Appendix 10E. Studies and Surveys - Bats. Croxley Rail Link Volume 3 - Appendices. Appendix 10E - Ecology and Nature Conservation A 10E 1

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1 Appendix 10E Appendix 10E - Ecology and Nature Conservation A 10E 1

2 1 Introduction 1.1 Introduction This appendix details the findings of studies and surveys that have been undertaken to determine the potential presence of bats in the vicinity of the proposed Croxley Rail Link. 1.2 Scope of the Studies and Surveys The following studies and surveys have been undertaken: A desk-based review of existing records relative to the bats within a 1km study area centred on the proposed link; a review of aerial photographs of the proposed scheme corridor and neighbouring areas to aid identification of habitats potentially suitable for supporting roosting, commuting and foraging bats; tree and bridge inspections; re-entry surveys of trees activity surveys; automated static surveys; and manual static surveys. 1.3 Statutory Context All bat species in England and Wales are fully protected through inclusion within Schedule II of the Conservation of Habitats and Species Regulations Under the legislation they are given the status of a European protected species (EPS). The legislation makes it an offence to deliberately capture, kill, injure or disturb bat species. For the purposes of the legislation disturbance has been defined as that likely to: Impair their ability to: (i) Survive, breed or reproduce, or to rear or nurture their young; (ii) hibernate or migrate. Affect significantly the local distribution or abundance of that species to which they belong It is also an offence to damage or destroy a breeding site or resting place of bat species. It may be possible to apply for a licence from Natural England to allow activities that would otherwise be an offence under these Regulations All bats are also partially protected in England and Wales through their inclusion in Schedule 5 of the Wildlife and Countryside Act 1981 (as amended). Under this legislation it is an offence to intentionally or recklessly disturb a bat whilst it is using a place of rest or shelter and/or from being obstructed from entering such a place. This applies to Appendix 10E - Ecology and Nature Conservation A 10E 2

3 individuals, but is subject to a number of defences, including if the disturbance was the incidental result of a lawful operation that could not reasonably have been avoided. No licences are available for the purposes of development for offences under the Wildlife and Countryside Act 1981 (as amended). 1.4 Conservation Status There are 17 species of bat commonly found in the UK. It is widely recognised that all bat species, arguably with the exception of Daubenton s bat Myotis daubentonii, are declining and considered vulnerable throughout England and the rest of Europe (Mitchell-Jones, 2004). Consequently, certain bats are listed as UK and Hertfordshire Biodiversity Action Plan (BAP) priority species. There are seven bat species listed as UK BAP Priority Species: barbastelle bat Barbastella barbastellus, Bechstein's Bat Myotis bechsteinii, noctule Nyctalus noctula, soprano pipistrelle Pipistrellus pygmaeus, brown long-eared bat Plecotus auritus, greater horseshoe bat Rhinolophus ferrumequinum and lesser horseshoe bat Rhinolophus hipposideros. The Hertfordshire BAP includes one species of bat, the Natterer's bat Myotis nattereri By virtue of Section 74 CROW Act 2000 and Section 40 NERC Act 2006, all public authorities are obliged to take steps to further the conservation status of species of conservation concern in England. These species of conservation concern are taken as priority BAP species (section 74(4) CROW Act 2000). Appendix 10E - Ecology and Nature Conservation A 10E 3

4 2 Data Sources and Surveys 2.1 Desk Study The following data sources and organisations were referenced and contacted to establish current records relating to the presence of the species as part of the 1km desk-based review: Hertfordshire Biological Records Centre (HBRC); Hertfordshire & Middlesex Bat Group; London Underground ecological database; and National Biodiversity Network (NBN) Gateway ( 2.2 Field Surveys Field survey techniques, timing, effort and the sampling regimes used were selected in light of the guidance provided in Mitchell-Jones (2004) and the Bat Conservation Trust (BCT) (2007), to determine occupancy of habitats by bats. Bridge and Tree Inspections Bridge surveys were undertaken on 19th March 2010, 9th September 2010 and 17th May Ecologists systematically looked for evidence of bats (such as droppings, urine stains, scratch marks, feeding remains) in accordance with the guidance (BCT, 2007). The following bridges were inspected: 1) Baldwins Lane/Metropolitan Line Bridge; 2) Beggars Bush Lane/Disused Railway Line Bridge; 3) Ascot Road/Disused Railway Line Bridge; 4) Tolpits Lane/Disused Railway Line Bridge; 5) Vicarage Road//Disused Railway Line Bridge; 6) Cardiff Road/Stripling Way/Disused Railway Line Bridge; 7) Disused Railway Line Bridge over dry river bed; 8) River Colne (West)/Disused Railway Line Bridge; 9) River Colne (East)/Disused Railway Line Bridge; 10) Disused Railway Line Bridge over stream; and, 11) Wiggenhall Road Bridge The location of the bridges is shown in Figure Photographs of the bridges are available in Annex A to this Appendix Trees with potential to support bats were identified during walkover surveys undertaken on 27 th July 2009 and 9 th September Features Appendix 10E - Ecology and Nature Conservation A 10E 4

