bat hibernation survey report - borough of … 0397 bat...bat hibernation survey report sk...

LLOYD BORE LTD OF FICE 4 , MA UDL A ND S

MA UDE STREET , KEN DAL CUMBR IA, LA 9 4 Q D

Te l : 01 53 9 7 38 411 Fa x: 01 227 46 4 3 41

r ic h@ l loy d bor e.co . u k www. l loy d bor e.co . u k

B A T H I B E R N A T I O N S U R V E Y

R E P O R T

SK ENVIRONMENTAL SOLUTIONS LTD

FINSLEY GATE MILL BURNLEY, BB11 2JA

REF NO. C468-RP03

DOCU MENT CRE ATED: 19 / 01/2 016

AUTHOR : R I CH FL IGHT B SC (HON S) MCIEE M

1

C468-RP03 | BAT HIBERNATION REPORT

FINSLEY GATE, BURNLEY STATUS: PLANNING

18 JANUARY 2016

CONTENTS

EXECUTIVE SUMMARY ................................................................................................................................... 2

INTRODUCTION ................................................................................................................................................ 3

Instruction ............................................................................................................................................. 3

Description of proposed development ................................................................................................. 3

Scope of works..................................................................................................................................... 3

Survey objectives ................................................................................................................................. 3

2. SITE LOCATION ....................................................................................................................................... 4

Site Description .................................................................................................................................... 4

3. METHOD .................................................................................................................................................... 6

Internal Inspections of the building ...................................................................................................... 6

Static Detector Survey ......................................................................................................................... 6

Survey details ....................................................................................................................................... 7

Legislation and planning policy ............................................................................................................ 7

Assessment and evaluation ................................................................................................................. 8

Zone of influence (ZoI) ......................................................................................................................... 8

Survey limitations ................................................................................................................................. 9

4. SURVEY RESULTS ................................................................................................................................. 10

Desk study ......................................................................................................................................... 10

Internal Hibernation inspections......................................................................................................... 11

Static Detector Survey ....................................................................................................................... 11

Environmental Conditions .................................................................................................................. 12

5. EVALUATION AND RECOMMENDATIONS .......................................................................................... 15

Evaluation .......................................................................................................................................... 15

6. REFERENCES ......................................................................................................................................... 17

APPENDIX 1 PHOTOGRAPHS ................................................................................................................. 18

APPENDIX 2 SURVEY PLAN (NOT TO SCALE) ...................................................................................... 22

APPENDIX 3 DEMOLITION PLAN ............................................................................................................ 23

2



18 JANUARY 2016

EXECUTIVE SUMMARY

S.1 The current proposals include the demolition of the majority of Finsley Gate Mill and chimney, on health and safety grounds.

S.2 Previous bat surveys have been conducted at the survey site by FPCR in 2010, 2011 and 2013, and by Lloyd Bore Ltd in 2015. A very low number of common pipistrelle bats were recorded roosting in the administration section of the building. None of the roosting sites were in locations that would be directly affected by the proposed demolition.

S.3 Recommendations for appropriate mitigation were made in the previous bat survey report (Lloyd Bore, 2015, C468-RP01) and an ecological method statement for the demolition of the mill was also drawn up (Lloyd Bore, 2015, C468-RP02).

S.4 The mill features areas that have some potential for hibernating bats, most notably the ground and lower ground floors, which are dark, enclosed and damp.

S.5 A hibernation study was therefore undertaken to investigate the potential presence of hibernating bats in the building. This included three site visits and the use of static detectors, which record bat activity for extended periods of time, and data loggers to monitor the environmental conditions within the building.

S.6 No bats were found during the site inspections, and no bats were recorded by the static detectors.

S.7 The environmental conditions in the building were found to fluctuate too greatly to make the site suitable for hibernating bats.

S.8 It is therefore concluded that bats do not hibernate in the building and therefore, no further mitigation is required.

S.9 On the basis of this survey, it will not be necessary to obtain a European Protected Species Mitigation (EPSM) before development commences.

S.10 Recommendations and precautions laid out in the previous report (Lloyd Bore, 2015, C468-RP01) and method statement (Lloyd Bore, 2015, C468-RP02) should be adhered to.

