Hameldon Hill Wind Farm Extension: Revised Addendum Bat Report€¦ · AECOM Hameldon Hill Wind...

Environment

RWE Npower Renewables November 2010

Hameldon Hill Wind Farm Extension: Revised Addendum Bat Report

Prepared by: .......................... Checked by: ........................................................................ Richard Wardle Catherine Johnson Principal Ecologist Senior Ecologist Approved by: ............................................................. Lorraine King Associate Director Hameldon Hill Wind Farm: Revised Addendum Bat Report

Rev No Comments Checked by Approved by

Date

0 Draft for internal checking RTW 28/11/10

1 Final report for issue RTW 29//11/10

5th Floor, 2 City Walk, Leeds, LS11 9AR Telephone: 0113 391 6800 Website: http://www.aecom.com Job No 60050933 Reference: Re03 Date Created November 2010 This document has been prepared by AECOM Limited for the sole use of our client (the “Client”) and in accordance with generally accepted consultancy principles, the budget for fees and the terms of reference agreed between AECOM Limited and the Client. Any information provided by third parties and referred to herein has not been checked or verified by AECOM Limited, unless otherwise expressly stated in the document. No third party may rely upon this document without the prior and express written agreement of AECOM Limited. document2

1 Introduction ....................................................................................................................................................................... 1

2 Consultations .................................................................................................................................................................... 2

3 Survey Methods and Rationale ........................................................................................................................................ 8

4 Results ............................................................................................................................................................................. 16

5 Discussion of Key Environmental Impacts ................................................................................................................... 29

6 References ....................................................................................................................................................................... 34

Figures 35

Appendix A: Consultee comments and written responses ..................................................................................................... 36

Appendix B: Survey Forms 2009 ................................................................................................................................................. 37

Appendix C: Survey Forms 2010 ................................................................................................................................................. 38

Appendix D: Bat Activity Figures 2009 ....................................................................................................................................... 39

Appendix E: Bat Activity Figures 2010 ....................................................................................................................................... 40

Appendix F: Revised Constraints Plan and Turbine Layout ..................................................................................................... 41

Appendix G: Turbine buffer drawings ........................................................................................................................................ 42

List of Tables Table 1: Value of features on site for bats ........................................................................................ Error! Bookmark not defined. Table 2: Summary of Listening Points and Habitat Types ................................................................ Error! Bookmark not defined. Table 3: Survey Details ..................................................................................................................... Error! Bookmark not defined. Table 4: Summary of Bat Activity Survey Results 2010 .................................................................... Error! Bookmark not defined. Table 5: Collision risk of bat species recorded at Hameldon Hill based upon Natural England 2009Error! Bookmark not defined.

Table of Contents

AECOM Hameldon Hill Wind Farm Extension: Revised Addendum Bat Report 1

Capabilities on project:

Environment

1.1 RWE Npower Renewables Ltd (RWE NRL) is proposing to construct, operate and decommission a three turbine

extension to the existing onshore wind farm, located at Hameldon Hill near Burnley in Lancashire.

1.2 A planning application was submitted to Burnley Borough Council (BBC) in December 2009 in accordance with the

Town and Planning Environmental Impact Assessment (EIA) Regulations, 1999. The regulations require for an EIA

to be carried out; and the results of the EIA to be included in an Environmental Statement (ES) to accompany the

planning application.

1.3 The Ecology chapter of the ES included an assessment of the potential impacts of the proposed wind farm

extension on the bat populations present at the site. The limitations of the surveys in 2009 were clearly

acknowledged in the ES, in that there was an insufficient spread of surveys across a full season of potential bat

activity, such that there was a relatively large degree of caution built in to the impact assessments and suggested

mitigation presented in the ES.

1.4 Following submission of the ES, this was recognised by Natural England (NE) and Lancashire County Council

(LCC), both of whom raised an objection to the proposal. This objection identified that there was insufficient

information accompanying the planning application from which to make a robust assessment of the potential

impacts on bats. It also noted the recorded presence noctule (Nyctalus noctula) and Nathusius’ pipistrelle

(Pipistrellus nathusii), which are two species that are perceived, in general, to be at high risk of collision with

rotating turbine blades, as set out in guidance published by Natural England (Mitchell-Jones and Carlin, 2009).

The consultees identified that the site should be investigated throughout the year, with survey effort spread across

the key periods of bat activity (i.e. April – October) in order to make a robust assessment of bat activity across the

site.

1.5 Further surveys were commissioned for 2010 in order that a sufficiently robust impact assessment could be made

and, if necessary, a suitable package of mitigation and/or compensation could be proposed and conditioned as part

of the planning approval. The surveys were undertaken between April and October 2010 and involved a series of

dusk and dawn transects and recordings using an automated recording device placed at a number of locations

within and close to the development area.

1.6 An additional report was submitted as an addendum to the ES with the aim of addressing the comments made on

the content of the original ES document’s bat assessment. A key aim was to investigate further whether noctule

and Nathusius’ pipistrelle are at high risk of collision with wind turbines at this site and what forms of mitigation

could be used to minimise any potential impacts, should the need arise.

1.7 Following a further consultation period in which NE and LCC reviewed the additional information presented against

the original ES submission, a meeting was held between RWE NRL, AECOM, NE, LCC and BBC. A number of

questions were raised about the information presented in the addendum report. These are summarised in Section

2 of this revised addendum report. This has necessitated further review of the survey data and survey methods.

This revealed a number of errors in the data presented that have inevitably confused the overall message of the ES

and the first addendum report. Furthermore, previous reports have not made clear the thought processes and

professional judgements made with respect to the bat populations recorded on the site and the methods employed

in their survey and assessment.

1.8 The aim of this revised addendum report is to address the concerns raised by the consultees, to correct any

misrepresentations of the survey results and provide more in depth justification, greater clarity and consistency of

presentation to the survey methodologies employed, and the baseline survey data. Following on from this, the

impact assessments and the information presented herein have been revised as appropriate. Revisions have also

been made to the mitigation proposed such that it is backed up by a clearer understanding of the survey data and a

better understanding of the likely impacts of the proposed wind farm.

1 Introduction



Environment

1.9 The purpose of this section is to set out the consultation process and to summarise the comments made by NE and

LCC. This will provide a contextual background against which the revised survey methods, baseline data,

analyses, impact assessments and mitigation proposals presented herein can be set out.

1.10 The consultation process has occurred in several stages, notably following submission of the ES and latterly

following submission of an addendum bat report. Table 2.1 shows the key stages in the planning process and the

activities associated with them, starting with the original commission of bat surveys in 2009, and summarising the

key comments made by NE and LCC at each consultation stage. Copies of consultee responses received in

writing are provided in Appendix A.

1.11 The methods employed and findings of each round of bat surveys (first in 2009, then in 2010) and the impact

assessments based on the data are summarised in Table 2.1 to provide context to the consultee comments. More

detailed presentation and discussion of these are given in subsequent sections.

1.12 The scope of this revised addendum report is therefore to address the comments and concerns raised by NE and

LCC. The report therefore must satisfy a number of key objectives:

• Address and correct any misrepresentations of the survey data from previous submissions.

• Provide greater consistency and continuity between the ES and the Addendum Bat Report such that all survey

methods employed, baseline data, impact assessments, mitigation proposals and the revisions made to them

are clearly presented in a single document.

• Provide revised analyses of the data and clearer judgement on the way in which the site is used by bats.

• Provide more robust impact assessments and revised mitigation proposals as necessary.

2 Consultations



Environment

Table 2.1: Planning process time line and consultee response summary

Date(s) Action/occurrence Outcomes Notes/Comments

September

2009

RWE NRL

commission

AECOM to carry out

bat surveys as part

of a wider EIA

process

September

– October

2009

AECOM carry out

data search and bat

surveys

Baseline data AECOM complete ES, including impact assessments and recommendations for mitigation.

December

2009

AECOM complete

ES. Submission of

planning application

and ES to BBC

BBC forward ES

to consultees

Key findings:

Dry stone walls that cross the site, Thorny Bank Wood and Tower Brook identified as being of high value as

corridors for commuting and foraging bats. However further surveys reveal Tower Brook to be relatively

disturbed, subjected to intensive grazing and species-poor, therefore of limited value as a feeding resource.