5 that could support roosts (including splits, cracks, and woodpecker holes) were recorded. Re-Entry Surveys of Trees Re-entry surveys of trees identified as having potential to support bats were completed during July 2011 which is within the optimal period to complete such work (see Table 10F-1; BCT 2007). Each tree was visited twice with visits beginning two hours before dawn and continuing until half an hour afterwards Surveyors used Batbox Duet bat detectors, with digital recordings made for later analysis of calls which could not be identified in the field. Recorded data were analysed on a PC using BatSound software, and species identification was guided by sonograms and data in Russ (1999). Activity Surveys Activity surveys were carried out using a mixture of walked transect routes and static vantage points along the transects. Transects and vantage points were positioned to cover habitats within the field survey area with the greatest potential for use by foraging or commuting bats. Habitats covered included woodland edge, hedgerows, tree lines, scrub, streams and riparian habitat. The use of vantage points enabled potential roosting structures to be surveyed for emerging bats. Underpasses and walkways crossing the proposed scheme corridor were also surveyed to identify if bats use these structures to cross the scheme. Three walked transects were defined: Appendix 10E - Ecology and Nature Conservation A 10E 5 Transect 1 along the disused railway line from Wiggenhall Road to the River Colne (West) disused railway line bridge and onto the Lairage Land LNR; Transect 2 along the disused railway line from Ascot Road to Tolpits Lane; and Transect 3 - along Baldwin s Lane, Watford Road, Beggars Bush Lane and Ascot Road, with particular focus on the area around the Grand Union Canal The locations of the three transects are shown in Figure The surveys were conducted by four surveyors working in pairs, each pair covering all three transects and associated vantage points in a single survey visit. Each transect was surveyed twice with surveys beginning 30 minutes before sunset and continuing until 2 hours afterwards. The surveys were completed during August and September 2009, the optimal period to complete such work (see Table 10F-1; BCT 2007) Surveyors used Batbox Duet bat detectors, with digital recordings made for later analysis of calls which could not be identified in the field. Recorded data were analysed on a PC using BatSound software, and

6 species identification was guided by sonograms and data in Russ (1999). For all bats encountered, notes were made of the location, species (where this could be determined from call sounds), and any behaviour that could be seen (e.g. direction and height of flight, circling, habitat in which they were observed etc.) or heard (e.g. feeding buzzes, social calls etc). The numbers of bats recorded during surveys of this nature do not accurately represent the actual bat populations present; however counts of bats do allow important foraging and commuting habitats to be identified and give an indication of distribution and behaviour of bats within the survey area. Automated Static Surveys To augment activity surveys, automatic bat detectors (Anabat SD1 units) were placed at points likely to be of value to bats. The detectors record bat activity in their surroundings which can be analysed using specialist software (Analook). Detectors were put out in August and September 2009 (see Table 3.1). Three Anabat units were used, and were placed in locations thought to offer potential foraging and commuting habitat for bats: Static Anabat Site 1 - Vicarage Road; Static Anabat Site 2 - Tolpits Lane; and Static Anabat Site 3 - Beggars Bush Lane, adjacent to the canal The locations of the static survey sites are shown In Figure Anabats were programmed to collect data starting half an hour prior to sunset, and were left recording overnight. Manual Static Survey An additional bat survey covering the Metropolitan Line crossing at Baldwins Lane was undertaken by two surveyors to see how bats use this area of the scheme. This area was considered important as it is where the proposed new railway line will connect by a viaduct to the Metropolitan Line. Two survey visits were undertaken on 14 th and 22 nd September 2010 by two surveyors (see Table 10F-1). For all bats encountered, notes were made of the location, species (where this could be determined from calls), and any behaviour that could be seen (e.g. direction and height of flight, circling, habitat in which they were observed etc) or heard (e.g. feeding buzzes, social calls etc). Appendix 10E - Ecology and Nature Conservation A 10E 6

