Transect & Static Activity Surveys For Bat Species€¦ · Slate Meadow – Bat Surveys December 2016 The Ecology Partnership Ltd 3 1.0 Introduction Background 1.1 The Ecology Partnership

Transect & Static Activity Surveys

For Bat Species Slate Meadow

Buckinghamshire

Slate Meadow – Bat Surveys December 2016

The Ecology Partnership Ltd 2

Contents

1.0 INTRODUCTION .............................................................................................................................. 3BACKGROUND .............................................................................................................................................. 3SITE CONTEXT AND STATUS ......................................................................................................................... 3DESCRIPTION OF THE PROPOSED DEVELOPMENT ......................................................................................... 4

2.0 METHODOLOGY .............................................................................................................................. 4LIMITATIONS ................................................................................................................................................ 5

3.0 RESULTS ............................................................................................................................................. 5ANABAT EXPRESS DATA .............................................................................................................................. 5TRANSECT ACTIVITY SURVEYS .................................................................................................................. 10

4.0 DISCUSSION ................................................................................................................................... 11ECOLOGICAL VALUE OF THE SITE .............................................................................................................. 11ECOLOGICAL ENHANCEMENTS & RECOMMENDATIONS ............................................................................. 12

Lighting ................................................................................................................................................. 145.0 CONCLUSIONS ............................................................................................................................... 15

6.0 REFERENCES .................................................................................................................................... 16

APPENDIX 1: TRANSECT ACTIVITY SURVEY RESULTS ............................................................. 17



1.0 Introduction

Background

1.1 The Ecology Partnership Ltd was commissioned to undertake transect activity surveys

for bat activity around land at Slate Meadow, Buckinghamshire. In addition, Anabat

Express static recorders were placed in two locations within the site to supplement the

data collected during the transect surveys.

1.2 This report presents the findings of the surveys. Potential mitigation measures and

recommendations for the site will be included within this report.

1.3 Section 2 of this report sets out the methodology of the surveys. In Section 3 the results

of the surveys are presented. The discussion and mitigation recommendations are found

in Section 4. Finally, conclusions are provided in Section 5.

Site Context and Status

1.4 The site is situated between Bourne End and Wooburn Green in Buckinghamshire,

immediately to the north of the River Wye and is set within a semi-rural landscape.

Residential properties and gardens are located to the south, east and west the site with a

tree and shrub lined footpath and arable fields to the north of the site. The OS grid

reference for the site is SU 903 875.

1.5 The boundary of the site is indicated in Figure 1. This is also the approximate survey

boundary.



Figure 1: Approximate red line boundary of the site.

Description of the Proposed Development

1.6 Proposals for the site include a new residential development with associated access roads

and landscaping. The final layout will be informed by a number of surveys of which

ecology is one.

2.0 Methodology

2.1 The surveys followed BCT guidelines (2016). During the manned transect activity

surveys surveyors walked set transect lines to record activity hotspots such as

commuting routes and foraging areas around the site.

2.2 During the transect surveys surveyors were on site 30 minutes before sunset and

observations were maintained until a minimum 2 hours after sunset. Bat species usually

emerge about twenty minutes after sunset depending on the species, light level, weather

conditions and time of year. Peak activity will normally last for approximately two hours

after sunset, during times of peak insect activity.



2.3 Anabat Express remote recording devices were also deployed within the site in two

locations for atleast 5 consecutive nights during the survey period. Sound files were then

extracted and analysed using Analook software.

Limitations

2.4 It should be noted that whilst every effort has been made to provide a comprehensive

description of the site, no single investigation could ensure the complete characterisation

and prediction of the natural environment.

3.0 Results

Anabat Express Data

3.1 Anabat express remote recording devices were positioned in two locations on site for 5

consecutive nights in April, May, July, August and September 2016. The devices were

positioned within the north western boundary adjacent to the disused railway footpath

and within the central hedgerow and green corridor. The locations of the Anabat Express

installations are shown below in figure 2. The devices were deployed in areas that were

away from dog walking routes to avoid tampering or theft of the devices during the

recording process.