Author Rich Flight BSc (Hons) MCIEEM

Checked By Lucy Gibson MSc MCIEEM

3



18 JANUARY 2016

INTRODUCTION

INSTRUCTION

1.1. Lloyd Bore Ltd was instructed by Michael Kurs of SK Environmental Solutions to undertake a bat hibernation survey at Finsley Gate Mill, Burnley, BB11 2JA (approximate centre of site SD 841 320).

DESCRIPTION OF PROPOSED DEVELOPMENT

1.2. The current proposals include the demolition of the majority of the existing mill building, on health and safety grounds (see Appendix 3).

SCOPE OF WORKS

1.3. The instructed works included three inspection surveys of the building, as well as the deployment of two static bat detectors within the building. Two licensed bat surveyors were present at the first inspection, and one licensed bat surveyor and one member of demolition staff were present for the second and third inspections.

1.4. Previous summer bat survey work has been carried out (Lloyd Bore, 2015), and two bat roosting locations (see appendix 2) were identified on areas of the building which will not be affected by the proposed demolition (see appendix 3).

SURVEY OBJECTIVES

1.5. The objectives of the survey and report are to:-

• Identify whether bats are hibernating within the building, most notably, the ground and lower ground floors, which have been sealed up, making them permanently dark.

• Determine whether a European Protected Species Mitigation (EPSM) licence is likely to be required to facilitate development; and

• Make recommendations, if required, regarding appropriate avoidance measures, mitigation or, if necessary, compensation measures.

4



18 JANUARY 2016

2. SITE LOCATION

Fig. 1: Location plan of survey site (arrowed).

SITE DESCRIPTION

2.1. The existing building is a large decommissioned mill, located south of the A682 Centenary Way. It lies to the south of Burnley town centre and is adjacent to the Leeds to Liverpool canal. The building has three storeys and a basement. It is composed of a large factory floor section, a wing of smaller administration rooms and a shop floor on the north-western end of the building. The site also includes a large brick chimney located at the far north-west end of the survey site. The building has remained unused and derelict since 2007 and is in a generally poor structural condition.

2.2. Externally, the building is constructed from well-pointed sandstone. As it has lain disused for a number of years, windows have been broken and the roof has now partially collapsed. Ground floor windows have been sealed with concrete blocks with gap vents left at the top of the filled windows. Ruderal plant species, such as Buddleia, can be seen growing out of the building itself.

5



18 JANUARY 2016

2.3. Due to the blocked windows, the ground floor level is permanently dark. This floor features extensive areas of standing water, where rain water has leaked in. Similarly, in the lower ground floor, the floor is thinly flooded. The 1st floor of the main mill is open and light due to the open windows. There is ivy growing into the building. The ceiling is wooden panelled, which creates a small void between the joists. The 2nd floor is light, open and draughty, with broken windows and large holes in the ceiling with some vegetation growing from both the windows and ceiling.

2.4. In the north-west wing, the windows are blocked and the shop floor is damp throughout. The wall paint is peeling and there is debris on the floor. On the ground floor/basement there are no exposed beams. However, on the top floor, the roof is vaulted with exposed beams; there is bitumen felt on the southern pitch and no lining on the northern pitch. Small gaps are visible around slates and window boarding.

2.5. There are commercial buildings in relatively close proximity to the north and west of the site, which continue to the centre of the town. The surrounding areas to the west, east and south east are largely composed of intensive residential housing estates, with the closest being to the south-east approximately 100m away.

2.6. The canal is the only major waterway within close proximity to the site, which runs parallel along the length of the south side of the building, and turns 90° before continuing to run along the western side.

2.7. A discontinuous line of trees borders the length of the canal, part of which has been recently felled in the areas close to the building. There are also two small patches of woodland located to the south and west of the site, which are approximately 150m and 200m away respectively. Approximately 250m to the south lies a large area of open fields, which connects Finsley Gate Mill to the surrounding rural area. Furthermore, Healey Heights Recreation Ground woodland approximately 500m to the south-west features an area of trees measuring roughly 4ha. Within Towneley Park approximately 1200m to the south-west lies Causeway End Wood and Thanet Lee Wood, which measures approximately 26ha in area.