7 Table 10F-1: Details of Bat Surveys Survey Type Survey Date Weather Sunset/rise Time Activity survey / static Anabat survey 10 Aug C, dry, overcast, breezy 20:34 Activity survey 13 Aug 2009 Static Anabat survey Static Anabat survey / manual static survey Manual static survey Re-entry Tree Survey Re-entry Tree Survey 20 C, dry, 60% cloud cover, still 20:28 9 Sep C, dry and still 19:30 14 Sep Sep Jul Jul C, overcast with some rain at start of survey and breezy 18 C, dry, scattered cloud cover and breezy 12 C, overcast with light rain at intervals, no wind. 8 C, dry, overcast, light wind 19:18 19:02 03:30 03:30 Limitations Access restrictions prevented a detailed walkover of the private land between the A412 and the Metropolitan Line at the western end of the proposed scheme corridor. Nevertheless, a visual search was undertaken from outside this land to identify trees with potential to support bat roosts. Access was also permitted to the London Underground database which holds some bat survey data for the Metropolitan Line from Owing to the size of the survey area and difficult access due to overgrown vegetation, it was difficult to survey the entire length of the disused rail section. As such, the static survey points were concentrated at key areas between transects that allowed greatest cover of rail line and / or concentrated upon potential bat commuting routes It is considered that these surveys give reasonable evidence of the presence / likely absence of bats and provide a good understanding of bat activity within the survey area. Biodiversity Value Biodiversity values for the species and indicative populations identified have been attributed in accordance with the guidelines recommended by the the Institute of Ecology and Environmental Management (IEEM) in its Guidelines for Ecological Impact Assessment in the United Kingdom (2006). The following value ratings have accordingly been adopted: Appendix 10E - Ecology and Nature Conservation A 10E 7 International - warranting designation as a Special Area of Conservation (SAC) or of conservation value at a European level;

8 National - warranting designation as a Site of Special Scientific Interest (SSSI) or of conservation value to England; Regional - of conservation value to the East of England; County - warranting designation as a County Wildlife Site or of conservation value to Hertfordshire; District - of conservation value to the district; Local - of conservation value within approximately 5km of the proposed Croxley Rail Link; and, Zone of Influence Only - of conservation value within the project site and its immediate surroundings. Appendix 10E - Ecology and Nature Conservation A 10E 8

9 3 Findings 3.1 Desk Study A search of HBRC revealed four species of bats: common pipistrelle Pipistrellus pipistrellus, Daubenton s bat, noctule and soprano pipistrelle within the study area, as summarised in Table 10F-2. Table 10F-2: Bat Records from within the Study Area from HBRC Species Date Location Distance from corridor 2004 Buddleia Forest & Pasture Croxley Green, Frankland Road 0.8 Common Pipistrelle 2002 Coningesby Drive, Watford British Waterways Office Watford High Street Bushey, Meadway 1.7 Daubenton s bat 2004 Grand Union Canal by Buddleia Forest & Pasture 1.2 Noctule 2004 Buddleia Forest & Pasture Coningesby Drive, Watford 1.2 Pipistrelle sp Oxhey Hall Area Soprano pipistrelle 2004 Buddleia Forest & Pasture Coningesby Drive, Watford A search of NBN revealed six species of bats: brown long-eared bat, common pipistrelle, Daubenton s bat, noctule, serotine Eptesicus serotinus and soprano pipistrelle to be present within the study area. These are summarised in Table 10F-3. Appendix 10E - Ecology and Nature Conservation A 10E 9

10 Table 10F-3: Bat Records from within the Study Area from NBN Species Date Location Distance from corridor Brown long-eared bat Watford and surrounding area Within same 10km 2 as proposed scheme corridor Common pipistrelle 2002 North of Eastbury At least 1.2km south of scheme Daubenton s bat 2004 West of Croxley Green At least 1.5km west of scheme Noctule Serotine North of Eastbury At least 1.2km south of scheme Soprano pipistrelle A search of London Underground s database found ecological survey data from studies undertaken in 2006 covering the Metropolitan Line land within the scheme. These surveys found that both embankments to the east of Baldwin s Lane and the northern embankment to the west of Baldwin s Lane provided suitable habitat, although bats were not confirmed as present. Also, a bat survey undertaken by Robert Stebbings Appendix 10E - Ecology and Nature Conservation A 10E 10

