hedges. As of October 1 2006, public authorities have a duty to conserve biodiversity under the Natural Environment and Rural Communities (NERC) Act 2006.
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SURVEY AREA AND METHODOLOGY
A.6 Survey area
Figure 3 illustrates the site boundary whilst Figure 4 illustrates the broad habitats present on site and within an approximate 500m buffer zone.
Figure 4 – Aerial photograph centred
on the site with a 500m radius
illustrating the setting and the habitats
it supports
(Reproduced under licence from
Google Earth Pro.)
Figure 3 – Aerial photograph illustrating the
extent of the site with a redline boundary
(Reproduced under licence from Google
Earth Pro.)
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The study area includes the site and adjacent land to allow for possible secondary impacts in line with Natural England recommendations.
A.7 Methodology
A.7.1 Desktop study
Initially, the site was assessed from aerial photographs and 1:25000 OS plans. Following this, consultation was undertaken with the Local Records Centre and the MAGIC website was checked for any notable sites or habitat or species records.
A.7.2 Survey equipment
The following items of equipment were utilised during survey work and analysis:
Zeiss 8x30 binoculars
Leica Ultravid 8 x 32 binoculars
Duet bat detector MP3/WAV digital recorder Batsounds software
Anabat recorder with GPS unit Anabat expresses
Analook software
A.7.3 Phase 1 habitats
Phase 1 survey suggested that the site was likely to be of moderate value for bats, being dominated by arable land, but with well treed hedges and woodland at the site boundaries. Autumn survey recorded low levels of bat activity, so survey effort was based on a lower value site with spring, summer and autumn surveys. Initial Inspection A daytime assessment was made of all trees on site that may be affected by the proposed development, in order to evaluate their potential for supporting bat roosts, and where present to record signs of use by bats. Trees were inspected for features that could potentially be used by roosting bats, such as crevices, splits, holes and sections of raised bark, were identified. Any field signs that could indicate bat use, such as droppings, staining and scratch marks, were noted. Transect Surveys The route was assessed on google earth in order to fully assess any health and safety issues, the time transects would take and to determine the best places to include fixed monitoring points. Transects were completed within two hours of sunset and incorporated easily identifiable landscape features to aid navigation and to divide the route into sections of similar habitat type. Routes were chosen that incorporate habitat features with potential for use by foraging and commuting bats as well as potential low value habitats, giving a good sampling of the site and
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its setting as a whole. The routes incorporated fixed monitoring points at important features such as hedgerow “crossroads” along the route, but also sought to sample all habitat types within the survey area, not just higher value features. The fixed monitoring points gave a better assessment of use of habitats by species such as Daubenton’s bat and woodland bat species, that may otherwise have been missed. At each monitoring point, the surveyor recorded the number of bat passes per species for 3 minutes, together with light level and temperature. Weather conditions were recorded at the start and end of the survey, together with any significant changes during the survey, which may have influenced bat activity. Given good calls many species, including common and soprano pipistrelles, and noctule can be identified with a good degree of confidence. The Myotis genus of bats are much harder to separate reliably as their frequency modulated calls are very similar. For these species either slope analysis of Anabat calls or a combination of call loudness, frequency range, habitat and flight characteristics can be used to provide a best estimate. Whiskered, Brandt’s and Alcathoes bats were not separated. In the text bats are identified as accurately as possible, within the constraints identified above. If the species name is given without qualification, the record was of good quality. If there is a degree of uncertainty this is indicated by a question mark, e.g. ?brown long-eared. If identification to species is not practicable then just the Genus or ‘bats’ is used. Anabat monitoring Fixed remote monitoring equipment was utilised for long term monitoring (approximately a week) throughout both the 2013 and 2014 survey season. This method was also employed during transect surveys to allow a robust assessment of bat usage across the site. Analook software was then used to identify calls by species using slope analysis if necessary. The following criteria will be used to assess the value of the site in terms of the data captured.
Very high High Medium Low Very low
Bat passes per hour1 (species / files)
>100 >100 >20 5-20 0-5
Bat numbers from species records, VP and transect surveys
>100 >10 >4 <4 1
Bat species regularly occurring
>5 >4 2-4 1-2 1
Levels of activity recorded will be a function of the number of bats and the particular behaviour
in the vicinity of the monitoring point, with higher levels of activity associated with higher
numbers of passes of individual bats (e.g. a key foraging area use by individual/small
numbers) and/or use of the area by multiple bats (e.g. a key foraging area or commuting route
used by numerous bats).
1 Bat passes are based on Anabat files and the species they contain, if one file contains three species it is scored as three passes. Whilst this technique is flawed, a single file may contain a couple of echolocation pulses or 100, is it simple and pragmatic and is simply intended to provide another tool to help assess likely conservation value.
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The value of the area will be a function of both the levels of activity recorded and the range of
species present. If high levels of activity are combined with a good range of bat species then
conservation value is likely to be of district value or above. Often the site will actually be part
of a wider network of habitats, such as a river corridor, all of which is required to support the
bat population of high conservation value.
Bat activity varies greatly through the night and early evening and later dawn activity is likely
to be focussed in the vicinity of roosts. High levels of activity through the body of the night are
likely to be associated with either favoured foraging locations for individual bats or particularly
high value habitat.
Direct comparison of activity levels between species is not possible due to the differences in
‘detectability’ with larger species such as noctule detectable over greater distances (up to
around 100m) and species such as brown long eared detectable only over a few metres.
Activity levels determined from bat calls within woodland are likely to underestimate levels of
bat activity due to the quiet high frequency calls that most bats will use in a cluttered
environment. As a result a higher value is given to records of ‘woodland’ bat species
(Natterer’s, brown long-eared, and WAB) which are generally detected over a shorter range.