6



18 JANUARY 2016

3. METHOD

INTERNAL INSPECTIONS OF THE BUILDING

3.1. Detailed internal inspections were carried out on three occasions, 10th and 23rd December 2015, and 13th January 2016. The inspections were undertaken during daylight and focussed on the ground and lower ground floors of the main mill building, which have been partially sealed up and therefore provide a permanently dark and humid environment. An examination of the interior was undertaken from ground level, as far as possible, to look for evidence of hibernating bats, that may include:-

• Bats;

• Bat droppings; and

• Signs of feeding

3.2. Particular attention was given to areas where bats might be tucked out of immediate sight, such as in expansion cracks and gaps between ceiling boards.

STATIC DETECTOR SURVEY

3.3. Two static detectors were deployed within the ground and lower ground floors of the building between the period of 10th December 2015 and 13th January 2016. This comprised one Anabat Express, positioned on the ground floor and one Anabat SD1 on the lower ground floor.

3.4. Both detectors recorded 24 hours a day, in order to potentially detect bats moving into the building at night time as well as bats that may move around in the building at any time of the day. The Anabat Express was powered by lithium AA batteries and the Anabat SD1 unit was powered by an external 12V battery.

3.5. Data recorded by the static detectors was analysed using AnalookW v4.1 sound analysis software. Sound files were analysed using a filter to extract bat calls and were manually checked by an experienced bat ecologist for accuracy.

3.6. Between the 23rd December and the 13th January, temperature and relative humidity data loggers (Omega OM-EL-USB-2) were also deployed; one on the lower ground floor and one outside the eastern elevation of building. This provided a log of the environmental conditions within the building as well as a comparison with the external conditions. The Anabat Express also logged temperature during its operation.

7



18 JANUARY 2016

SURVEY DETAILS

3.7.

Date of survey

Survey type

Start time

Finish time

Surveyors Weather

10.12.2015 Daytime

Inspection 09.00 10.30

Lucy Gibson (licensed batworker 2015-

12291-CLS-CLS), Rich Flight (licensed

batworker 2015-15641-CLS-CLS)

Dry, overcast, cool, light breeze, ~7°C

23.12.2015 Daytime


Rich Flight (licensed batworker 2015-15641-CLS-CLS)

Dry, overcast, cool, light breeze, ~8°C

13.01.2016 Daytime


Rich Flight (licensed batworker 2015-15641-CLS-CLS)

Dry, >90% cloud cover, cold, light breeze, ~2.5°C

LEGISLATION AND PLANNING POLICY

3.8. The Conservation of Habitats and Species Regulations 2010 (as amended) and the Wildlife and Countryside Act 1981 (as amended) afford legal protection to bats.

3.9. The specific legal protection afforded to bats can be found within the Sections and Schedules of the relevant legislation and relevant case law.

3.10. In general, any person and/or activity that:-

• Damages or destroys a breeding or resting place of bats. (This is sometimes referred to as the strict liability or absolute offence);

• Deliberately captures, injures or kills a bat/s;

• Deliberately disturbs bats, and in particular disturbance likely to impair animals ability to survive, breed or nurture young, their ability to hibernate and migrate and disturbance likely to have a significant effect on local distribution and abundance;

• Intentionally or recklessly disturbs a bat/s while occupying a structure or place used for shelter and/or protection (Wildlife and Countryside Act 1981 (as amended)); and

• Intentionally or recklessly obstructs access to any structure or place that a bat/s use for shelter or protection (Wildlife and Countryside Act 1981 (as amended)).

8



18 JANUARY 2016

…may be guilty of an offence.

3.11. The legislation applies to bat roosts even when they are not occupied.

3.12. Maximum penalties are punishable with fines up to £5,000 per offence and up to 6 months imprisonment. Actions affecting multiple animals can be construed as separate offences and therefore penalties can be applied per animal impacted.

3.13. Under certain circumstances licences can be granted by the Statutory Nature Conservation Organisation (Natural England in England) to permit actions that would otherwise be unlawful.

3.14. There are some very specific defences associated with the Conservation of Habitats and Species Regulations 2010 (as amended), however these are unlikely to apply to construction related projects. The Sections of the Regulations provide further details of these defences.

3.15. The Wildlife and Countryside Act (1981) includes defence for those aspects of the legislation that apply to bats. These defences are unlikely to apply to construction related projects and do not apply to those acts included in the Conservation of Habitats and Species Regulations 2010 (as amended). The Schedules of the Act provide further details of defences.