11 Consultancy Limited (unknown date) in connection with the Watford Junction Station EcIA highlighted that there was no evidence of bats in the trees, hedges or buildings that would be removed to enable construction Other data sources indicated the presence of a maternity roost of Common pipistrelle bats recorded at Croxley Marina Railway Bridge (TQ088961) on the opposite side of the canal at approximately 250m distance from the proposed scheme. Bats have also been recorded by the Hertfordshire and Middlesex Bat Group at the River Gade north of Croxley Green, usually around Cassiobury Park and West Hertfordshire Golf Course. 3.2 Field Survey Habitat Suitability Assessment Areas of the scheme contained woodland habitats which had the potential to contain bat roosts. The most significant of these areas are those where mature trees are located on the edge of the disused rail line, for example, the area of mature woodland at the western end of Cardiff Road that continues onto the embankment of the disused railway line. However, the vast majority of trees within the survey area were young, have a simple growth form and no damage, and were therefore of low likelihood of being of value to bats (Mitchell-Jones, 2004) A network of footpaths, tree lines, water courses and underpasses were located along the proposed site. These areas provide potential foraging and commuting corridors for bats, particularly where there was linear woodland with scrub vegetation mosaics, around underpasses (Vicarage Road and Tolpits Lane) and alongside waterways and associated riparian habitat (Grand Union Canal and River Gade). These linear features also connected other areas in the wider context such as the Grand Union Canal, Rivers Gade and Colne, Lairage Land Local Nature Reserve, Cassiobury Park and Croxley Common Moor SSSI. Inspection Surveys of Bridges (photos in Annex 1) The findings of the bridge surveys are scheduled in Table 10E-4. Appendix 10E - Ecology and Nature Conservation A 10E 11

12 Table 10E-4: Results of Bridge Inspections Location (1) Baldwins Lane/Metropolitan Line Bridge (2) Beggars Bush Lane/Disused Railway Line Bridge (3) Ascot Road/Disused Railway Line Bridge (4) Tolpits Lane/Disused Railway Line Bridge (5) Vicarage Road//Disused Railway Line Bridge (6) Cardiff Road/Stripling Way/Disused Railway Line Bridge (7) Disused Railway Line Bridge over dry river bed (8) River Colne (West)/Disused Railway Line Bridge Observations The Metropolitan Line Bridge crosses Baldwins Lane and is a single span metal bridge with brick abutments. The bridge was well maintained and was covered in wire mesh to exclude birds. The bridge had no obvious features suitable for supporting roosting bats. A double span metal bridge which crosses the Grand Union Canal, the River Gade and Beggars Bush Lane, with brick abutments. The bridge forms part of the disused railway line. The majority of this bridge was very open and exposed. The eastern-end abutment was covered in ivy, but it was not dense or mature enough to provide crevices to support roosting bats. There were no other obvious features suitable for supporting roosting bats. This single span bridge forms part of the disused railway line and crosses the Ascot Road. The bridge was constructed mainly from brick with some metal horizontal supports. Three brick arches running parallel provide additional support. There was some ivy covering the abutments, but it was not dense or mature enough to provide crevices to support roosting bats. There were no other obvious features suitable for supporting roosting bats. Tolpits Lane Bridge crosses over the disused railway line. The bridge is single span and was constructed mainly from brick with some metal horizontal supports. Three brick arches running parallel provide additional support. There was some ivy coverage of the abutments, but it was not dense or mature enough to provide crevices to support roosting bats. There were no other obvious features suitable for supporting roosting bats. Vicarage Road Bridge crosses the disused railway line. The bridge is single span and was constructed from brick with metal horizontal supports. Three brick arches running parallel provide additional support. There was some ivy coverage of the abutments, but it was not dense or mature enough to provide crevices to support roosting bats. There were no other obvious features suitable for supporting roosting bats. A single span bridge forming part of the disused railway line and crosses the footpath between Cardiff Road and Stripling Way. The bridge was constructed from brick. There is some ivy coverage of the abutments, but it was not dense or mature enough to provide crevices to support roosting bats. There were no other obvious features suitable for supporting roosting bats. A brick arch bridge forming part of the disused railway line and crossing an old river diversion that has long been dry. There was some ivy coverage of the abutments, but it was not dense or mature enough to provide crevices to support roosting bats. There were no other obvious features suitable for supporting roosting bats. This bridge forms part of the disused railway line and crosses the River Colne (West). The bridge is a single span metal bridge with three brick arches running parallel providing additional support. The abutments were constructed from brick. The bridge had no obvious features suitable for supporting roosting bats. Appendix 10E - Ecology and Nature Conservation A 10E 12