Figure 2. Anabat Express locations (A) and the site boundary



3.2 A total of 493 bat calls were recorded across the five survey periods along the central tree

lined hedgerow, which included 8 species of bat. This including both common

(Pipistrellus pipistrellus) and soprano pipistrelles (Pipistrellus pygmaeus), nathusius

pipistrelle (Pipistrellus nathusii), noctule (Nyctalus noctula), serotine (Eptesicus serotinus),

brown long-eared (Plecotus auritus), Leisler’s bat (Nyctalus leisleri) and a myotis species of

bat considered likely to be natterer’s bat (Myotis nattererii). The breakdown of the number

of passes from each species recorded is shown in figure 3 below.

Figure 3. Breakdown pass numbers from species recorded along the central tree lined hedgerow

3.3 A total of 332 bat calls were recorded across the five survey periods along the north-

western boundary of the site, which included 7 species of bat. This included both

common and soprano pipistrelles, noctule, serotine, myotis species considered likely to

be natterer’s bat and Leisler’s bat. The results of the surveys from both locations are

summarised within table 1 below.

BLE

Leisler's

MyotisSpp

NathPip

Noctule

45Pip

55Pip

Serotine



Figure 4. Breakdown of species recorded along the north western boundary

Table 1. Anabat Static Recording Results

CentralTree-linedHedgerowBatPasses

BatSpecies

Month Dates Pip45 Pip55 Noctule Serotine BLEMyotisSpp Leisler's

NathusiusPip Total

April 26th-30th 0 29 0 0 0 0 0 0 29

May 13th-17th 52 18 6 1 0 3 0 2 82

July 4th-8th 39 35 86 3 8 5 0 0 176

August 16th-20th 55 65 22 3 4 3 0 0 152

September 26th-30th 8 27 9 1 3 2 3 1 54

Total 154 174 123 8 15 13 3 3 493

NorthWesternBoundary

Month Date Pip45 Pip55 Noctule Serotine BLEMyotisSpp Leisler's

NathusiusPip Total

April 26th-30th 2 1 0 0 0 0 0 0 3

May 13th-17th 0 0 0 0 0 0 0 0 0

July 4th-8th 53 25 85 32 0 0 0 0 195

August 16th-20th 21 25 45 6 5 1 4 0 107

September 26th-30th 5 17 4 1 0 0 0 0 27

Total 81 68 134 39 5 1 4 0 332

BLELeisler'sMyotisSppNoctule45Pip55PipSerotine



Figure 5. Noctule bat call recorded along the northern boundary 06/07/16

Figure 6. Serotine bat call recorded along the central tree lined hedgerow on 18/08/16



Figure 7. Common pipistrelle bat call recorded along the central tree lined hedgerow 17/08/16

Figure 8. Nathusius pipistrelle call recorded along the central tree lined hedgerow 27/09/16



Transect Activity Surveys

Table 2. Bat Transect Survey Weather Conditions

Date Sunset Air Temp

oC

Conditions

10/05/16 20.42 15.3 100% cloud cover, dry but with very light

drizzle towards the end of the survey at 22.10

31/05/16 21.11 12.4 100% cloud cover, northerly breeze

04/07/16 21.23 18.3 80% cloud cover, dry with a light breeze

16/08/16 20.23 21.5 <10% cloud cover, warm and light breeze

26/09/16 18.52 16.9 40% cloud, dry with a light breeze

3.4 In total four species of bat were recorded during the transect surveys, common

pipistrelle, soprano pipistrelle, noctule and serotine. Pipistrelle species were the most

recorded species.

3.5 Whilst activity was spread across the site the majority of activity was recorded along the

northern boundary, the central woodland block and hedgerow and along the river along

the southern boundary. Recorded bat activity is shown in appendix 1.