3.16. Local authorities have obligations under sections 40 and 41 of the Natural Environment and Rural Communities Act (NERC) 2006 to have regard to the purpose of conserving biodiversity in carrying out their duties. Seven species of bat species are listed on Section 41 the NERC Act.

ASSESSMENT AND EVALUATION

3.17. The Bat Conservation Trust's Survey Guidelines (2012) and the Bat Workers Manual (JNCC, 2004) have been used to

• Assess the building's potential to support bats;

• Assess the likely value of the habitats for foraging bats; and

• Inform the scope of the survey works required to assess whether bats are using the building to roost.

3.18. Natural England Standing Advice (undated), which is a material consideration in planning, also provides details on survey methodology and how the implementation of mitigation measures, such as using recognised techniques at the appropriate time of year, can reduce the scope of survey work required.

3.19. The Guidelines for Ecological Impact Assessment (IEEM, 2006) were used as guidance to determine the importance (or value) of the site, and the habitats immediately surrounding the site, for bats.

ZONE OF INFLUENCE (ZOI)

3.20. The potential impact of a development is not always limited to the boundaries of the survey site. The development may also have the potential to impact on ecologically valuable sites, habitats or species beyond the site boundaries. The area over which a development may impact ecologically valuable receptors is known as the Zone of Influence (ZoI).

3.21. The ZoI is determined by the source/type of impact, a potential pathway for that impact and the location and sensitivity of the ecologically valuable receptor beyond the boundary.

3.22. Potential sources of impact associated with the proposed development include potential loss of a roosting site (if roosting bats are present) and light spillage onto surrounding bat foraging and commuting habitats.

9



18 JANUARY 2016

3.23. The effects of light spillage can be mitigated for to minimise its potential impact. Therefore, the zone of influence is confined to the red line boundary of the site and to habitats upon which light spillage may fall.

SURVEY LIMITATIONS

3.24. Access could not be gained to all of the internal areas, as the first and second floors were generally unsafe to fully inspect. However, these areas were not sealed and therefore illuminated during the day and were considered unlikely to provide potential for hibernating bats.

3.25. The chimney could not be inspected for health and safety reasons.

3.26. Due to the amount of water and debris on the floors of the building, it is possible that bat droppings, if present, would have been masked by the water/debris.

3.27. Due to limited battery life, the detectors did not record for the entire survey period.

3.28. Data loggers were only available for the period between the second and third visit. However, the Anabat Express logged the temperature during its operation.

3.29. During the majority of the survey period, weather conditions were unseasonably warm, with the highest average temperature on record for December. It was also the wettest month on record. This variation from the norm may have unpredictably affected bat behaviour.

10



18 JANUARY 2016

4. SURVEY RESULTS

DESK STUDY

4.1. Eight species of bats have been recorded regularly in Lancashire; whiskered (Myotis mystacinus), Brandt’s (Myotis brandtii), Natterer’s (Myotis nattererii), Daubenton’s (Myotis daubentonii), noctule (Nyctalus noctula) and brown long-eared bats (Plecotus auritus) as well as two species of pipistrelles; the common (Pipistrellus pipistrellus) and soprano pipistrelle (Pipistrellus pygmaeus).

4.2. The status of the above species in the local/regional area is as follows:

− Whiskered bat – widespread.

− Brandt’s bat - Present

− Natterer’s bat – widespread but thinly distributed.

− Noctule – widespread.

− Brown long-eared bat – widespread.

− Common and soprano pipistrelle – common and widespread.

− Daubenton’s bat – widespread near water.

4.3. A further three bat species have been identified in Lancashire, however, in very low numbers or with few records including: Leisler’s bat (Nyctalus leisleri) with only one record in Lancashire, lesser horseshoe bat (Rhinolophus hipposideros) and nathusius’ pipistrelle (Pipistrellus nathusii).

4.4. A data search was undertaken for the previous survey report (Lloyd Bore 2015) by the Lancashire Environment Record Network (LERN) to generate records of bats held within their database from locations within a 2km radius of the survey site.

4.5. Records within 2km of the site from between 1998-2013 show:

− 3x Daubenton’s bat (Myotis daubentonii), including a maternity roost and a winter hibernation site.

− 1 x Natterer’s bat (Myotis nattererii).

− 2 x Noctule bat (Nyctalus noctula), including a tree roost.

− 2 x Brown long-eared bat (Plecotus auritus), including a hibernation site.