A series of transects carried out to cover linear structure habitats, open spaces and turbine locations. Anabat

left on site, both close to the northern end of Tower Brook (Turbine 1) and the southern end of Tower Brook

(Turbines 2 and 3) on three occasions.

Turbine 1 identified as high-risk because of its relative proximity to Tower Brook and the possibility that this

may be used as a flight line by foraging and commuting bats, including Nathusius’ pipistrelle. However only

common pipistrelle recorded here.

Turbines 2 and 3 perceived as lower risk due to the perceived use of specific habitat features as flight lines

and the stand off between these and the proposed turbine locations. However Anabat recordings of

Nathusius’ pipistrelle and Noctule from the area around the southern end of Tower Brook and the dry stone

wall that crosses it.

Cautious impact assessments for collision and barotrauma-related mortality of high risk species (noctule and

Nathusius’ pipistrelle) of Large adverse, Slight adverse for common pipistrelle.

December

2009 –

February

2010

Consultation period Consultation

responses

received by BBC,

forwarded to RWE

NRL and AECOM

Comments from NE (16/02/2010, Appendix A):

Common pipistrelle (Pipistrellus pipistrellus), noctule and Nathusius’ pipistrelle were recorded during surveys,

the latter two on Anabat only.

Data collected from a suboptimal survey period and it is difficult to evaluate the bat assemblages recorded in

the survey area.......as it is unknown if the [bat] populations are regularly occurring.

Surveys should follow advice in Natural England Technical Information Note TIN059 as follows:



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• Focus survey effort on the periods when highest concentrations of bats are likely (April – October)

• Surveys may span more than one year

• Survey effort should be distributed as above. A rough guide would be at least 1 survey per month

and/or use of remote detectors

• In high risk situations more effort is required, which may mean more survey visits or increased use of

remote detectors for longer periods

There is therefore insufficient information in the planning application to fully ascertain the impacts of the

proposed development on bats. Such protected species are a material consideration in planning terms

therefore impacts must be established before planning permission can be granted.

Where a development affects a species protected under the Conservation (Natural Habitats, &c) Regulations,

Regulation 44, three criteria must be satisfied:

• The development must be of overriding public importance, for preserving public health or public safety

and other conditions of overriding public interest

• There must be no satisfactory alternative

• The actions authorised will not be detrimental to the maintenance of the population of the species

concerned at a favourable conservation status in their natural range.

Comments from LCC (21/01/2010, Appendix A):

Bats have been identified as being present however insufficient survey effort has been carried out to assess

the potential impacts of the proposal on them. The ES identified that it was only possible to cautiously

assess the impacts of the proposal on bats because:

• Surveys were carried out at a suboptimal time of year

• Bat assemblages could not be evaluated as roosts were not identified and it is not known if the

populations are regularly occurring.

Reference to the standards for bat surveys outlined in TIN059.

Reference to the conclusions of the ES:

• The bat species recorded are at high risk of turbine impact, with associated risk to populations

• Even with mitigation, collision impacts on high risk species would be large and adverse

With the three criteria shown above, information in the ES suggests the third criterion would not be met by

the proposals.

Recommendations for a method statement, which is likely to require further survey to inform it properly.

March 2010 RWE NRL

commission

AECOM to carry out

round 2 surveys



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April -

October

2010

AECOM carry out

additional surveys

in line with guidance

in NE and Bat

Conservation Trust

Guidance

Further baseline

data

October

2010

AECOM produce

addendum bat

report

RWE NRL submit

addendum bat

report to BBC

Further transect surveys, including dusk and dawn transects, plus extended dusk transects to cover late

evening activity.

Anabat left at various positions around the southern end of Tower Brook throughout the activity season to

investigate further the use of this area by Nathusius’ pipistrelle.

Common and soprano pipistrelle (Pipistrellus pygmaeus) recorded on transect surveys mainly foraging close

to Thorny Bank Wood. Occasional Myotis records. Very few flights of any species across open spaces.

Anabat records include these species plus Nathusius pipistrelle in the southern half of the site, close to a dry

stone wall and the southern end of Tower Brook. This indicates a regularly occurring population of these

species in this area. Noctule not recorded on any surveys, indicating that this species is not regularly

occurring.

Impact assessments for collision of Nathusius’ pipistrelle indicate that southern end of the site is higher risk

for this species.

Cautious approach to wind farm design already included buffers around woodland, hedgerows and dry stone

walls that exceed recommendations in NE TIN051.

Acknowledgement of additional risk and some uncertainty around the impacts of T3 on Nathusius’ pipistrelle.

Additional mitigation proposals for discussion with consultees: monitoring, micro-siting and re-alignment of

dry stone wall south of T3 in line with larger buffer in Eurobats guidance (Rodriguez et al., 2008)

October -

November

2010

BBC forward

addendum report to

consultees

Consultation

review. Initial

comments

received from NE

Initial comments from NE (email in Appendix A):

Conservation and avoidance measures should be explored before any mitigation or compensation is

proposed.

There is no real summation of Nathusius’ pipistrelle numbers, analysis of Nathusius’ activity on site does not

show how much activity was recorded.

Has there been any monitoring of the existing turbines for bat activity or was there any information submitted

with the planning application for the existing turbines?

Can the “problem” turbine (T3) be moved out of the way of bat activity here? Moving the dry stone wall may

or may not be effective at directing bats away from the turbine.



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What proposals do AECOM/RWE NRL have for further monitoring? Monitoring during and post-construction

would be useful. There would need to be a clear strategy to deal with any impacts associated with the

turbines, should they be detected during monitoring.

November

2010

Meeting between

RWE NRL,

AECOM, BBC, NE

and LCC

Further comments

to be addressed

Comments from NE and LCC:

The addendum bat report is not clear and did not adequately link the findings of the 2009 surveys presented

in the ES to those of the 2010 surveys.

Data from recording devices are missing from both 2009 and 2010.

The ES in 2009 identified Tower Brook as a high value landscape feature for foraging and commuting bats,

but this has not been explored further in 2010 with the position of T1 at the northern end of the brook –

Anabat was mostly near T3 and T2 in 2010 and sometimes placed within the quarry further south of these

turbines. There does not appear to be enough repeat recordings using Anabat in the northern half of the site,

nor was Anabat placed at the location of each turbine.

Records of Nathusius’ pipistrelle were exclusively from Anabat recordings, therefore can the consultant be

confident that the combination of Anabat and transect surveys are adequate to provide sufficient data to

inform the impact assessments and mitigation?

There might not be enough data at T1 to assess the impact here. This needs clarification.

The suggestion to move the dry stone wall away from T3 such that the buffer here is in line with Eurobats

guidance (Rodriguez et al., 2008) implies that there is enough bat activity here to be a significant problem.

This has not been explained adequately in the addendum report, neither is there sufficient justification for the

mitigation proposed here.

The report needs to be much clearer in terms of how the mitigation proposed is specific to the potential

impacts of the turbines, particularly T3. For mitigation to be robust, it is necessary to know what you are

mitigating for and this should be informed by the survey data. It is not clear from the report if this has been

addressed properly.

There is a need to demonstrate that the proposal meets all 3 criteria under the Conservation (Natural

Habitats, &c) Regulations, Regulation 44, for developments that affect a species protected under the

Regulations. The report therefore needs to show greater confidence in the results, if possible, and

justification for the mitigation proposed.

The buffer around watercourses is only 30m, which does not appear to be sufficient to meet the minimum

requirement in NE guidance TIN051. This raises additional concern with the apparent lack of survey effort at

the northern end of Tower Brook and the location of T1.

November

2010

Teleconference

between all parties

above, including

AECOM bat

Agreement to

revise addendum

bat report with

greater clarity and



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specialist, to clarify

survey results,

justify methods and

mitigation.

more information.

Review of

baseline data by

AECOM

Revisions to

addendum report

TBC AECOM and RWE

NRL submit revised

addendum report to

BBC, NE and LCC

TBC



Environment

Habitat Assessment

3.1 On 22 September 2009 a bat habitat assessment was undertaken. The survey aim was to identify and record

features within the survey area, or in the landscape, and their potential value for use by bats for roosting, foraging

or commuting. The results of the habitat assessment were used to inform the design of the transect survey and to

identify vantage points, taking into account the proposed locations of the new wind turbines.