2 fixed, remote monitoring Anabat detectors were installed at Mitford on 20th September 2013 and recorded bat calls for 7 nights. In 2014 fixed remote monitoring points were installed from the 22nd - 27th April and 14th – 19th of August. Single night monitoring due to equipment concerns were carried out on the 21st May and 18th June. Transect surveys were supplemented using remote monitoring data during surveys on the 21st May and 18th June.
A.7.4 Timing
Initial inspection of the trees onsite was undertaken on the 28th August 2013, as part of the extended phase 1 survey. A total of 3.5 hours was spent on site. Transect surveys were undertaken on the following dates: Activity Surveys
Date Start Time End Time Time of Sunset No. of
Surveyors No. of Remote
Monitoring Points
2013
28.08.13 20:05 22:10 20:08 2 0
16.09.13 19:28 21:10 19:20 4 0
19.09.13 19:17 20:35 19:13 4 0
26.09.13 19:05 20:41 18:57 4 0
2014
22.04.14 20:15 22:00 20:24 1 1
22.05.14 21:15 22:55 21:20 2 0
25.05.14 20:15 22:40 21:24 1 0
18.06.14 21:55 22:20 21:49 4 1
17.07.14 21:30 23:30 21:34 4 0
Poor weather conditions on 16th September 2013 (strong winds and light rain) may have constrained bat activity, but the remaining surveys, combined with Anabat monitoring, are thought to provide an accurate representation of activity on site.
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A.7.5 Weather conditions
Date Start Temp. End Temp. Cloud
Cover
Precipitation Wind
Conditions
Time of
Sunset/rise
2013
28.08.13 18ºC 13ºC 5%-50% 0 1-2w 20:08
16.09.13 10.6ºC 9.9ºC 0 – 10% 0 3-5 19:20
19.09.13 15ºC 12.9ºC 95% 0 1 19:13
26.09.13 19ºC 16.4ºC 90% 0 1 18:57
2014
22.04.14 10 10 100% 0 0 20:24
22.05.14 17 14 95% 0 2 21:20
25.05.14 12 12 80% 0 0 21:24
18.06.14 - - 20% 0 1 21:49
17.07.14 22 16 100% 0 0 21:34
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RESULTS
A.8 Desktop study
A.8.1 Pre-existing information
OS map & aerial photographs Figures 1 (A1) and 4 (C1) show that the general land use in the surrounding area is largely arable farmland and intensively managed grassland. The urban edge of Morpeth lies to the east, while the site is directly adjacent to the A1 on the western boundary. The most recent aerial photograph of the site (Figure 3, C1, 2009) indicates that habitats on site are dominated by arable farmland bounded by hedgerows, with an area of woodland to the eastern boundary. Historical imagery suggests that land use has remained the same since at least 2002. MAGIC website Consultation of the government’s Multi Agency Geographic Information for the Countryside (MAGIC) website indicated that the following local nature reserves lie within a 2km radius of the site:
Borough Woods (530m south)
Bracken Bank (800m east)
Carlisle Park (1.4km east)
Davies Wood (900m east)
Scotch Gill Wood (280m east) The MAGIC website also identified numerous stands of ancient semi-natural woodland in the local area, including that which borders the site to the east. Further ancient, semi-natural woodlands lie approximately 800m to the west and 500m to the south. Previous work Work carried out by AECOM relating to the Morpeth Northern Bypass confirmed common and soprano pipistrelle roosts, and a probable noctule or Leisler’s roost, within trees along the northern boundary of the site in 2012.
A.8.2 Consultation
Consultation with ERIC NE provided records of the following bat species within a 2km radius of the site: Daubenton’s bat, Natterer’s bat, noctule, common pipistrelle, soprano pipistrelle and brown long-eared bat.
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A.8.3 Bat risk assessment
Risk of supporting roosting bats2
Minimal Low Medium High
Habitats and Setting
Habitats and
cover within 200m City Centre
Open, exposed
arable, amenity
grass or pasture
Hedges and
trees linking site
to wider
countryside
Excellent cover
with mature trees
and/or good
hedges
Habitats within
1km City Centre
Little tree cover,
few hedges,
arable dominated
Some semi-
natural habitats,
trees hedges etc
Good network of
woods, wetland
and hedges
Alternative roosts
within 1km
City centre
Numerous
alternative roost
sites of a similar
nature
A number of
similar buildings
in the local area
Few alternative
buildings and site
of good quality for
roosts
Setting Inner city Urban with little
green space
Build
development with
greenspace,
wetland, trees
Rural Lowland
with woodland
and trees.
Distance to
water/marsh
>1km 500m-1000m 200m-500m <200m
Distance to
woodland/scrub
>1km 500m-1000m 200m-500m <200m
Distance to
species-rich
grassland
>1km 500m-1000m 200m-500m <200m
Commuting
routes
Isolated by
development,
major roads,
large scale
agriculture
No potential
flyways linking
site to wider
countryside
Some potential
commuting
routes to and
from site
Site is well
connected to
surrounding area
with multiple
flyways
Overall, the setting is considered to be of moderate to high potential for supporting roosting and foraging bats. The presence of ancient woodland and good quality hedges, watercourses and species rich grassland within the immediate local area provides excellent foraging and roosting resources for a variety of bat species. However, there are multiple alternate roost sites for bats such as pipistrelles, which will use the housing to the east for roost locations, and for woodland bats with abundant late maturity trees in the wider local area.
2 This risk assessment technique has been audited through a research project with York University which
compared the risk assessment scoring with the results of detailed field assessment for over 100 sites. Statistically significant associations were found between habitat setting and building features and the presence of absence of different bat species. For example habitat connections and nearby woodland were significant for brown long-eared bats and the presence of species-rich grassland is important for many species.