− 9 x Common pipistrelle (Pipistrellus pipistrellus), including five roosts and a hibernation site.

− 1 x Soprano pipistrelle (Pipistrellus pygmaeus).

− In addition to 25 records of unidentified bat species.

4.6. The majority of these records, including all of the mentioned roosts and hibernation sites, were located in Towneley park, located south-east of the site, which includes substantial areas of woodland, notably Thanet Lee Wood and Causeway End Wood.

11



18 JANUARY 2016

INTERNAL HIBERNATION INSPECTIONS

4.7. The ground and lower ground floor windows have been sealed with concrete blocks and wooden boards. Small gaps have been left at the top of the concrete to vent the internal air. These gaps may provide small crevices within which bats may roost. In addition, they also provide potential access into the lower floors of the building, which are permanently dark and therefore may be suitable for hibernating bats.

4.8. On close inspection, the building has few internal locations that would provide hibernating potential for crevice-dwelling bats, such as pipistrelle species. The walls are relatively featureless and lack any significant crevices. The ceilings are concrete with wooden panelling, which has fallen away in many locations. This may provide some potential crevices within which bats might be able to roost. However, during the survey, the vast majority of these wooden panels were very wet from significant water ingress.

4.9. There is some low potential for open-hibernating bats, such as Myotis spp bats, which may hibernate against the concrete beams, or within the inset window alcoves, which provide some contouring within which bats could position themselves.

4.10. The ground and lower ground floors feature considerable amounts of standing water. The building lacks a roof and therefore rain-water percolates through the entire building and collects on these two floors. Although hibernating bats require a humid environment to avoid desiccation, large areas of the ceiling and some of the walls were wet and often dripping. This is likely to be too wet for hibernating bats to roost against and therefore would limit the number of locations where bats could utilise.

4.11. The upper two floors are in poor repair, in particular the top floor, which features the collapsed roof. On both floors, the windows have been broken, allowing light and airflow into the building. During the day these floors are likely to be too light for roosting bats. However, more importantly for hibernating bats, the airflow will mean that the temperature and humidity on these floors will fluctuate regularly.

4.12. During the course of the survey, at least two floors of the building (not within the scope of the hibernation survey) collapsed due to the advanced state of disrepair.

4.13. During the surveys, all available crevices and potential roosting locations within the ground and lower ground floor were inspected as far as possible. No bats or bat droppings, feeding remains, or other evidence of bats was found during the inspections.

STATIC DETECTOR SURVEY

4.14. The static bat detectors recorded ultrasound from within the mill, 24 hours a day. The amount of ultrasound detected had an impact on the lifespan of the batteries; the more the detectors were triggered, the less time the batteries lasted. The detectors were therefore active for the following periods;

Anabat Express (ground floor): 10/12/15 – 20/12/15 (10 days)

23/12/15 – 31/12/15 (8 days)

Anabat SD1 (lower ground floor): 10/12/15 – 21/12/15 (11 days)

23/12/15 - 04/01/16 (12 days)

4.15. During the course of the static detector survey no bats were recorded. The detectors were regularly triggered but all recordings were of background noise, most notably the dripping of water, which generates sound at a very high frequency that is picked up by the ultrasonic microphones.

12



18 JANUARY 2016

ENVIRONMENTAL CONDITIONS

4.16. Data loggers were deployed between the 23rd December and the 13th January. These devices recorded the temperature and humidity on site at half hourly intervals.

4.17. One data logger was placed within the lower ground floor, on a small internal ledge, while the other was deployed outside the building, in the eastern courtyard. This was to provide a comparative dataset that would enable a gauge of the suitability of the site as a hibernation location.

4.18. The Anabat Express, which was placed on the ground floor, also logged temperature throughout its operation.

4.19. The following graphs (Figures 2-4) provide the results from the data collection periods;

Fig. 2: Graph of temperature data from Anabat Express on ground floor between 10/12/15 and 31/12/15 (missing data due to lack of battery power)