3.2 Each feature identified was assigned a level of bat potential: high, medium or low (as per Table 3.1).

Table 3.1 –Value of features on site for bats

Feature Location Value Level

Traditional stone built farm buildings

Wider landscape Summer roosting and hibernation

High

Stone Walls Site Commuting High

Acid grassland Site Foraging Medium

Improved grassland (open) Site Foraging Low - Medium Water course (Tower Brook)

Site & wider landscape

Foraging and commuting

High

Wooded valley (Thorny Bank Clough/Wood)

Site Foraging, roosting and commuting

High

Community plantation woodland <10 years old.

Site Foraging and commuting.

Medium

Open Water Site Foraging High

3.3 The habitat within the survey area included broadleaved woodland, scrub, acid grassland, open standing water,

flowing water, linear features (field boundaries including fences and dry stone walls). The site as a whole therefore

includes habitats with high potential for roosting, foraging and commuting bats. The site is also connected with the

wider landscape by linear features that could be used by commuting bats i.e. stone walls, lines of trees and scrub

and a body of flowing water.

3.4 The wider landscape also contains traditional stone buildings which contain features of particular significance for

roosting bats.

Selection of Vantage Points and Transects

3.5 The transect route and vantage points (VP) shown on Figure 3.1 were chosen in order to cover all high potential

habitats on site. Each vantage point was a distance of between 40 m and <300 m away from any given proposed

location of wind turbine. The listening points are summarised in Table 3.2.

Table 3.2. Summary of Vantage Points and Habitat Types

Vantage Point Habitats

1 - 2 Acid grassland Dry stone walls Tower Brook

2 - 3 Acid grassland Dry stone walls Hawthorn scrub Thorny Bank Woodland edge

3 – 4 Acid grassland Hawthorn scrub Thorny Bank Woodland edge

4 – 5 Thorny Bank Woodland Broadleaved Plantation Woodland < 10 years

3 Survey Methods and Rationale



Environment

Vantage Point Habitats Tower Brook

5 – 6 Thorny Bank Woodland Broadleaved Plantation Woodland < 10 years Tower Brook

6 – 7 Open water (farm pond) Acid grassland Dry stone Walls

7 - 8 Acid grassland

8 – 9 Acid grassland Dry stone Walls

9 - 10 Acid grassland Dry stone Walls Edge of discussed quarry

10 – 1 Acid grassland Tower Brook Edge of discussed quarry

Anabat Recordings

3.6 The Anabat was set to begin recording from approximately 30 minutes before sunset until shortly after sunrise on

two separate occasions in 2009. In 2010, further recordings were made using Anabat at these locations, plus an

additional location. Anabat was used on a number of dates in 2010, and was left on site on all but one of the

transect dates in 2010. It was also left to record for 3 consecutive nights between 28th September and 1

st October

2010, in order to provide a larger data set and, since the surveys in 2009 were carried out only in September and

October, to analyse the consistency of autumnal bat activity between years.

3.7 The Anabat locations are marked as follows (in order from north to south) on Figure 3.2

• Location A: was used in 2009 only and was situated at the northern end of Thorny Bank Wood, close to the

farm pond and Tower Brook.

• Location B: where noctule and Nathusius’ pipistrelle had been recorded in 2009. This was at the base of the

dry stone wall that crosses the southern end of Tower Brook, between vantage points 2 and 10.

• Location C: situated at the south of the site, in the bottom of the disused quarry, in an area that was difficult to

reach during night surveys. Approximately 150 m south east of location B.

Transect Surveys in 2009

3.8 The site was first surveyed on 22nd September 2009. Subsequent surveys were carried out during October when

night-time temperatures were >8oC and weather conditions were deemed suitable for bat activity.

3.9 Dusk/night time transects were walked from 15 minutes prior to sunset until completion (approximately two hours

after sunset). Dawn transects commenced approximately two hours before sunrise and continued until completion.

The foraging period was typically curtailed by rapidly decreasing temperatures by about two hours after sunset.

Therefore the timings of the surveys adequately covered the likely bat emergence, re-entry and peak periods of

foraging activity when invertebrate prey was most abundant.

3.10 The starting point of the transect route was alternated between different vantage points on each survey. This

approach helps to provide more detailed information on the distribution of bat activity across the site at different

times of the night. It can also help to identify the potential direction of bats commuting from or to roosts.



Environment

3.11 Stops were made for five minutes at each vantage point, during which time all bat activity was recorded.

Recording was carried out continuously such that bats active in locations between the vantage points could be

detected and identified.

3.12 Bat calls were monitored/recorded using a Batbox Duet frequency division bat detector with a suitable MP3

recording device. Locations of recorded bat activity were noted on a map along with the possible species and its

behaviour. The MP3 track number associated with each call was recorded carefully so that MP3 recordings could

later be analysed in accordance with the notes recorded on site. Recorded bat calls were subsequently analysed

using BatSound software to identify bats to species level.

Transect Surveys in 2010

3.13 Transects and listening points used in 2010 were identical to those used in 2009. However in 2010 the number of

bat passes was recorded to enable the intensity of bat activity to be determined for different parts of the site, such

that the relative importance of the different habitats could be determined. Note that this does not provide useful

data on the numbers of bats present, which was determined through the general observations recorded on survey

forms.

3.14 The main objective of the surveys in 2010 was to cover different stages of bat activity throughout the year

including:

• Commuting between post hibernation roosts;

• Spring migration;

• Local population activity: flight lines, foraging and high flying species;

• Autumn migration.

3.15 Between April and May, and in September, dusk/night time transects were walked, with the aim to start from 15

minutes prior to sunset for approximately two hours after sunset. Dawn transects were also programmed to occur

between June and August, commencing approximately two hours before sunrise and continuing until completion.

However poor weather conditions in July and August meant that only 1 dawn survey was carried out. The survey

schedule was therefore adjusted so that, between June and September, dusk/night time transects were walked

from up to15 minutes prior to sunset until approximately four hours after sunset, which typically allowed the transect

route to be covered twice in 1 night. The intended benefit of this was that it would enable any activity late in the

evening to be detected. Dawn records were obtained during this period from Anabat recordings.

3.16 The timings of the surveys adequately covered the likely bat emergence, re-entry and peak periods of foraging

activity when invertebrate prey was most abundant. Also longer dusk/night surveys were included during the spring

and autumn months because they are more likely to pick up migration activity. Surveys were started after sunset

on two occasions (3rd

June and 28th

September) due to unforeseen circumstances beyond the surveyors’ control.

3.17 Information on the distribution of bat activity across the site at different times of the night was noted to identify the

potential direction of bats commuting from or to roosts. During the surveys conducted on the 22nd

June and 24th

August an additional transect along the access track to the north of the site was monitored approximately 30

minutes prior to sunset in order to pick up any emergence activity. This area was monitored at sunrise during the

survey conducted on the 23rd

June to pick up any swarming or returning activity in the farm buildings adjacent to

the track. This also enabled the potential impacts of the access track to be assessed on any flight lines here.

3.18 Stops were made for five minutes at each vantage point, during which time all bat activity was recorded.

3.19 Bat calls were monitored/recorded using a Bat Box Duet frequency division bat detector with a suitable MP3

recording device. Locations of recorded bat activity were noted on a map along with the possible species and its



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behaviour. The MP3 track number associated with each call was recorded carefully so that MP3 recordings could

later be analysed in accordance with the notes recorded on site. Recorded bat calls were subsequently analysed

using Bat Sound software to identify bats to species level.

Summary of bat survey methods in 2009-10

3.20 Tables 3.3 and 3.4 summarise dates, times and methods used on all bat surveys from September 2009 through to

October 2010.