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A.9 Field survey
A.9.1 Habitats
Foraging habitats The hedgerows on site and semi-natural ancient woodland to the east of the site will provide good quality foraging habitat for bats, as well as providing linkages to the wider area and river Wansbeck. The arable fields will provide lower quality foraging habitat for bats. Commuting routes The site is well connected to the wider landscape, with linear commuting routes along hedgerows to the surrounding land to the north and south as well as to and from the residential area to the east. The A1 motorway, directly to the west of the site, provides a potential barrier to commuting bats. Field survey indicated that the hedgerow along the northern boundary of the southernmost arable field was used as an east-west commuting route by a range of bat species at dusk. Exposed/sheltered The arable fields are relatively exposed; with hedgerows and woodland to the east providing more sheltered foraging. Potential alternative roost locations There are abundant alternative roost locations nearby, within the residential area to the east of the site and woodland to the east and south.
A.9.2 Trees
Tree species within the hedgerows on site mostly comprise pedunculate and sessile oak, ash, sycamore, beech, hazel, mountain ash, elder and buckthorn. The majority of field trees are of moderate, or low to moderate risk of supporting bat roosts, approaching late maturity but generally only containing a small number of features potentially suitably for roosting bats. A smaller number of trees are of high risk, the locations of which are indicated in Figure 4 below:
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A.9.3 Activity surveys
A.9.4 2013
Dusk transect survey on 28th August started at 20:05 and finished at 22:10. Two surveyors completed transects of the site, one in the northern section and the other the southern section, repeating the transect route twice, once at twilight to seek to record bats close to their roosts and any key commuting routes, and once in the dark (less than 1 lux) to assess bat use once they had dispersed over the wider countryside. The weather started out slightly windier than ideal (2), but became calm.
Light levels were suitable for pipistrelle emergence from around 20.15, but the first bat record was at 20.31 adjacent to the woodland at the south of the site, and at 20.44, close to the existing housing at the north of the site. From 20.45 light levels were suitable for Myotis sp. emergence, and the first record was at 20.53 to the north of the site, suggesting a possible tree roost within the site. In the southern area the first Myotis sp. record was at 21.13
The second transects started around 8.55 when light levels were below 0.6 lux. Analysis of the data suggests that most bats are roosting off-site and coming into the area to forage once it is dark. There is some evidence of higher levels of pipistrelle bat activity within the existing
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housing area than within the arable land of the site. Figures 5 and 6 below show transect route and the bat activity recorded during each of the “dusk” and “dark” periods.
Dusk transect survey on 16th September started at 19:25 and finished at 21:10, covering four transect routes over the site, again once at dusk and once when fully dark. Weather conditions were not ideal, with wind of 3 – 5 Beaufort scale, which is likely to have limited bat activity. Very low levels of common and soprano pipistrelle activity only were recorded, mainly associated with the housing and woodland edge to the east of the site.
Figures 5 & 6 – Dusk and dark bat activity transect data 28.08.13
Red: Common pipistrelle, Green: Soprano pipistrelle, Blue: Myotis
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Dusk transect survey on 19th September indicated low common and soprano pipistrelle activity throughout the site at dusk, particularly focussed at hedgerow boundaries and towards the west of the site. Three whiskered/Brandt’s bat passes were also recorded, again towards the western edge of the site. During the second, “dark” transect, similar levels of activity were seen, with more bat passes being focussed towards the ancient woodland to the east of the site. Again, several whiskered/Brandt’s passes were recorded, as well as noctule activity.
Figures 7 & 8 – Dusk and dark bat activity transect data 16.09.13
Red: Common pipistrelle, Green: Soprano pipistrelle
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On 26th September similar levels of activity were again seen, with the majority being common and soprano passes associated with the field boundaries. Low levels of noctule and whiskered/Brandt’s activity were again recorded. During the second transect, common pipistrelle activity was also recorded within an open arable field towards the south of the site, indicating that this is of some value to bats. Lower levels of soprano pipistrelle were recorded, again with low numbers of whiskered/Brandt’s passes recorded.
Figures 9 & 10 – Dusk and dark bat activity transect data 19.09.13
Red: Common pipistrelle, Green: Soprano pipistrelle, Blue: Myotis, Yellow: Noctule
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Anabat Monitoring 20.09.13 – 27.09.13 Two anabat monitors were used to record bat activity remotely on site for a week long period. The location of these detectors is illustrated in Figure 13 below:
Figures 11 & 12 – Dusk and dark bat activity transect data 26.09.13
Red: Common pipistrelle, Green: Soprano pipistrelle, Blue: Myotis.
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Both Anabat detectors recorded common and soprano pipistrelle and Myotis sp. activity (likely to be Whiskered/Brandt’s). The northern detector recorded a total of 493 bat passes over the course of the week, with 69% of this activity being common pipistrelle bats. Another 21% of activity was soprano pipistrelle bats, with 10% of activity being Myotis sp. bats. Earliest pipistrelle activity was recorded at 19:09 and 19:11 for common and soprano bats respectively, which is within ten minutes of sunset, suggesting roost locations close by, probably within the housing to the east. Earliest Myotis sp. activity was recorded at 19:41, again indicating possible roosts within the local area – potentially within the good quality woodland to the east. The southern Anabat detector recorded a total of 748 bat passes. Again the majority of activity was by common pipistrelle bats, with 63% of records being attributed to this species. 36% of activity was soprano pipistrelle passes, with just 1% being Myotis sp. bats. First common pipistrelle activity was recorded slightly later at 19:20 at this location, possibly due to bats from roosts to the north dispersing down to this area. Soprano pipistrelle activity, however, was recorded earlier, at 19:02, indicating a possible tree roost within this area. Myotis sp. activity was not recorded until 21:22, which is likely to be foraging activity during the “dark” period.