3.6 Activity from pipistrelle species was spread across the site with foraging activity

recorded within the central tree line and hedgerow, along the river and in the northern

corner of the site. The main commuting routes were the northern boundary and the

central tree lined hedgerow. Soprano pipistrelles were also recorded foraging over the

road and entrance the school adjacent to the eastern boundary.

3.7 Activity from a serotine bat was recorded along the river along the southern boundary.

Only one commuting pass was recorded during the July transect survey.

3.8 Noctule activity was recorded high in the sky over the central tree lined hedgerow and

included commuting and foraging activity. Noctule bats were also recorded commuting



over the northern corner of the site along the disused railway line in the July summer

survey.

4.0 Discussion

Ecological Value of the Site

4.1 The site supports habitats that are locally common and widespread. A large horse grazed

field, a rough grassland field with dense scrub areas, a central woodland block and tree-

lined hedgerow and a mature tree line along the northern boundary, dominate the site.

4.2 Habitats of a local importance present on site include ‘The Village Green’ area of the site,

which supports species rich semi-improved neutral grassland with pockets of semi-

improved calcareous grassland and the River Wye that runs along the southern

boundary of the site.

4.3 The key habitat areas in terms of bat species are considered to be the northern site edge

and the small woodland block and tree-lined hedgerow running through the site. These

areas support a layering of habitats as well as shelter, which will be exploited by

numerous invertebrate species. The mature trees present within these areas are

considered to be associated with a diverse insect fauna, and as such these features are

used by foraging bats. The linear nature of these habitats is also considered important as

commuting routes for bats moving across the landscape.

4.4 The river corridor along the southern boundary of the site is also considered to be an

important habitat for bat species providing foraging habitat and a linear feature for

commuting. Although the rivers suitability as a commuting corridor is lessened by the

development at the western end reducing connectivity with built environment and

increased street lighting. Increased light levels from street lighting also affects the

southern bank of the river.



4.5 The garden habitats present along the eastern edge of the site also act as a linear feature

for bat species and indeed pipistrelle species were recorded using this area. Although a

very bright security light on the most southern house illuminated much of this area

during every survey visit.

Figure 9. Important green corridors and ecological linkages

4.6 The surveys revealed that the site is indeed used by bat species for both foraging and

commuting. Eight species in total were recorded using the site. Common and soprano

pipistrelle and noctule bats dominated activity. Occasional activity from brown long-

eared bats, serotine bats and myotis species and very occasional passes from Leisler’s bat

and nathusius pipistrelle was also recorded.

Ecological Enhancements & Recommendations

4.7 It is recommended that the major green corridors and habitat linkages such as the

northern tree line boundary, the central tree-lined hedgerow and the river corridor

should be retained and buffered within the scheme.



4.8 Hedgerows and boundary tree lines provide rich opportunities for invertebrates, which

provide important food resources for bats. As such these should be managed sensitively

to maintain and enhance their diversity.

4.9 The northern tree line, central woodland block and tree-lined hedgerow and river

corridor should be maintained as ‘dark corridors’, which provide protected and

enhanced corridors and green links through the site and into the local landscape. Dark

corridors are important for a range of species, including bats. The other linear features

such as the southern boundary of the ‘The Village Green’ and the eastern garden boundary

should also be subject to sensitive lighting.

4.10 The small woodland block and central tree lined hedgerow exhibited a large amount of

dead wood and brash piles. It is always recommended that dead wood be maintained on

the site and further habitat piles created. Dead wood is a valuable habitat for a range of

invertebrate species, which lay eggs within such features, allowing the larvae to feed

when developing.

4.11 A number of enhancements can be made to the final development to help reduce

potential ecological impacts. It is important to utilise native species of local provenance in

landscaping schemes to enhance the ecological value of a development.

4.12 Additional planting in places along the boundaries would augment the edges and

enhance its ecological value and help to patch up some gaps if present. A range of native

species may be suitable including spindle, privet, field maple, hazel and elder.

4.13 The use of wildflower mixes, sown into borders of footpaths and open green spaces will

enhance the ecological value of the site for a range of important invertebrates.