Table 3.3. Details of all transect surveys

Date Sunset/Rise Survey

Times

Weather Conditions

2009

22/09/09 19.05 19.05 –

21.22

Clear and dry, 12oC, wind speed 7km/h

23/09/09 06.55 04.27 -

06.55

Light intermittent rain, 11.5oC, wind speed 9 km/h

05/10/09 18.40 18.05 –

20.45

8.5oC, dry, light breeze

14/10/09 18.15 18.15 – not

recorded

Overcast, calm, low cloud. 14oC.

15/10/09 07.35 05.15 – not

recorded

Low cloud and poor visibility. Only part of the transect was walked

due to unsuitable weather conditions.

15/10/09 18.13 18.00 – not

recorded

Calm. Drizzle just before the start of the survey. 14oC.

2010

29/04/10 20.30 20.10-23.00 Overcast, westerly breeze 3mph, 7

oC and light rain at the start of

survey, 7oC and dry at the end.

27/05/10 21.15 20.45 –

22.30

Overcast, westerly breeze 1 - 5mph, 8oC and dry at the start of

survey, 6oC and heavy rain at the end.

3/06/10 21.33 21.20 –

00.50

Clear, dry and 3mph wind. Temperature 18 o

C at the start of the

survey and 14 oC at the end.

14/06/10 21.30 21.00 –

23.30

Overcast, dry and 1mph wind. Temperature 10 o

C at the start of and

14 o

C at the end of the survey.

22/06/10 21.43 22.15 –

00.29

Overcast, westerly breeze, 20oC at the start of survey and 16

oC at

the end.

23/06/10 04.39 02.10 –

04.20

Overcast, westerly breeze. 11oC at the start of the survey and 12

oC

at the end.

24/08/10 20.15

20.20 –

23.58 Light – moderate westerly wind, overcast. 14

oC at the start of the

survey.



Environment

Date Sunset/Rise Survey

Times

Weather Conditions

(dusk + 4

hours)

28/09/10 18.51

19.30 –

22.53

(dusk + 4

hours)

Overcast, easterly breeze 3mph turning to southerly 5mph. 14oC,

dry at the start of survey and light rain at the end.

Table 3.4. Dates of all Anabat Surveys

Date(s) Anabat Location (see figure 3.2)

22 – 23/09/09 B

05 – 06/10/09 A

27 – 28/05/10 B

03 – 04/06/10 B

14 – 15/06/10 B

22 – 23/06/10 C

24 – 25/08/10 C

28/09/10 – 01/10/10 B

Rationale for Survey Methods

3.21 The following paragraphs provide a justification for the survey methods used and the focus of the surveys on high

risk species across certain parts of the site. This necessitates some brief discussion of the survey results. A

detailed presentation of the survey results is provided in Section 4.

3.22 Natural England advice (Technical Information Note TIN051 – Bats and Onshore wind turbines Interim

Guidance) on the surveying of proposed wind turbines is that until all evidence on impacts on bat populations

caused by these developments is available they are unable to recommend prescriptive guidelines for surveys. The

necessity is to determine whether bat species on site will be maintained in favourable condition status. This was a

general consideration in the choice and focus of survey methods employed at Hameldon Hill.

Area of Survey Focus in 2010

3.23 The 2009 surveys were conducted at a suboptimal time of year and were therefore insufficient to understand fully

the bat activity and usage of the site throughout the year. However they contributed significantly to the primary

objective of determining whether Hameldon Hill was used by, or was likely to be used by bats at any time of the

year.

3.24 The results from data collected in 2009 confirmed that bat activity was concentrated primarily on the western edge

of the site. Common pipistrelle (Pipistrellus pipistrellus) was the only regularly recorded species; however it was

present in relatively low numbers of no more than 3-4 individuals.



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3.25 Nathusius’ pipistrelle and Noctule were detected by Anabat only in the southern section of the site. There were no

Anabat records for these species in the northern part of the site, at the northern end of Tower Brook or Thorny

Bank Wood.

3.26 Natural England’s Technical Information Note TIN051 states that survey efforts should focus on significant

concentrations of bats and particular high risk species. The survey focus therefore was mainly on detecting

Nathusius’ pipistrelle and Noctule.

3.27 The 2009 data did not highlight significant numbers of any bat species present on the site. In order to monitor

Nathusius’ pipistrelle activity on site effectively, and taking into consideration constraints and limitations on the

availability of remote recording equipment, it was determined that the best location for the Anabat would be in the

area where the species was recorded in 2009, in the southern end of the site. The Bat Conservation Trust Survey

Guidelines (2007) state that:

“Automated systems placed in the open can supplement transect surveys and indicate whether results are representative of activity at other parts of larger sites.”

3.28 This advice was used to support the theory that by placing the device in this location, where a positive

identification had previously been obtained, the species presence and activity could be monitored on site

throughout the active period April – October. The transect surveys would be recorded using frequency division and

calls analysed using Batsound software. If Nathusius’ pipistrelle was recorded during transects then the use of

Anabat would be reviewed.

3.29 Observations regarding the general character of the site were also used to guide the focus of all surveys. The site

is cold, exposed and subject to intensive grazing on its lower slopes, mostly to the north of Anabat location B,

which supports almost exclusively improved and occasionally rush-dominated improved grassland. South of

Anabat location B the site is generally wetter and subject to less intensive grazing. Here it supports very young

plantation woodland and wet acid grassland. In habitat terms, the site is divisible into areas of differing potential to

support bats:

• The linear woodland that forms Thorny Bank Wood, flanking Thorny Bank Clough provides high quality

foraging along the western site edge.

• The upper slopes of the southern part of the site, to the south of Turbines 2 and 3, support wet acid grassland

and young plantation that could be regarded as a good foraging resource for bats.

• The lower fields that flank Tower Brook across the northern part of the site support improved grassland that is

heavily grazed and cattle puddled. These parts of the site are of much lower habitat value for foraging bats,

and this undermines the potentially high quality of Tower Brook Gulley as a foraging resource.

• Thorny Bank Wood, Tower Brook Gulley and the dry stone walls that cross the site represent potential flight

lines for bats, regardless of their potential as foraging resources.

Rationale for Transects

3.30 The transects used in 2010 replicated the 2009 surveys. The reasons for consistency of the route were:

• Data would be directly comparable with 2009 results.

• Consideration of the surveyors’ Health & Safety, based on the following general observations of the site made

over the course of the habitat assessment and subsequent surveys:

• Ground conditions in many areas consisted of wet ground, purple moor grass tussocks and cattle puddled

ground which made it difficult to walk across the site safely in conditions of darkness.



Environment

• The site is exposed and experiences rapidly changing weather conditions. Low cloud, thick mists and fogs

developing during the night were not uncommon.

• The sporadic presence of other people on site included the patrolling of the site by the gamekeeper. Therefore

transect routes were designed to ensure that surveyors would be more visible.

• Cattle were present often in large numbers in the central part of the site.

3.31 Transects excluded walking along the edges of Tower Brook in a north – south direction for reasons of health and

safety; the brook flows through a deeply cut, very steep sided gulley that attains a depth of around 10m in places

and this presents a significant hazard to surveyors in conditions of darkness. It was also determined, based on the

general observations outlined in paragraph 3.29, that Tower Brook was a lower quality habitat than had previously

been expected based on the initial site visit in 2009.

Rationale for Focus on Nathusius’ pipistrelle

3.32 Myotis species, common and soprano pipistrelle are easily detected using heterodyne and frequency division bat

detectors. Similarly noctule bats are detected easily using these methods in conjunction with Anabat. The focus of

Anabat surveys were therefore deliberately targeted at Nathusius’ pipistrelle.

3.33 Typical foraging habitat for Nathusius’ pipistrelle consists of woodland areas, especially rides and paths. The

species also favours the edges of lakes and water bodies adjacent to the cover of a woodland edge. Its diet

consists mainly of aquatic Diptera i.e. Chironomids. The following general observations about the biology of

Nathusius’ pipistrelle can also be made:

• Summer roosts are commonly in tree holes, bat boxes and crevices but rarely in buildings. The species tends to

avoid disturbed human settlement.

• Nathusisus’ pipistrelle generally has an earlier breeding season then other pipistrelles in the UK and mates

between July and September. This potentially would result in changes to activity on site during these months

that would not be observed in other species until later in the year.

• Nathusius’ pipistrelle forages typically at heights of 4 m – 15 m around woodland edge canopy adjacent to

water bodies.