Northern
anabat
Southern
anabat
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A.9.5 2014
A.9.5.1 Transect Surveys
A dusk transect by one surveyor across the whole site on the 22nd April recorded low levels of pipistrelle (common and soprano) activity. All recordings occurred at the southern end of the site with the first recording of a pipistrelle at 20.55, at an approximate lux of 2.0, half an hour after expected pipistrelle emergence times. Figure 14 and 15 display the survey results map and evening lux levels respectively.
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0
20
40
60
80
100
120
140
20:20 20:25 20:35 20:45 20:54 21:10
Lux
Time
Lux 22.04.14
Dusk Transect on the 22nd May 2014 was conducted by two surveyors and thoroughly covered the northern extent of the site. Low to moderate levels of activity were recorded which was focused along boundary features such as the hedgerows and woodland edge habitats on site. A wider range of species was recorded when compared to other surveys with common and soprano pipistrelle, noctule and Daubenton’s. Due to dense cloud cover and measurements within the shade of marginal habitats lux levels at the start of the survey were approximately 30. The first bat record was at 21:48 (common pipistrelle) at a lux of 3.6. The first Myotis sp. record was at 22:33 at an approximate lux level of 0.4, 25 minutes after expected Myotis sp. emergence lux levels. Figure 16 below displays the survey data map.
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Survey of the site was conducted by one surveyor on the 25th May and recorded low level use of the site by common and soprano pipistrelle and noctule bats. First pipistrelle activity was recorded at 21:56, 30 minutes after sunset, with noctule recorded earlier (first recording at 21.20) commuting across the site. Figure 17 below displays the transect data map.
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Survey on the 18th June was conducted by 4 surveyors and recorded low to moderate levels of bats activity across the site, again focussed along hedgerows and tree lines. The first pipistrelle records across all transects occurred at approximately 22:20, at a lux of around 30, 15 minutes after expected emergence lux for this species. The first, and only, Myotis sp. record occurred at 22:40 at an approximate lux of 4.8 which due to the early timing with regards to typical Myotis sp. emergence lux levels is suggested to be roosting within the site or immediately adjacent to it. Figure 18 and 19 below display transect data and lux levels.
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0
50
100
150
200
250
300
21:50 22:11 22:16 22:28 22:35 22:45 22:58
Lux
Time
Lux 18.06.14
Survey on the 17th July 2014 recorded low levels of bat activity across 4 transects. The first pipistrelle activity occurred at 21:55 next to the houses at the north eastern extent of the site, at an approximate lux of 50, which would suggest a roost within or very close to the site, suggested to be within the adjacent houses. Individual noctule and whiskered/Brandt’s or Alcathoe’s calls were recorded to the south of the site within close proximity of the River Wansbeck, see Figures 20 and 21.
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Survey on the 18th of September recorded similar levels of activity as previous transect surveys with a focus of activity associated with the woodland to the south of the site. First records occurred after sunset (19:16) with common pipistrelle and soprano pipistrelle occurring at 19:37 and 19:27 respectively and noctule at 19:33. Due to overcast and misty weather conditions lux levels at the start of the survey were already low and as such lux levels are not utilised within analysis. A vantage point survey was conducted (location marked on transect map below) to assess the usage of a hedgerow as a commuting route which was highlighted following analysis of static monitoring data. The data is displayed in the table below and all sightings of bats recorded a net movement from the housing to the east of the site, supporting suggestions of a roost within these buildings. Figure 22 and 23 display the VP results and transect map respectively.
Species First Record Number
Common Pipistrelle 19:37 9
Soprano Pipistrelle 19:34 7
Noctule 19:33 3
Pipistrelle 19:36 3
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A.9.5.2 Static Monitoring
Figure 24 below displays static monitoring locations utilised during 2014;
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Spring monitoring recorded low levels of activity with a maximum species count and passes/hr of 4 and 8 respectively. First record times occurred approximately 20 – 30 minutes after sunset. Summer monitoring recorded increased levels of activity with a maximum species count and passes/hr of 5 and 16.7 respectively. First record times occurred after sunset, with the earliest being around 20 – 30 minutes prior. Autumn monitoring recorded a further increase to a moderate level of activity and a high number of bat species. A maximum species count and passes/hr of 7 and 43.6 were recorded respectively. Pipistrelle activity generally, across all locations, occurred early, around sunset times and it is therefore suggested autumn roost locations are present within or immediately adjacent to the site, with woodland edge exhibiting a focus of activity. Myotis sp. activity also occurred in the early evening with the majority of activity between 21:00 and 23:00 with very limited dawn activity from this genus. The woodland edge (8) during the August monitoring exhibited a higher proportion of pipistrelle activity, with the majority exhibiting social calls. The bulk of activity occurred early evening around sunset which would indicate a roost either within the surrounding trees or adjacent houses. Data from location 2 recorded high levels of pipistrelle activity and as such a VP survey was conducted to assess the importance of this feature as a potential commuting route. Data exhibited a net movement of bats from the housing to the east, supporting suggestions of a roost within this area.
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The range of species and time of year (mating season) resulted in a wide variety of calls. Call ID was carried out using slope analysis however some calls were either hidden by lower frequency calls recorded at the same time or were too short to be accurately identified. In this instance the call is labelled as ‘bat’. Myotis is used in the same instance however when the call is clearly a Myotis species.
A.9.5.3 2014 Overview:
Transects Overview: Activity across the site is moderate to low. The boundary features such as hedgerows and woodland support the majority of activity recorded. Amalgamation of raw data would suggest activity is also focused around the eastern side of the site. Static Monitoring Overview:
Very high High Medium Low Very low
Bat passes per hour3 (species / files)
>100 >100 >20 5-20 0-5
Bat numbers from species records, VP and transect surveys
>100 >10 >4 <4 1
Bat species >5 >4 2-4 1-2 1
Utilising the above table the value of the site was assessed across the 3 seasons, using an average of all data captured within the period defined (full data displayed within the appendix). Maximum species count was 7 and maximum bat passes per hour within a night was 43.6 (August) with minimum species count being 1 with 0.2 passes per hour (April).