4.14 Installation of bat boxes will also enhance the number of roosting opportunities for bats

in the local area. Boxes should be hung on mature trees along the river edge, within the



northern boundary and on the edge of the existing woodland block on site and have clear

flight paths. Recommended boxes include:

• Schwegler 2F – This box simulates crevices inside to allow suitable habitats for

crevice-dwellers. Four of these boxes should be used on site.

• Schwegler 1FD – This box is a larger version of the 2F. Four of these boxes should be

used on site.

• Schwegler 1FW – This box is suitable for maternity or hibernation roosts. One of

these boxes should be used on site

Lighting

4.15 Bat species are light sensitive and artificial lighting can affect their behaviour and ability

to navigate across the landscape. A sensitive lighting scheme is recommended for the

site. It is advised that lighting is focused away from mature tree lines, the central tree-

lined hedgerow and the river corridor along the southern boundary keeping these areas

dark. Ground level lighting should be used within the internal road network. Lights

should be baffled in places to avoid excess light spillage.

4.16 Recommendations therefore for the lighting scheme include:

• Lighting should only be installed if there is a significant need;

• Light levels should be kept low, the use of low pressure sodium lamps or high

pressure sodium instead of mercury or metal halide lamps where glass glazing is

preferred due to its uv filtration characteristics;

• Lighting should be avoided near the treelines, with light angled away from these

areas, bats use linear features such as treelines to commute across the landscape to

forage; and

• Lights should have focussed luminance on their target area, preventing light spill

and pollution into other areas of the site and local area.



5.0 Conclusions

5.1 A total of eight bat species were recorded using the site for commuting and foraging

across the manned transect surveys and the Anabat Express Static recording. Activity

was dominated by common pipistrelles, soprano pipistrelles and noctule bat, three of the

most common UK bat species.

5.2 The main areas used by foraging and commuting bat species were the northern

boundary, the central woodland block and tree lined hedgerow and river corridor along

the southern boundary. Other linkages considered important were the southern

boundary for “The Village Green” area and the garden habitats along the eastern

boundary. These edges should be retained, buffered and enhanced throughout the

scheme to allow for the continued presence of bat species on site and allow them to move

with ease across the landscape.

5.3 Recommendations for enhancements have been made within this report, aimed at

improving the ecological value of the site post development. This includes the use of

native species in any planting scheme and the careful use of lighting. The installation of

nine bat boxes with mature trees around the site will also increase the number and types

of roosting opportunities within the site.

5.4 It is considered that if the enhancements and recommendations within this report are

followed then bat species will be able to use the site post development and the

favourable conservation status of bat species within the local area will remain unaffected



6.0 References

CIRIA C567 (2005) Working with wildlife – site guide. CIRIA, London.

Mitchell-Jones, A.J. (2004) Bat Mitigation Guidelines. English Nature, Peterborough.

Collins, J. (ed.) (2016) Bat surveys for professional ecologists: Good practice guidelines (3rd edn).

The Bat Conservation Trust, London.

Russ, J. (2012) British Bat Calls – A guide to species identification. Pelagic Publishing

Middleton, N. et al (2014) Social calls of the bats of Britain and Ireland. Pelagic Publishing

Internet resources:

Google Maps: www.maps.google.co.uk

Magic Interactive Map: www.magic.gov.uk



Appendix 1: Transect Activity Survey Results



The Ecology Partnership

297 Dorset House

Kingston Road

Leatherhead

KT22 7PL

Tel. 01372 824 205

www.ecologypartnership.com

Written by: Tom Rothero BSc (Hons) MSc MCIEEM

Senior Ecologist

Approved by: Alexia Tamblyn MA (Oxon) MSc CEnv MCIEEM FRGS

Managing Director & Principle Ecologist

Date: 19/12/2016

Transect & Static Activity Surveys For Bat Species€¦ · Slate Meadow – Bat Surveys December 2016 The Ecology Partnership Ltd 3 1.0 Introduction Background 1.1 The Ecology Partnership

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