0

2

4

6

8

10

12

14

10/1

2/20

15 0

9:16

10/1

2/20

15 2

0:51

11/1

2/20

15 0

8:34

11/1

2/20

15 2

0:11

12/1

2/20

15 0

7:53

12/1

2/20

15 1

9:31

13/1

2/20

15 0

7:13

13/1

2/20

15 1

8:51

14/1

2/20

15 0

6:33

14/1

2/20

15 1

8:11

15/1

2/20

15 0

5:53

15/1

2/20

15 1

7:31

16/1

2/20

15 0

5:13

16/1

2/20

15 1

6:51

17/1

2/20

15 0

4:33

17/1

2/20

15 1

6:10

18/1

2/20

15 0

3:53

18/1

2/20

15 1

5:30

19/1

2/20

15 0

3:13

19/1

2/20

15 1

4:50

20/1

2/20

15 0

2:32

20/1

2/20

15 1

4:10

21/1

2/20

15 0

1:52

21/1

2/20

15 1

3:35

22/1

2/20

15 0

1:17

22/1

2/20

15 1

2:59

23/1

2/20

15 0

0:42

23/1

2/20

15 1

2:24

24/1

2/20

15 0

0:01

24/1

2/20

15 1

1:43

24/1

2/20

15 2

3:22

25/1

2/20

15 1

1:04

25/1

2/20

15 2

2:42

26/1

2/20

15 1

0:24

26/1

2/20

15 2

2:02

27/1

2/20

15 0

9:44

27/1

2/20

15 2

1:21

28/1

2/20

15 0

9:04

28/1

2/20

15 2

0:41

29/1

2/20

15 0

8:24

29/1

2/20

15 2

0:01

30/1

2/20

15 0

7:43

30/1

2/20

15 1

9:21

31/1

2/20

15 0

7:03

Anabat Express Temperature Data (10/12/15 to 31/12/15)

Tem

pera

ture

(°C)

Date & Time

13



18 JANUARY 2016

Fig. 3: Graph of temperature and relative humidity data from internal data logger on lower ground floor between 23/12/15 and 13/01/16

Fig. 4: Graph of temperature and relative humidity data from external data logger between 23/12/15 and 13/01/16

0

20

40

60

80

100

120

0

2

4

6

8

10

12

1423

/12/

2015

13:

2624

/12/

2015

01:

2624

/12/

2015

13:

2625

/12/

2015

01:

2625

/12/

2015

13:

2626

/12/

2015

01:

2626

/12/

2015

13:

2627

/12/

2015

01:

2627

/12/

2015

13:

2628

/12/

2015

01:

2628

/12/

2015

13:

2629

/12/

2015

01:

2629

/12/

2015

13:

2630

/12/

2015

01:

2630

/12/

2015

13:

2631

/12/

2015

01:

2631

/12/

2015

13:

2601

/01/

2016

01:

2601

/01/

2016

13:

2602

/01/

2016

01:

2602

/01/

2016

13:

2603

/01/

2016

01:

2603

/01/

2016

13:

2604

/01/

2016

01:

2604

/01/

2016

13:

2605

/01/

2016

01:

2605

/01/

2016

13:

2606

/01/

2016

01:

2606

/01/

2016

13:

2607

/01/

2016

01:

2607

/01/

2016

13:

2608

/01/

2016

01:

2608

/01/

2016

13:

2609

/01/

2016

01:

2609

/01/

2016

13:

2610

/01/

2016

01:

2610

/01/

2016

13:

2611

/01/

2016

01:

2611

/01/

2016

13:

2612

/01/

2016

01:

2612

/01/

2016

13:

2613

/01/

2016

01:

2613

/01/

2016

13:

26

Internal Data Logger (23/12/15 to 13/01/16)

Celsius(°C)

DewPoint(°C)Humidity(%rh)

Tem

pera

ture

(°C)

Hum

idity

(%rh

)