April (Spring) May/June (Summer) August (Autumn)
Passes per hour 3.4 9.3 19.9
Species 2.5 3.8 4.7
Numbers Medium High High
Value Low Medium High
Although bat passes per hour are generally in the low to medium range, the number of species present and bat number categories increase the value of the site. The 2014 increase throughout the year could suggest the site is important during the autumn period after maternity roosts have dispersed.
3 Bat passes are based on Anabat files and the species they contain, if one file contains three species it is scored as three passes. Whilst this technique is flawed, a single file may contain a couple of echolocation pulses or 100, is it simple and pragmatic and is simply intended to provide another tool to help assess likely conservation value.
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ASSESSMENT
The value and significance of the habitats and species found was assessed against the following criteria developed from the Guidelines for Ecological Impact Assessment produced by the Institute of Ecology and Environmental Management4.
Level of Value
Examples
International
An internationally designated site or candidate site.
A viable area of a habitat type listed in Annex I of the Habitats Directive, or smaller areas
of such habitat, which are essential to maintain the viability of a larger whole.
Any regularly occurring population of an internationally important species, which is
threatened or rare in the UK.
Any regularly occurring, nationally significant population/number of any internationally
important species.
National
A nationally designated site.
A viable area of a priority habitat identified in the UK BAP, or smaller areas of such
habitat, which are essential to maintain the viability of a larger whole.
Any regularly occurring population of a nationally important species, which is threatened
or rare in the region or county.
A regularly occurring regionally or county significant population/number of any nationally
important species.
A feature identified as of critical importance in the UK BAP.
Regional
Viable areas of key habitat identified in the Regional BAP or smaller areas of such
habitat, which are essential to maintain the viability of a larger whole.
A regularly occurring, locally significant number of a regionally important species.
Bats: large maternity sites used by rare species in the region, including Nathusius
pipistrelle, Leislers and Brandts bats.
County
County designated sites.
A viable area of a habitat type identified in the County BAP.
Any regularly occurring, locally significant population of a species which is listed in a
County “red data book” or BAP on account of its regional rarity or localisation.
A regularly occurring, locally significant number of a species important in a County
context.
Bats: large maternity sites used by uncommon species in the region, including
Daubenton, Natterers, soprano pipistrelle, noctule, brown long eared and whiskered bats;
or small to moderate maternity roosts, hibernation and autumn swarming roosts used by
rare species
District
Areas of habitat identified in a District level BAP.
Sites designated at a District level.
Sites/features that are scarce within the District or which appreciably enrich the District
habitat resource.
A population of a species that is listed in a District BAP because of its rarity in the locality.
Bats: small numbers of non-breeding rare species (5+); small-moderate maternity or
hibernation roosts used by uncommon species, large maternity roost of common species
to the region (common pipistrelle)
Parish
Area of habitat considered to appreciably enrich the habitat resource within the context of
the Parish.
Local Nature Reserves.
Bats: large hibernation, small-moderate maternity and autumn swarming roosts of species
common; small numbers of uncommon species or occasional (1-4) roost of rare species
4 Institute for Ecology and Environmental Management (2006) Guidelines for Ecological Impact Assessment in the
United Kingdom (Version 7 July 2006). http:/www.ieem.org.uk/ecia/index.html.
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Level of Value
Examples
Local
Habitats and species that contribute to local biodiversity, could only be replicated in the
medium term, but are common in the local area.
Loss of such habitats would ideally be mitigated if local biodiversity is to be conserved
and enhanced.
Bats: small numbers of common species, feeding/individual roosts of uncommon species
or feeding roosts of rare species.
Low
Habitats of poor to moderate diversity such as established conifer plantations, species
poor hedgerows and unintensively managed grassland that may support a range of Local
BAP species but which are unexceptional, common to the local area and whose loss can
generally be readily mitigated.
Utilising the table above it is suggested that the site is of local value to bats due to the assemblage of habitats on site and suggested roosts in the local area. In part this rather low evaluation is a reflection of the high quality habitats present in this and neighbouring parishes, such that the main body of the site (the woodland lies out with it) is unexceptional.
A.10 Assessment of survey findings
Transect surveys indicate that the arable fields on site provide low quality foraging habitat to bats, which is used only occasionally. The majority of activity is related to the woodland boundaries to the south and east and with the hedgerow field boundaries, which are used consistently by common and soprano pipistrelle bats and low numbers of whiskered/Brandt’s bats. Occasional noctule have also been recorded on site. It is considered likely that the housing to the east of the site supports pipistrelle roosts, with early activity recorded in the northern section of the site. It is possible that the site also supports tree roosts to the south, possibly of soprano pipistrelle and whiskered/Brandt’s bats given timings of activity. The 2014 surveys highlighted a peak in activity during the autumn period, with a shift in site usage throughout the year. Spring depicted a low value site for bats, summer a medium value site and in autumn a high value site. Due to timings of first records it is considered that this indicates the presence of soprano and common pipistrelle and potential Myotis sp. maternity roosts within either the trees or houses immediately adjacent to the site. The increased numbers and activity in the autumn is likely to reflect the dispersal of off-site maternity roosts, particularly for pipistrelle bats, which are likely to use houses, and establishment of individual roosts and perhaps mating roosts in the woodland and trees.
A.11 Impacts
Bats are most vulnerable to disturbance during June, July and August, when they are breeding, and between November and March when they are hibernating. Potential Impacts of the proposed development are considered to be:
Harm/disturbance to a range of bat species using trees on site for roosting.
Habitat loss and increased lighting levels post development, likely to impact on commuting and foraging bats.
Loss of arable fields providing low quality foraging habitat for bats.
Severance of flight lines from the woodland to surrounding wider area.