3.34 Therefore the bats were most likely to forage and commute along the western edge of the site, particularly in wet

areas. However Nathusius’ pipistrelle was not identified or recorded on frequency division north of Tower Brook or

on Anabat, in the pond area. This is a location where foraging activity would have been expected according to

what is known about the species’ habitat preferences and general behaviour.

3.35 Casual observations also noted that although a high intensity of bat passes was recorded here (at VP6) there were

only approximately 2 – 3, and certainly fewer than 5, individual common and soprano pipistrelle bats foraging at

any one time in this area.

3.36 The northern section of Tower brook is exposed and the general observations made about the site and its use by

bats were used as a guide to focus on the activity of Nathusius’ pipistrelle across the southern part of the site

around the southern part of Tower Brook and the dry stone wall that crosses it here.

3.37 Nathusius’ pipistrelle was not recorded on frequency division close to Anabat locations A and B probably because

the bats are in low density here. The transect route deviates away from Anabat location A in particular.

3.38 The Anabat was placed in location C in June and August 2010, approximately 150m south-east of location B, to

challenge the theory that the bats were commuting from the south east of the site. As only two records were

obtained during these recordings for June in the first half of the night it was determined that this was not the case

and the foraging bat had reached the limit of its feeding range.



Environment



Environment

4.1 This section draws together the results of all surveys carried out in 2009 and 2010 in order to inform the impact

assessments and mitigation put forward in subsequent sections of this report. Completed survey forms are

provided as Appendices B and C for 2009 and 2010 respectively. Figures showing the locations of the bats

recorded, where this could be determined, are included in Appendices D and E for 2009 and 2010 respectively.

4.2 The survey results presented for both survey years are taken directly from the ES and the addendum report

submitted in October 2010, with additional narrative added where appropriate. Tables 4.1 and 4.2 summarise the

results of the transect surveys in 2009 and 2010 respectively.

Table 4.1: Summary of transect data 2009

Time observed

Location of bat/ comments

Species Behaviour (emerging/foraging etc.)

Number of bats

22/09/09 - Dusk

19.42 Close to VP4 on the

edge of Thorny Bank

Wood

Common

Pipistrelle

Foraging 1

19.48-

19.53

VP5 Common

Pipistrelle

Foraging 2

19.55 Concentrated feeding

along woodland edge

and interior

Common

Pipistrelle

Foraging 2

19.57 Heard but not seen Common

Pipistrelle

Commuting 1

19.59 Several passes and

feeding buzzes of

individuals feeding in

woodland

Common

Pipistrelle

Commuting and foraging 1

20.03-

20.08

VP6 – concentrated

feeding along

woodland edge and

interior

Common

Pipistrelle

Foraging 1

20.10 Several passes of a

single individual

Common

Pipistrelle

Commuting 1


Pipistrelle

Commuting 1

21.20 Foraging along conifer

hedge of access track

Common

Pipistrelle

Foraging 1

23/09/09 - Dawn


Pipistrelle

Commuting 1

05.39-

05.44

VP6 – concentrated

feeding along

Common

Pipistrelle

Foraging 1

4 Results



Environment

Time observed



Number of bats

woodland edge

05.48 Concentrated feeding

along woodland edge

and interior

Common

Pipistrelle

Foraging 2

05.51-

05.56

VP5 - Foraging along

woodland edge

Common

Pipistrelle

Foraging 1

05.59 Foraging along

woodland edge

Common

Pipistrelle

Foraging 1

06.04-

06.09

VP4 - Foraging along

woodland edge

Common

Pipistrelle

Foraging 1


Pipistrelle

Commuting 1

05/10/09 - Dusk

19.25 In gulley of Tower

Brook

Common

Pipistrelle

Foraging 1

20.20 Track near farm Common

Pipistrelle

Foraging 1

20.23 Farm Common

Pipistrelle

Foraging 1

14/10/09 – Dusk


Pipistrelle

Foraging 1

19.00 –

19.05

VP7 Common

Pipistrelle

Foraging 1

- VP8 Common

Pipistrelle

Foraging 1

- Between VP8 and 9 Common

Pipistrelle

Foraging 1

- VP9 Common

Pipistrelle

Foraging 1

- In gulley of Tower

Brook

Common

Pipistrelle

Commuting 1

19.52 –

19.57

VP1 Common

Pipistrelle

Commuting 1

20.48 –

20.53

VP7 Common

Pipistrelle

Foraging 1

15/10/09 – Dawn



Environment

Time observed



Number of bats

No bats recorded

15/10/09 - Dusk

18.40-

18.45

Between VP2 and 3 Common

Pipistrelle

Foraging 1

18.50-

18.55

Between VP1 and 2 Common

Pipistrelle

Foraging 1

19.10-

19.15

VP2 Common

Pipistrelle

Foraging 1

19.25-

19.30

VP4 Common

Pipistrelle

Foraging 1

- Between VP4 and 5 Common

Pipistrelle

Foraging 1

19.35-

19.40

VP5 Common

Pipistrelle

Foraging 1

19.42-

19.47

VP6 Common

Pipistrelle

Foraging 1

19.52-

19.57

VP7 Common

Pipistrelle

Foraging 1


Pipistrelle

Foraging 1

Table 4.2: Summary of Transect Data 2010

Time observed

Location of bat/

comments Species

Behaviour (emerging/foraging

etc.)

Number of bat

passes

Number of bats

29/04/10 – Dusk + 4 hours

21.06 VP4 Common

pipistrelle Commuting (not seen) 1 1

21.14 –

21.16

Between VP4

and VP5

Common

pipistrelle

Foraging in Thorny Bank

wood. - 1

21.21 Between VP4

and VP5

Common

pipistrelle


wood. - 1

21.23 Between VP4

and VP5

Common

pipistrelle


wood. - 2

21.25 VP5 Common

pipistrelle


wood. 10+ 2



Environment

Time observed

Location of bat/

comments Species


etc.)

Number of bat

passes

Number of bats

21.31 VP6

Common

pipistrelle

Foraging around the

pond area. 10+ 2

Myotis sp. Foraging in Thorny Bank

wood. - 1

27/05/10 – Dusk

No bats heard. Survey terminated at 22.30 LP5 due to heavy rain.

3/06/10 – Dusk + 31/2

hours

22.06 Between VP5

and VP6.

Common

pipistrelle Commuting - 1

22.11 VP6 Common


2216 Between VP6

and VP7

Common

pipistrelle Foraging - 1

23.14 VP3 Common


23.28 Between VP4

and VP5

Common


23.38 BetweenVLP4

and VP5.

Common


23.52 VP7 Common


14/06/10 – Dusk

22.23 VP5 Common


22.29 VP6 Common

pipistrelle

Foraging around the

pond area. - 1

22.31 VP6 Daubentons’ Foraging west in woods. - 1

22.47 VP7 Common

pipistrelle

Flying in an east/west

direction along stone

wall

- 1

22/06/10 – Dusk

22.44 VP2 (west) Common

Pipistrelle Foraging 1

23.02 –

23.05

Between VP3

and VP4. Edge

of Thorny Bank

Common

pipistrelle Foraging 9 1



Environment

Time observed

Location of bat/

comments Species


etc.)

Number of bat

passes

Number of bats

Wood

23.15 VP4 Common


23.18 VP5 Common


23.29

Between VP5

and VP6. Edge

of woodland.

Common


23.31 VP6

Common &

Soprano

pipistrelle

Foraging 55 2

23.37

Between VP6

and VP7 (bats

over pond

area).

Common


23.43

BetweenVLP6

and VP7 track

and grazing

pasture.

Common


00.22 VP10 – along

stonewall.

Common


23/06/10 – dawn

02.15 VP6 Common


02.20 BetweenVLP6

and VP5

Common


02.27 VP5 – along

woodland edge

Common


02.30 VP5 – along

woodland edge Myotis sp. Foraging 1 1

02.32

Between VP5

and VP4 –

along

woodland

edge.

Common


03.00 VP9 – along

stonewall

Common

pipistrelle Commute west to east 1 1



Environment

Time observed

Location of bat/

comments Species


etc.)