Date & Time

0

20

40

60

80

100

120

0

2

4

6

8

10

12

14

23/1

2/20

15 1

3:26

24/1

2/20

15 0

1:56

24/1

2/20

15 1

4:26

25/1

2/20

15 0

2:56

25/1

2/20

15 1

5:26

26/1

2/20

15 0

3:56

26/1

2/20

15 1

6:26

27/1

2/20

15 0

4:56

27/1

2/20

15 1

7:26

28/1

2/20

15 0

5:56

28/1

2/20

15 1

8:26

29/1

2/20

15 0

6:56

29/1

2/20

15 1

9:26

30/1

2/20

15 0

7:56

30/1

2/20

15 2

0:26

31/1

2/20

15 0

8:56

31/1

2/20

15 2

1:26

01/0

1/20

16 0

9:56

01/0

1/20

16 2

2:26

02/0

1/20

16 1

0:56

02/0

1/20

16 2

3:26

03/0

1/20

16 1

1:56

04/0

1/20

16 0

0:26

04/0

1/20

16 1

2:56

05/0

1/20

16 0

1:26

05/0

1/20

16 1

3:56

06/0

1/20

16 0

2:26

06/0

1/20

16 1

4:56

07/0

1/20

16 0

3:26

07/0

1/20

16 1

5:56

08/0

1/20

16 0

4:26

08/0

1/20

16 1

6:56

09/0

1/20

16 0

5:26

09/0

1/20

16 1

7:56

10/0

1/20

16 0

6:26

10/0

1/20

16 1

8:56

11/0

1/20

16 0

7:26

11/0

1/20

16 1

9:56

12/0

1/20

16 0

8:26

12/0

1/20

16 2

0:56

13/0

1/20

16 0

9:26

External Data Logger (23/12/15 to 13/01/16)

Celsius(°C)

DewPoint(°C)Humidity(%rh)

Tem

pera

ture

(°C)

Hum

idity

(%rh

)

Date & Time

14



18 JANUARY 2016

4.20. The graphs show that the internal temperature at Finsley Gate Mill fluctuates in response to the external temperature. The temperatures recorded on the Anabat, which was positioned at ground level in the building, range from 4°C to 13.25°C. There is no record of the external temperatures during this period but it was generally an unseasonably warm and wet period of weather.

4.21. The data logger positioned on the lower ground level recorded temperatures between 4.5°C and 9°C. This logger was not in position during the warmest period of December and therefore did not record temperatures as high as the Anabat. However, when both data logger and Anabat were operating at the same time (between 23/12 and 31/12) the Anabat consistently recorded temperatures of approximately 1.5°C above that of the internal data logger. This reflects the higher temperature achieved on the ground floor as opposed to on the lower ground floor, where the logger was. Otherwise, the temperature readings are very similar.

4.22. The external data logger shows similar fluctuations in general temperature to the internal logger but to a more extreme extent. The external temperature varies from 1.5°C to 12°C. The internal environment of the mill appears to buffer the more extreme variations, as well as the short term variations in conditions caused by wind and rain.

4.23. Relative humidity recorded on the internal data logger ranged from 90.5 to 100%. However, it did not fluctuate greatly and once it reached 100%, it stayed there for the rest of the survey. This reflects the very wet atmosphere in the mill building.

4.24. The external logger provided similar results to the internal device, but again fluctuated on a small scale. Although the external humidity appears to be high for the majority of the survey, most likely due to the very high rainfall, the logger did record a drop in humidity on the 28th December, which does not appear to be reflected in the internal humidity. This again demonstrates the buffering action that the building provides.

15



18 JANUARY 2016

5. EVALUATION AND RECOMMENDATIONS

EVALUATION

5.1. As a result of the hibernation surveys carried out in this study, no bats were observed to be hibernating within the mill, and no bats were recorded flying within the ground or lower ground floor of the mill building.

5.2. During the inspections, no bats or any evidence of bats was found on site. Hibernating bats could be expected to be found in two types of locations; crevice locations and open locations. Bats such as pipistrelle bats tend to hibernate in small crevices, while species such as Myotis spp bats and brown long-eared bats hibernate in more open locations or in small alcoves and hollows in stone-work. Both types of location were inspected as part of the survey and no hibernating bats were found.

5.3. Summer activity survey work established that the area has a general lack of Myotis spp bats. The exception being the presence of Daubenton’s bats, which were observed feeding over the canal. No brown long-eared bats were recorded during summer survey work.

5.4. Pipistrelle bats are known to hibernate in external crevices of buildings. However, the building is generally well-pointed and therefore does not feature an abundance of external crevices suitable for hibernating bats, therefore external crevices were not included as part of the inspection.

5.5. During the inspections it was noted that there were significant amounts of water percolating through the building, providing a very wet environment internally. The majority of ceilings were rotten and were constantly dripping and the walls were mainly wet. These wet conditions do not provide optimal hibernating conditions for bats. Although bats require a high humidity to hibernate to avoid desiccation, in such wet conditions the bats are likely to get wet and chilled, and would therefore need to use up valuable energy to warm themselves back up. There were few locations that presented dry yet humid conditions suitable for hibernation.