Potential Impacts on retained trees and hedgerows used by commuting, foraging and roosting bats during the construction phase through root impaction/damage.
Severance of bat commuting and foraging routes due to infrastructure development associated with residential development, particularly road links and associated lighting.
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Increased cat predation following increase in local population.
Conversion of arable land to the south of the site to SUDs and Country Park, with habitat enhancement in the medium term.
Loss of low value arable land to be replaced by residential development and associated gardens presenting potential long term advantages regarding roosting and foraging opportunities for pipistrelle bats.
A.12 Constraints
Poor weather during the survey of 16.09.13 is likely have constrained bat activity, however all other surveys are considered to provide an accurate assessment of site use.
MITIGATION AND RECOMMENDATIONS
A.13 Further survey
If development does not happen within 12 months of this report, an updating survey will be required, ideally between May and September. It is recommended that aerial bat surveys are carried out of trees assessed as being of high risk of supporting roosting bats if they are to be lost due to the development.
A.14 Mitigation requirements
Site master planning has sought to retain trees and hedgerows and create a buffer to the areas of woodland.
Lighting at the site boundaries during and post development will be low level and low lux (less than 2lux at the boundary feature) and will be directed away from hedgerows and woodland that provide potential commuting and roosting locations.
40 timber bat boxes to be placed within the trees bordering the site to provide roost locations in the medium term/during construction.
Habitat Creation and Enhancement Habitat creation in the country park will include open water, reed beds, grassland, scrub and new woodland planting, greatly enhancing bat habitats over the arable field currently present. New areas of public open space and gardens will enhance habitats for pipistrelle bats compared with the arable land currently present. 20 bat boxes will be incorporated within the proposed new build, preferentially within garages close to the woodland, to provide alternative roost sites5. Boxes will be erected as high as possible, ideally at a minimum height of 4m. Boxes will include 10 suitable for use by breeding, and 10 suitable for hibernation use by small numbers of bats. Crevice Roost Sites
5 The number of bat boxes proposed is based on research that has indicated that typically 10% of boxes will be
used by bats, so if 5 roosts are to be created one needs to provide 50 boxes.
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A total of 10 purpose designed “bat slates” will be incorporated into roofs of the new development to provide access to the gap between the roof tiles and the roof lining (see Appendix 7). Access to the underside of the ridge tiles will be provided in 20 locations through 20mm diameter gaps in the pointing. Access between ridge tiles will be provided through gaps in the mortar joints. Good working practices The following measures should be included as general good working practice:
Timber treatments that are toxic to mammals will be avoided. If required, timber treatment will be carried out in the spring or autumn. Both pre-treated timbers and timber treatments will use chemicals classed as safe for use where bats may be present (see http://www.jncc.gov.uk/pdf/batwork_manualpt4.pdf).
External lighting that may reduce bat use of the buildings will be avoided. High intensity security lights will be avoided as far as practical, and any lighting in areas identified as being important for bats will be low level (2m) and low lux (<2). No lighting will be installed along the flyways between the roosts and adjacent trees, woodland and foraging areas. Where security lights are required, these will be set on a short timer and will be motion sensitive only to larger objects. Road lighting within the housing areas will be at the minimum level to meet design standards, and LED to reduce spillage.
The landscape planting will be designed to enhance structural diversity, and will include plants bearing flowers, nectar and fruits which are attractive to invertebrates, thereby helping to maintain the food resource for bats and wildlife generally.
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APPENDICES
A.15 Appendix 1: Stationary Data
Date Location First
Record Last
Record Sunset Sunrise Species Passes Passes/hour Species
21.05.14 3 21.48 23.33 21:18 04:49 Noc 5 0.67
22.03 3.53
45 14 1.86
Total
Passes 19 2.53 2
21.05.14 1 22.01 4.04 21:18 04:49 45 45 5.99
22.21 1.49
55 9 1.20
2.51
Myo 1 0.13
23.26 2.09
pip 17 2.26
23.52 1.5
WAB 2 0.27
Total
Passes 74 9.84 5
21.05.14 4 21.15 2.07 21:18 04:49 55 4 0.53
21.02 2.58
45 43 5.72
21.48
Myo 1 0.13
21.31
Noc 1 0.13
23.1
WAB 1 0.13
Total
Passes 50 6.65 5