Number of bat

passes

Number of bats

24/08/10 – dusk + 4 hours

20.43

Between VP3

and VP4 –

woodland

edge.

Common


21.05

VP5 –

woodland

edge.

Common


21.10 –

21.11

Between VP5

and VP6 –

woodland

edge.

Common


21.14 –

21.16

VP6 – around

pond

Common


21.32 –

21.34

BetweenVLP6

and VP7 –

around pond

area

Common


23.12 VP9 – along

stonewall

Common

pipistrelle

Commuting east to

west. 1 1

23.48 –

23.53 VP6

Common


28/09/10 – dusk +4 hours

19.41 Between VP1

and VP2

Common

pipistrelle Commuting but not seen 1 1

19.44 –

19.50 VP2

Common


20.02 Between VP3

and VP4

Common


20.08 VP4 –

woodland edge

Common &

Soprano

pipistrelle

Foraging 50 <5

20.17

VP5 – along

woodland

edge.

Common

pipistrelle Not seen 1 1

20.30 VP6 Common




Environment

Time observed

Location of bat/

comments Species


etc.)

Number of bat

passes

Number of bats

20.44 Between VP6

and VP7.

Common

pipistrelle

Flew over site but not

seen 1 1

22.00

Between VP3

and VP4 –

along

woodland

edge.

Common

pipistrelle Foraging in the distance 3 1

22.03 VP4 Common

pipistrelle

Commute along

woodland edge. 1 1

22.09

Between VP4

and VP5 –

along

woodland

edge.

Common

pipistrelle Foraging 10+ <3

Survey Results 2009

4.3 Common pipistrelle was the only species of bat recorded within the survey area during the transect surveys

although additional species were identified from Anabat data.

4.4 Small numbers of bats were recorded across the whole site, almost exclusively adjacent to tree lines, dry stone

walls or other linear features. Very few bats were recorded foraging or commuting over open habitats. It was also

noted that bat activity was greatest around the structure habitats such as woodland areas, dry stone walls and

hedgerows linking potential feeding habitats.

4.5 The majority of bat activity was recorded from close to or above Thorny Bank Wood. In general, bat activity was

greatest within the western boundary of the survey area away from the location of the existing turbines. This area

was also closest to the farm buildings to the north and west of the site which could provide possible roosting

habitat.

4.6 Common pipistrelle activity was also recorded on a number of occasions along the access track leading to the site.

The access track is bordered in part by a tall hedgerow often used by bats for the purpose of commuting. The track

eventually connects directly to the northern end of Thorny Bank Wood. There was also recorded activity around

the vicinity of the existing turbine that lies furthest west. No high risk species, such as noctule (Nyctalus noctula)

were recorded during the transect surveys.

4.7 Occasional transect records of common pipistrelle were made close to the southern end of Tower Brook.

4.8 Data collected using the Anabat bat detector support the findings of the bat activity surveys. The bat recordings

collated by the Anabat show that Thorny Bank Wood is regularly used for foraging by a small number of bats. Only

common pipistrelles were recorded by the Anabat when it was positioned on the north east corner of Thorny Bank

Wood, close to the northern end of Tower Brook and the proposed location of Turbine 1.

4.9 In addition, the Anabat detector recorded a high level of activity at the southern end of the site close to Tower

Brook. Common pipistrelle was the most regularly recorded species in this area. However a total of 25 passes of

Nathusius’ pipistrelle (Pipistrellus nathusii) and two noctule passes were recorded on one night when the Anabat

was positioned at location B.



Environment

Survey Results 2010

4.10 No noctule bats were recorded in 2010, which indicates that flights across this site by this species are irregular and

infrequent. The site is therefore unlikely to support a regularly occurring population of this species.

4.11 Common pipistrelle, soprano pipistrelle (Pipistrellus pygmaeus) and Daubenton’s bat (Myotis daubentonii) were

recorded during the transect surveys in 2010. The majority of activity by these species was recorded along the

western edge of the site close to Thorny bank Wood, with occasional records of common and soprano pipistrelle

along the dry stone walls that cross the site in an East-West direction and over the open improved grassland on a

single occasion.

4.12 The Anabat data for 2010 show that Nathusius’ pipistrelle was active in the southern section of the site. Records

for 27/05/10 taken from location B show activity between 22.15 and 4.00 hrs. This translates to approximately one

hour post sunset to sunrise. However Anabat results for 3/06/10 and 14/06/10 show no recordings of bat activity.

Records for 29/09/10 show only one record close to sunset at 19.34. There are only two records for Nathusius’

pipistrelle at location 1 from 22/06/10 taken between 23.00 and 00.00.

4.13 Although small numbers of bats were recorded across the whole site, the autumn data collected in 2010

correspond to those collected in 2009, where activity is concentrated to the west of the site around Thorny Bank

Wood. A Daubenton’s bat was also recorded on the survey conducted on 14/06/10 and soprano pipistrelle was

recorded on 22/06/10. However neither of these two records was verified from recordings analysed through Bat

Sound. Little bat activity was noted on the access track to the north of the site. The majority of trees on the edge

of Thorny Bank Wood have few features to accommodate roosting bats therefore it is suggested that bats are

roosting further to the west of the woodland area.

4.14 The dry stone wall between VP9 and VP10 is used as a flight line by common pipistrelles. The direction and times

of the species recorded indicates that the bats commute east of the site at dawn; to a roost off site. Few bats were

recorded foraging or commuting over open habitats.

Summary of Nathusius’ pipistrelle activity recorded on Anabat

4.15 The numbers of passes at each Anabat location, for each species by date are shown in Table 4.3. All Anabat data

and all available recordings from handheld recording devices used on transects are available on DVD on request.

4.16 The Anabat data show common pipistrelle activity that broadly reflects that recorded during the transects in terms

of temporal and spatial distribution of activity. The data also highlight the significance of the area around Anabat

location B as a flight line which, when considered alongside the transect data presented above, is likely to be along

the dry stone wall in and east-west direction.

4.17 There are also 2 passes of Noctule recorded in September 2009 only. This is discussed in further detail in the

previous sections.

Table 4.3: Summary of Anabat Data

Anabat

Location

Date Species

Common

pipistrelle

Soprano

pipistrelle

Nathusius’

pipistrelle

Noctule

A 05–06/10/2009 62 0 0 0

B 22-23/09/2009 496 0 59 2

B 27-28/05/2010 156 0 79 0



Environment

Anabat

Location

Date Species

Common

pipistrelle

Soprano

pipistrelle

Nathusius’

pipistrelle

Noctule

B 03-04/06/2010 0 0 0 0

B 14-15/06/2010 0 0 0 0

B 28/09/2010 –

01/10/2010

157 0 1 0

C 22-23/06/2010 15 0 3 0

C 15-16/07/2010 0 0 0 0

C 24-25/08/2010 1 0 0 0

4.18 The data collected using the Anabat show that the areas around the dry stone wall between VP9 and VP10 and

the southern reaches of Tower Brook represent a key foraging area and flight line for Nathusius’ pipistrelle. Main

periods of activity were during late May and late September. Only a very small amount of activity was recorded at

the southern end of Tower Brook in June from Anabat location C.

4.19 A summary of the temporal spread of Nathusius’ pipistrelle activity is provided in Graphs 4.1 – 4.4, which present

the number of passes recorded during hourly periods after sunset and before sunrise over the course of a given

evening for different survey dates and Anabat locations.

4.20 The low density of bats recorded on transect surveys is a good indicator that the results for Nathusius’ pipistrelle

represent movements of a small number of individuals commuting and foraging between sunset +1 and sunrise -1

with a drop in activity between these times (Graph 4.1)

4.21 The recordings made at Location C over the course of 3 nights in June and August 2010 show only 2 passes of

Nathusius’ pipistrelle in June over the first half of a single night, and only 3 passes over the whole night. This result

strongly indicates that bats recorded here were not commuting on to or off the site along the south eastern section

of Tower Brook. These passes are therefore likely to be attributable to a very small number of foraging bats, or a

single foraging bat that had reached the limit of its feeding range at this site.