5.6. During the period of static bat detection, which covered a total period of 23 days, no bats were recorded flying within the ground or lower ground floors. Although bats enter a period of deep torpor during the hibernation period, they are known to rouse themselves relatively frequently to relocate or even undertake occasional foraging flights outside. If bats were hibernating in the mill then it is very likely that they would have been recorded on the detectors during the survey, particularly due to the mild conditions. The fact that no bat calls were recorded at all suggests that no bats have been flying within the mill during this period and therefore no bats have been hibernating there either.

5.7. This is particularly relevant considering the warm temperatures experienced during December, which may have provided torpid bats with suitable weather conditions within which to undertake short foraging flights.

5.8. The environmental data provides an insight into the reason why no bats were found hibernating within the mill building. On top of the very wet conditions, the temperature within the building appears to fluctuate too greatly. In order to successfully hibernate, bats require an environment which mimics that of a cave, i.e. a constant low temperature and a constant high humidity. Although the humidity of the site remained high (due to the volume of water percolating through the building), the temperature did not maintain a low level. Figures 2-4 show a temperature range of 9.25°C, with internal temperatures reaching as high as 13.25°C. Faced with such fluctuations, hibernating bats will be required to use up energy to compensate for the variation, which may leave them lacking the energy reserves required to survive the winter period; especially if there is a late cold period. In addition to this, bats, which normally have a body temperature of under 10°C when hibernating, cannot lower

16



18 JANUARY 2016

their body temperature below the environmental conditions. Therefore, during the periods when the ambient temperature was above 10°C, it is likely that the bats would not have been able to successfully enter topor at all.

5.9. There is no evidence to suggest that the building supports any hibernating bats. It is likely that the internal conditions are also not suitable for hibernating bats. Therefore, the current plans to demolish the majority of the building, with the exception of the administration building, will not directly impact on any bat hibernation roosts and therefore there will be no requirement to obtain a European Protected Species Mitigation (EPSM) Licence before demolition work can commence.

5.10. There is also no need for any further mitigation requirements. However, bats are known to be roosting in close proximity to the demolition works, in the summer, and therefore recommendations and precautions laid out in the previous summer survey report (Lloyd Bore, 2015, C468-RP01) and the method statement (Lloyd Bore, 2015, C468-RP02) should be adhered to.

17



18 JANUARY 2016

6. REFERENCES

Altringham, J.D. (2003) British Bats. Harper Collins, London

Bat Conservation Trust (2012) Bat surveys: Good Practice Guidelines. 2nd edition.

Dietz, C., Nill, D. & von Helversen, O. (2009) Bats of Britain, Europe and Northwest Africa. A

& C Black

IEEM (2006). Guidelines for ecological impact assessment in the United Kingdom. Institute of Ecology and Environmental Management, Winchester.

JNCC (2004). Bat Workers' Manual. 3rd edition.

Lloyd Bore (2015) C468-RP01 - Bat Survey Report: Finsley Gate

Lloyd Bore (2015) C468-RP02 - Method Statement (Bats) for Demolition Works at Finsley Gate Mill

Natural England (undated). Standing Advice Species Sheet: Bats

Waring. S (2015) Bats and Breathable Roofing Membranes. http://www.batsandbrms.co.uk/background.php (accessed 12/01/15)

18



18 JANUARY 2016

APPENDIX 1 PHOTOGRAPHS

Photo1: Northern elevation Photo 2: Eastern elevations

Photo 3: Lower ground floor Photo 4: Lower ground floor

Photo 5: Ground floor Photo 6: Ground Floor

Photo 7: Lower ground floor ceiling Photo 8: Ground floor ceiling

Lower ground floor

Ground floor

22



18 JANUARY 2016

APPENDIX 2 SURVEY PLAN (NOT TO SCALE)

Location of summer common pipistrelle roosts

Location of static detectors

Location of data logger

Main survey area / area of demolition (see appendix 3)

Anabat SD1 – Lower Ground Floor

Anabat Express –Ground Floor

23



18 JANUARY 2016

APPENDIX 3 DEMOLITION PLAN

(Taken from Finsley Gate Mill, Burnley, Demolition Specification: January 2015:

Rev : B: D05-128)

bat hibernation survey report - borough of … 0397 bat...bat hibernation survey report sk...

Documents