21.05.14 5 21.59 4.1 21:18 04:49 55 78 10.38
22.09 3.06
45 45 5.99
22.38 3.52
Noc 2 0.27
Total
Passes 125 16.63 3
18.06.14 6 22.1 23.39 21:49 04:27 45 41 6.18
22.32 23.37
55 13 1.96
22.07 22.59
Noc 8 1.21
22.32 23.12
WAB 10 1.51
Total
Passes 72 10.85 4
22.04.14 2 20.57 21.24 20:24 05:47 45 4 0.43
Total
Passes 4 0.43 1
23.04.14
20.54 23.21 20:26 05:45 45 41 4.40
21.02 23.05
55 27 2.90
21.13 21.39
Noc 4 0.43
Total
Passes 72 7.73 3
24.04.14
20.55 0.45 20:28 05:43 45 2 0.22
0.09 1
55 2 0.22
Total
Passes 4 0.43 2
25.04.14
0.53
20:30 05:40 45 1 0.11
2.18
Noc 1 0.11
Total
Passes 2 0.22 2
26.04.14
20.59 23.53 20:32 05:38 45 47 5.16
21.05 23.33
55 25 2.75
23.18
WAB 1 0.11
Total
Passes 73 8.02 3
27.04.14
21.09 4.43 20:34 05:36 45 24 2.66
0.2 3.02
55 4 0.44
0.53 3.36
Pip 8 0.89
21.34
WAB 1 0.11
Total
Passes 37 4.10 4
14.08.14 2 21:11 23:33 20:42 05:39 WAB 13 1.45
22:12
Nyctalus 1 0.11
20:55 23:43
Noc 5 0.56
22:23 23:06
Nat 2 0.22
21:38 23:34
Myotis 5 0.56
20:56
Daub 1 0.11
21:05 21:55
BLE 4 0.45
22:22
Bat 1 0.11
20:46 23:25
55 58 6.48
20:40 23:36
45 111 12.40
Total
Passes 201 22.46 7
15.08.14
20:25 23:25 20:40 05:41 45 47 5.21
20:30 23:20
55 38 4.21
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20:36
BLE 1 0.11
20:54 23:15
Myo 4 0.44
20:46
Nat 1 0.11
20:57 22:26
Noc 3 0.33
21:23 23:16
WAB 15 1.66
Total
Passes 109 12.09 6
16.08.14
21:22 03:59 20:37 05:43 45 38 4.18
22:40 03:46
55 10 1.10
22:59 03:03
Myo 8 0.88
22:22 02:26
Noc 2 0.22
21:52 03:21
WAB 7 0.77
Total
Passes 65 7.14 4
17.08.14
21:04 03:18 20:35 05:45 45 145 15.82
21:18 03:24
55 100 10.91
21:47 22:28
BLE 2 0.22
21:35 02:44
Myo 6 0.65
22:09
Noc 1 0.11
21:47 23:44
Pip 5 0.55
21:35 02:38
WAB 20 2.18
Total
Passes 279 30.44 5
18.08.14
20:25 00:34 20:33 05:47 Pip 7 0.76
20:13 00:40
45 113 12.24
20:43 00:33
55 47 5.09
21:08 23:24
BLE 3 0.32
21:02 22:36
Daub 3 0.32
21:29 21:57
Myo 3 0.32
20:58 23:53
Nat 2 0.22
21:20 21:29
Noc 3 0.32
21:07 00:26
WAB 24 2.60
Total
Passes 205 22.20 7
19.08.14
20:10 23:12 20:31 05:48 45 59 6.36
20:09 23:14
55 31 3.34
20:39 22:07
BLE 5 0.54
20:53 22:37
Daub 3 0.32
21:22
Myo 1 0.11
22:01
Nat 1 0.11
20:34 21:48
Noc 2 0.22
20:14 23:07
Pip 2 0.22
20:55 22:46
WAB 5 0.54
Total
Passes 109 11.74 7
14.08.14 7 20:31 23:54 20:42 05:39 45 65 7.26
20:28 21:41
55 41 4.58
21:41
Bat 1 0.11
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20:56 21:17
Daub 3 0.34
20:38 21:37
Myo 2 0.22
20:35 00:00
Noc 3 0.34
20:32 23:42
Pip 3 0.34
20:48 23:57
WAB 32 3.58
Total
Passes 150 16.76 5
15.08.14
20:38 01:13 20:40 05:41 45 34 3.77
20:41 01:16
55 72 7.99
00:15 00:37
Bat 3 0.33
21:08
Daub 1 0.11
22:27
Myo 1 0.11
21:57
Nat 1 0.11
21:38 23:00
Noc 2 0.22
21:04 01:08
WAB 19 2.11
Total
Passes 133 14.75 6
16.08.14
22:43 03:45 20:37 05:43 45 34 3.74
21:15 04:10
55 41 4.51
03:20
Myo 1 0.11
00:07
Noc 1 0.11
21:20 03:04
WAB 11 1.21
Total
Passes 88 9.67 4
17.08.14
21:15 04:03 20:35 05:45 45 253 27.60
21:11 04:11
55 125 13.64
03:22 03:56
Bat 2 0.22
21:33 03:06
Myo 5 0.55
23:36
Noc 1 0.11
00:37 04:00
Pip 2 0.22
22:29 03:41
WAB 12 1.31
Total
Passes 400 43.64 5
18.08.14
20:43 01:18 20:33 05:47 45 177 19.17
20:37 01:17
55 55 5.96
21:10 01:02
Bat 3 0.32
00:33
BLE 1 0.11
22:52
Myo 1 0.11
21:28 00:37
Noc 3 0.32
20:41 22:16
Pip 11 1.19
21:13 01:05
WAB 13 1.41
Total
Passes 264 28.59 5
19.08.14
20:24 23:15 20:31 05:48 45 62 6.68
20:27 23:15
55 34 3.66
22:22 22:44
Bat 3 0.32
21:18
Myo 1 0.11
20:55 22:42
Noc 3 0.32
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20:57 22:55
WAB 5 0.54
Total
Passes 108 11.63 5
14.08.14 8 20:16 23:37 20:42 05:39 45 110 12.29
20:18 23:34
55 63 7.04
22:13 23:16
Bat 6 0.67
20:49 23:33
Myo 2 0.22
20:51
Noc 1 0.11
21:41 23:21
Pip 7 0.78
21:02 23:21
WAB 7 0.78
Total
Passes 196 21.90 4
15.08.14
20:24 22:33 20:40 05:41 45 89 9.87
20:26 22:32
55 25 2.77
21:45
Bat 1 0.11
21:30 22:20
Myo 4 0.44
22:33
Pip 1 0.11
20:50 22:07
WAB 11 1.22
Total
Passes 131 14.53 4
16.08.14
21:04 01:49 20:37 05:43 45 25 2.75
21:21 01:53
55 26 2.86
00:36 01:27
Bat 2 0.22
22:35 01:19
Myo 4 0.44
23:11 01:12
Pip 4 0.44
22:04 01:36
WAB 9 0.99
Total
Passes 70 7.69 4
17.08.14
20:54 22:09 20:35 05:45 45 218 23.78
21:05 21:56
55 16 1.75
21:38
Bat 1 0.11
21:34 21:59
Myo 4 0.44
21:08
Pip 1 0.11
Total
Passes 240 26.18 3
18.08.14
20:09 23:18 20:33 05:47 45 225 24.37
20:18 23:20
55 67 7.26
21:02 21:45
Bat 3 0.32
20:30
Myo 1 0.11
20:28 23:00
Noc 4 0.43
20:20 22:37
Pip 13 1.41
20:39 22:08
WAB 5 0.54 4
Total
Passes 318 34.44
19.08.14
20:35 23:09 20:31 05:48 45 171 18.42
20:45 23:12
55 40 4.31
22:12
Bat 1 0.11
21:44 22:11
Pip 4 0.43
21:09 22:42
WAB 7 0.75
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Total
Passes 223 24.02 3
A.16 Appendix 2: BAT ECOLOGY
Habitat and roost preferences In their guidelines for bat surveys in the Northumbria Region, Natural England indicates the types of building and trees that are more or less likely to support bat roosts:
Presence of built structures which appear to have a high probability of use by bats:-
o Properties older than 1939, with multiple roofs within 200m of woodland or water.