4.22 Graphs 4.3 and 4.4 show a comparison of the seasonal spread of Nathusius’ pipistrelle activity on the site, as

recorded at Anabat locations B and C. The species presence on site is consistent between years, which indicate

that this is a regularly occurring population. What is also consistent is the seasonality of activity, with peak activity

in late September and late May.

4.23 The presence of this species primarily at Anabat location B in both 2009 and 2010 indicates that the dry stone wall

and possibly the southern end of Tower Brook represent regularly used seasonal flight lines and foraging resources

for Nathusius’ pipistrelle. The Anabat results show Nathusius’ pipistrelle behaviour being comparable with common

pipistrelle behaviour on site, although there were more records of common pipistrelle. The data also suggest that

the south of Tower Brook around VP1 and Anabat location B is the extent of the foraging range as records and

abundance decrease at this point, a point which is further confirmed by the presence of Nathusius’ pipistrelle during

the first part of the night in June at Anabat location C. Observations made during the transect surveys of the use of



Environment

the site by common pipistrelle indicate that the key flight line is likely to be the dry stone wall that crosses the

southern end of Tower Brook in an east-west direction.

4.24 Activity for Nathusius’ pipistrelle in May 2010 clearly shows the species foraging up to 3 hours after sunset

followed by a “quiet” period across the middle of the night period, followed by activity peaking again 3 hours before

sunrise. This suggests that the bat has a night roost close by, possibly within Thorny Bank wood. It is likely that

this is a favoured area due to the mixture of habitats present i.e. mature scrub and water.

4.25 The graphs show that there is a low abundance of Nathusius’ pipistrelle activity and in one hour during May 2010

only a maximum of 29 bat passes were recorded (3-2 hours before sunrise). The data suggest that this activity is

attributable to a small number of bats numbering no more than 5 individuals. The decreasing number of passes in

September 2010 can be attributed to reduced autumnal use of the site that might be expected in typical autumnal

conditions on an exposed site such as this one (colder night time temperatures result in a decrease in prey

availability).



Environment

Graph 4.1: All passes of Nathusius’ pipistrelle recorded at Location B.

Graph 4.2: All passes of Nathusius’ pipistrelle recorded at Location C.



Environment

Graph 4.3: Nathusius’ pipistrelle passes in Autumn 2009-10.

Graph 4.4: Nathusius’ pipistrelle passes in late spring-early summer, 2010.



Environment



Environment

Summary of Previous Impact Assessments

5.1 The likely impacts of the proposed development on bats were presented in the ES, based on the results of the

2009 surveys. These were further developed in the addendum report submitted in October 2010, based on the

results of the 2010 surveys. However the presentation and interpretation of the survey data given in those reports

led to a degree of uncertainty over the impact assessments. There were also some inconsistencies and reporting

errors.

5.2 Consequently the consultees were unable to determine whether the development would meet the third criterion

under the Conservation (Natural Habitats, &c) Regulations, Regulation 44 that:

“The actions authorised will not be detrimental to the maintenance of the population of the species concerned at a

favourable conservation status in their natural range.”

5.3 It was not possible to determine with a reasonable degree of confidence the potential impacts of the proposal on

Nathusius’ pipistrelle because the results and analysis of the data did not enable the use of the site by this species

to be determined. This led to the proposal of mitigation that incorporated a high degree of caution in terms of wind

farm design but that did not necessarily address the impacts satisfactorily. Furthermore questions were raised

about the proximity of Turbine 1 to the northern end of Tower Brook in light of the uncertainty expressed regarding

the use of this habitat feature as a flight line and foraging resource for bats.

5.4 The detailed impact assessments and the methodology used to derive them are found in the ES and the addendum

bat report submitted in October 2010 and reference should be made to these documents for such information.

Table 6.14 of the ES identified the greatest potential impacts to be associated with operation of the turbines and

the potential for bats to be killed by rotating turbine blades, either through direct collisions or barotraumas, and

through the interference of bat echolocations or the creation of sonic lures by ultrasound emitted from the turbines.

These impacts were regarded as much greater in overall significance for high risk species (Nathusius’ pipistrelle

and noctule). For lower risk species these impacts were determined as no greater than slight adverse. The

inclusion of mitigation was not sufficient at this stage to lower the impact significance scores for high risk species

because there was insufficient survey data to make this judgement with any confidence.

5.5 Revisions to these scores were made in 2010 following the surveys carried out across a full season of bat activity.

The impacts on low risk species (common and soprano pipistrelle, Myotis spp.) were not changed, meaning that

there was no significant risk to the maintenance of these species populations on the site at a favourable

conservation status.

5.6 However greater consideration was given to the key impacts of the proposal on Nathusius’ pipistrelle and noctule.

Part of October’s addendum report is reproduced below (in italics) to provide a summary of the revised impact

assessments and to provide some context to the further revisions made in this report. Paragraph numbers are

reproduced from the addendum report for clarity:

Para 6.5: The criteria for a species being of high/national importance are for a regularly occurring significant

population/number of any nationally important species i.e. listed on the 1981 Wildlife and Countryside Act (as

amended) and any regularly occurring population of a nationally important species that is threatened or rare in the

county or region. These criteria were applied in the ES to noctule and Nathusius’ pipistrelle.

Para 6.6: In 2009, based on the recorded occurrence of noctule and Nathusius’ pipistrelle, it was determined that

the potential impact that may arise during the operational phase of the windfarm, from bat collisions leading to

injury or fatalities, was large adverse. This was based on the Nature Conservation Value of these species being

high/national importance and the magnitude of potential impact being cautiously assessed, based on limited

survey data, as intermediate negative.

Para 6.7: The data collected during 2009 and 2010 suggest that the noctule records for the site are of sufficiently

small numbers that they do not represent a regularly occurring or significant national, regional or local population

and therefore this species can be regarded as being of Medium Nature Conservation Value at most. Nathusius’

pipistrelle occurs regularly, is a nationally important species and is rare in Lancashire but only low numbers were

5 Discussion of Key

Environmental Impacts



Environment

recorded using the survey area. According to the evaluation criteria outlined in the ES, the population of Nathusius’

pipistrelle recorded at the site is of High Nature Conservation Value.

Para 6.8: For both noctule and Nathusius’ pipistrelle, the chance of mortality caused by collisions with turbine

blades or by barotraumas is likely to be relatively low. In the case of noctule this is because the apparently very

small numbers flying across the site would put few individuals of this species at risk. In the case of Nathusius’

pipistrelle the distribution of flight activity, based on the survey data presented herein, would put few individuals of

this species in contact with the turbines, and the overall numbers of this species using the site appear to be low.

However it is still possible that collisions might occur to the extent that the distribution or status of these species

might be affected at the local level, or might affect the distribution of the species but not affect their population

status at a regional level. The magnitude of potential impact is therefore minor - intermediate negative for both

species. The impact significance for each species is therefore;

• slight – moderate adverse for noctule.

• slight – large adverse for Nathusius’ pipistrelle.

Para 6.9: the impact significance scores for these species incorporate a degree of uncertainty that acknowledges

that bat activity across the site might not be consistent year in year out. However it is anticipated based on the

data presented in this report and the level of “caution” built in to the wind farm design that for the majority of the

time the impacts are likely to be at the lower end of the ranges shown above.

5.7 The mitigation proposed in the October addendum report included the following options (reproduced in italics):

Option 1

Para 6.13; Carry out a programme of monitoring involving further surveys, possibly during construction and the

early stages of wind farm operation. The details of such a programme would be discussed and agreed with

Natural England. The results of the monitoring would form the basis for a mitigation strategy, also to be agreed

with Natural England.

Option 2

Para 6.14: The current buffer between the dry stone wall and the turbine base, in the area between VP9 and VP10

is 72m. The actual distance between the wall and the turbine base is set at 78m. However if there is room to do so

in the wind farm design, consideration could be given to increasing this stand off further through careful micrositing

of turbine 3. This would need to be evaluated against the other constraints to wind farm design.

Option 3

Para 6.15: Given the apparent importance of the dry stone wall that crosses Tower Brook at Anabat location B as

a flight line for Nathusius’ pipistrelle, consideration could be given to diverting this wall away from Turbine 3.