o Properties older than 1914 within 200m of woodland or water.
o Listed buildings or monuments.
o Traditional ranges of farm buildings.
The risk of bat roosts being present will be higher where structures have:
o Pre-20th Century construction.
o A lowland rural setting.
o Woodland, mature trees, species-rich grassland and/or water nearby.
o Large dimension roof timbers with cracks, joints and holes.
o Numerous crevices in stonework and structures.
o Uneven roof covering with gaps, though not too draughty.
o Hanging tiles or roof cladding, especially on south-facing walls.
o Roof warmed by the sun.
o Disused or little used; largely undisturbed.
The risk of bat roosts being present will be lower where structures have:
o Urban setting with little greenspace.
o Heavy disturbance.
o Small, cluttered roof void (particularly for brown long-eared).
o Modern construction with few gaps or crevices that bats can fly or crawl through (though
pipistrelles may still be present).
o Prefabricated of steel or sheet materials
o Active industrial premises
Habitats that increase the risk of bats being present include:
o Presence of trees with a high probability of bat use, including ancient woodland or parkland,
large trees with complex growth form, and trees with cavities, visible damage and loose bark
(Coniferous plantation and young trees are less likely to support roosts). It can be extremely
difficult to be certain of the presence or absence of bat roosts in trees meeting the above
criteria.
o Recent or historical records of bats on the site, or bat roosts in the general area.
o Presence of underground structures such as abandoned mines, tunnels, kilns, cellars or
fortifications which provide appropriate hibernation conditions.
o Where a development has a significant habitat impact on woods, hedgerows with field trees,
parkland, diverse grassland and wetland habitats potential impacts on tree roosts, foraging
habitats and flight-lines should be considered. Species information and population estimates Pipistrelle maternity colonies generally consist of 25 to 100 individuals, but colonies numbering up to 1000 are not uncommon6. Adult females often form large maternity roosts, occupied between May and August, and frequently number around 300 individuals. Males are
6 Roberts, G.M. & Hutson, A.M. 2000. Pipistrelle. British Bats No. 6. The Bat Conservation Trust, London
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often solitary or in small groups during the summer, later congregating with the females at winter hibernation roosts7. Maternity colonies of brown long-eared bats are generally small, consisting of 10 to 20 adults8,9 (although numbers are likely to be underestimated, due to present in inaccessible areas of the roost). The largest colony recorded was located in northwest England and contained 150 individuals10. Natterer’s bats roost within crevices and cavities, typically within hollow trees, old buildings, caves and tunnels11. Maternity colonies comprising up to 200 adult females can be found in buildings during the summer months while bachelor roosts comprising up to 28 males have been recorded during the summer months in Scotland12. Maternity roosts are not exclusively female, with both adult and immature males comprising up to 25% of the colony. Male only colonies have been found with up to 30 bats13. Foraging individuals will perch during the night at roosts near to foraging areas, not used as day roosts. Mostly these roosts are trees or shrubs but barns will also be used14. Whiskered bats, the smallest of the Myotis species, roost in trees and buildings. Nursery roosts can number over 100 bats, and are almost exclusively female bats. This species hibernates singly in caves, hanging on the open wall or in crevices13. Brandt’s bat is thought to have similar roosting behaviour and foraging ecology to the whiskered bat, however, further research is needed to clarify this13. Maternity roosts are critical to the long-term survival of a colony, and disturbance can lead to the young being abandoned to die. Bats that are disturbed and escape in the winter use up a lot of energy, which they cannot replace, as there are few insects about as food.
7 Corbet, G.B & Southern, H.N., 1964. The handbook of British Mammals). 8 Speakman, J. R. et al., 1991. Minimum summer populations and densities of bats in NE Scotland, near the northern borders of their distributions. J. Appl. Ecol.,225: 327-345 9 Entwistle, A.C., 1994. Roost ecology of the brown long-eared bat Plecotus auritus in north-east Scotland. Unpublished PhD thesis, University of Aberdeen, UK 10 Billington, G., 1993. Bat Groups. No. 7. Bat Conservation Trust, London). 11 Stebbings, R.E. 1991. Natterer’s bat Myotis nattereri. In The handbook of British Mammals. 3rd Edition Corbet, G.B. & Harris, S. (Eds) Oxford: Blackwell Scientific. 12 Swift, S. M. 1997 Roosting and foraging behaviour of Natterer’s bats (Myotis Nattereri) close to the northern border of their distribution. J. Zool. (Lond) 242: 375-384. 13 Altringham, J.D. 2003. British Bats. The New Naturalist. Pub. Harper Collins. 14 Smith, P.G. & Racey, P.A. 2005. The itinerant Natterer: physical and thermal characteristics of summer roosts of Myotis nattereri (Mammalia: Chiroptera) J. Zool. Lond. 266: 171-180.