Subject to landowner agreement and any other considerations (such as landscape and archaeological impacts),

the line of the existing wall could be diverted from the eastern bank of Tower Brook so that it follows a line south-

eastwards (instead of north-eastwards) along the northern edge of the disused quarry before diverting north-

eastwards towards the eastern boundary of the survey area (which is also defined by a dry stone wall). This would

have a similar effect to increasing the buffer around this section of dry stone wall to between 200 m and 300m,

which is comfortably within the recommended buffer defined in Rodriguez et al. (Eutobats, 2008). It would also

maintain the existing level of habitat connectivity across the site.

Key concerns to be addressed

5.8 Turbine 1 sits just over 30 m west of the northern end of Tower Brook and, given that this landscape feature was

identified in the ES as of potentially high value for foraging and commuting bats and the ES identified this turbine

as potentially high risk, there was insufficient consideration of the impact of this turbine in 2010’s addendum report.

The generic buffer of 30 m around all watercourses was identified as potentially inadequate to ensure the

protection of bats using this habitat feature at this location.



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5.9 The guidance in Natural England TIN051 sets out a formula for determining adequate buffers around features that

protrude from the ground, such as hedgerows, walls and trees, taking into consideration the dimensions of the

turbines in question. This is to ensure that no part of the turbine blades sweep the airspace within 50m of the

habitat feature. The guidance does not state how such buffers should be determined for ‘negative relief’ features

(i.e. those that cut in to the ground), such as deep cut valleys.

5.10 A need was therefore identified to address this concern through revisiting the buffer around watercourses and

incorporating this through micro-siting of Turbine 1, pending a more detailed analysis of the survey results.

5.11 The creation of a larger buffer around the dry stone wall at Turbine 3, in line with Eurobats Guidance (Rodriguez et

al., 2008), through the diversion of the dry stone wall, raised the question of whether or not there was a significant

amount of Nathusius’ pipistrelle activity in this area that:

• Could be quantified by the existing survey data.

• Would warrant cause for concern.

• Could not be mitigated effectively through the use of buffers incorporated into the wind farm design in line with

guidance in Natural England Technical Information Note TIN051.

5.12 The effectiveness of moving the dry stone wall was also called into question on the basis that there was no way of

knowing whether or not bats would alter their behaviour to follow the diverted wall line.

Revisions to Wind Farm Design and Mitigation

5.13 Detailed presentation and discussion of all survey data has been provided in previous sections of this report. The

data collected represent the presence, abundance and activity of bat species on site throughout the active period

April - September. The key summary points are:

• The site is cold, exposed and over most of its area, characterised by improved grassland that is intensively

grazed and puddled by livestock. With the exception of Thorny Bank Wood, Tower Brook and the dry stone

walls that cross the site there are few habitats of value for foraging bats.

• Overall numbers of bats, based on first-hand observations on transect surveys and interpretation of the Anabat

data, are very low and generally fewer than 5 individuals at any one time.

• The vast majority of bat activity is restricted to the high value habitat features, particularly Thorny Bank Wood

on the western side of the site and the dry stone wall to the south of Turbines 2 and 3.

• Activity by low risk species, especially common pipistrelle, is consistent throughout the activity season and

between years.

• Recorded activity of noctule was not consistent between years and therefore the use of the site by this species

is very unlikely to be by a regularly occurring significant population. The risk to this species is therefore

extremely low.

• Recorded activity of Nathusius’ pipistrelle and interpretation of the survey data in light of what is known about

the biology of this species, the rationale for the survey methods, and how bats are using the site in general

strongly indicates that there is a very small population of this species whose use of the site is restricted

primarily to late spring and Autumn and to the area of dry stone wall and the southern end of Tower Brook close

to Anabat Location B. This species’ activity was strongly indicative of foraging behaviour, which would be

mostly restricted to linear habitat features.

• There is no reason to believe that, despite the obvious potential of Tower Brook as a landscape habitat feature

for bats, its northern reaches (close to Turbine 1) are used regularly by large numbers of any species of bat.

• The survey data indicate that the open habitats of the site are not regularly or frequently crossed by migrating

or commuting bats.



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• The main risks to bats would therefore be associated with the proximity of the proposed turbine locations to

linear habitat features, particularly at Turbines 1 and 3.

5.14 Table 5.1 shows the dimensions of each proposed turbine, the minimum buffers required around habitat features

according to the formula set out in Natural England TIN051 and the buffers achieved through wind farm design.

Micro-siting of Turbine 1 was implemented such that this turbine is now 60 m from Tower Brook, more than 100 m

from Thorny Bank Wood and more than 72 m from the nearest wall or hedgerow. This has been achieved by

moving the turbine approximately 32 m to the south to take advantage of a bend in Tower Brook that takes the line

of the watercourse eastwards. This is shown on the constraints plan included as Appendix F. Drawings that set

out the turbine buffers, for each turbine size, from walls/hedgerows and Tower Brook are given in Appendix G for

clarity.

Table 5.1: Revised Habitat buffers* for bats required to achieve compliance with Natural England

guidance.

Parameter Turbine 1 Turbine 2 Turbine 3

Hub height 69 m 69 m 59 m

Blade length 41 m 41 m 41 m

Feature Type: wall/hedgerow

Feature height1 2.5 m

Minimum safe buffer 62.1 m 62.1 m 71.3 m

Design buffer 72 m

Design buffer acceptable? Yes Yes Yes

Turbine position acceptable? Yes Yes Yes (78m from wall)

Feature Type: Woodland

Feature height1 20 m


Design buffer 100 m

Design buffer acceptable? Yes Yes Yes

Turbine position acceptable Yes Yes Yes

Feature Type: Tower Brook

Feature height2 0 m


Design buffer 60 m

Design buffer acceptable? Yes Yes No

Turbine position acceptable Yes (60 m from Tower Brook)

Yes(aApprox 300 m from Tower Brook)

Yes (approx 250 m from Tower Brook)

* Buffers are the distance between the habitat feature and the base of the turbine tower 1Cautious estimate

2 Assumes the top of the gulley is at ground level, i.e. 0 m elevation



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5.15 Based on all of the results and analyses presented in this report, plus the revised wind farm design, the mortality of

all species of bat recorded due to operation of the proposed turbines will be extremely low:

• The impact assessment for mortality of Noctule is now assessed as Neutral due to the very infrequent

presence of this species.

• The impact assessment for mortality of Nathusius’ pipistrelle is predicted to be no greater than slight

adverse due to the very limited presence of this species in terms of overall numbers, seasonal presence and

the restricted spatial presence of the species (i.e. around linear habitat features only).

• The impact assessments for all other species are unchanged.

5.16 Based on the information presented, the wind farm design has been revised slightly and the use of Natural

England guidance buffers is deemed adequate to ensure that criterion 3 of the Conservation (Natural Habitats,

&c) Regulations, Regulation 44 can be met such that “the maintenance of the population of the species

concerned at a favourable conservation status in their natural range” will not be threatened by the

proposal. It is therefore no longer considered necessary to incorporate additional caution in the wind farm design

and that the use of buffers specified in Eurobats guidelines (Rodriguez et al., 2008) has been dropped from the

design.



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Baerwald, E.F., D’Amours, G. H., Klug, B.J. and Barclay, R.M.R. (2008). Barotrauma is a significant cause of bat

fatalities at wind turbines. Current Biology Vol 18, No. 16.

Bat Conservation Trust (2007). Bat Surveys – Good Practice Guidelines. BCT

Mitchell-Jones, T. And Carlin, C. (2009). Technical Information Note TIN051: Bats and onshore wind turbines. Natural

England

Rodriguez, L., Bach, L., Dubourg – Savage, MJ., Goodwin, J. and Harbusch, C. (2008). Guidelines for consideration of

bats in wind farm projects. Eurobats Publication Series No. 3.

6 References



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Figures



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Appendix A: Consultee comments

and written responses



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Appendix B: Survey Forms 2009



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Appendix C: Survey Forms 2010



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Appendix D: Bat Activity Figures 2009



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Appendix E: Bat Activity Figures 2010



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Appendix F: Revised Constraints Plan and Turbine Layout



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Appendix G: Turbine buffer drawings

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