13 (9) River Colne (East)/Disused Railway Line Bridge (10) Disused Railway Line Bridge over stream (11) Wiggenhall Road Bridge Two parallel metal bridges cross the River Colne (East), with only 50cm clearance above the water. The southern bridge is constructed from brick with metal horizontal supports. The northern bridge is half constructed from brick and metal and the other half from concrete. Neither bridge had any obvious features suitable for supporting roosting bats. This bridge forms part of the disused railway line and crosses over a stream. The majority of the bridge is brick construction with metal support. There were no obvious features suitable for supporting roosting bats. The northern end of the bridge had been extended and there are cracks and crevices between the wooden beams, metal and brickwork. Theses could be used by crevice dwelling bats such as Pipistrelle species. However, the area was covered with cobwebs and there was no evidence of bats using the bridge such as droppings, clean gaps, urine stains, scratch marks or feeding remains. There was also dense vegetation at both ends of the bridge creating a cluttered environment not favoured by bats. Wiggenhall Road Bridge crosses over the disused railway line and is at the eastern end of the scheme. The bridge is a single span bridge constructed from brick with metal support. There was some ivy coverage of the abutments, but it was not dense or mature enough to provide crevices to support roosting bats. There were no other obvious features suitable for supporting roosting bats. Inspection Surveys of Trees The majority of trees present within the survey area were immature or semi-mature and do not contain features that could support roosting bats. However there are sections where mature trees were present, such as close to the River Colne (West), opposite the disused railway station platform at the end of Stripling Way and in the wet woodland between Ascot Road and the River Gade. Trees in these areas were assessed for their potential to support bats but none were found to possess features likely to support roosts. The trees on the Metropolitan Line embankments were visually assessed from Baldwins Lane but no features suitable for supporting roosting bats were identified South of the disused railway line, adjacent to Ascot Road is an area of hard standing that forms part of the scheme. On the western side of this hard standing there was a strip of semi-natural scrub habitat containing two mature oak trees. The northernmost of these was dead, with broken limbs, cavities and flaking bark, all of which are features that bats may use for roosting. The southern tree was alive and mature, but contained some cracks and broken limbs. The trees were fairly isolated in the landscape which limits their potential to support roosting bats. It was recommended that further surveys be carried out on the trees to confirm if the trees support a bat roost. Appendix 10E - Ecology and Nature Conservation A 10E 13

14 Re-Entry Surveys of Trees Surveys were undertaken under adequate weather conditions, being warm and without strong winds. The light rain encountered during the first survey was not significant enough to prevent bat activity No bats were seen re-entering roosts within the two mature trees adjacent to Ascot Road. These trees do not support bat roosts. Activity Surveys Transect 1 - Eastern End of Disused Railway Line During the first survey three bat species were recorded: common pipistrelle, soprano pipistrelle and noctule. A total of 16 contacts with bats were recorded during the survey. Of these the majority of records (8) were made up of common pipistrelle. These were recorded along the extent of the transect both feeding over the scrub, adjacent gardens and commuting along track ways. A single noctule pass was also recorded close to the centre of the transect, foraging and commuting over the disused rail track. Four soprano pipistrelle bats and three Pipistrelle sp. were also recorded along this transect. The first bat recorded passed at 21:03, foraging over scrub and trees close to the centre of the transect before flying eastwards. This bat was identified as a common pipistrelle. The noctule was recorded at 21: Similar levels of activity were recorded during the second visit to this transect with at least three bat species: common pipistrelle, soprano pipistrelle and Myotis species identified and a total of 15 passes. The majority of the contacts were made up of common pipistrelles. The first contact was made at 21:00 and was identified as a common pipistrelle. The Myotis bat was recorded at 21:42 approximately 1 hour 14 minutes following sunset. Transect 2 - Western End of Disused Railway Line During the first survey of this transect a total of 12 passes were made by three species of bat, the majority of which were soprano pipistrelle and common pipistrelle, with a single record of noctule. One record remained unidentified. Bats were noted foraging over isolated patches of scrub and around trees with the first bat recorded identified as a soprano pipistrelle at 20:59, approximately 25 minutes following sunset. The noctule was first recorded at 21: Only eight records were picked up during the second visit of this transect with the bats all being identified as soprano pipistrelles. The first bat was recorded at 20:49, approximately 21 minutes following sunset. The bats were recorded flying around buildings for a number of minutes located near the centre of the transect. Appendix 10E - Ecology and Nature Conservation A 10E 14

15 Transect 3 - Western End of Scheme This transect showed high levels of activity on both survey occasions, with 20 passes during the first visit. All records were identified as soprano pipistrelle and the first bat was recorded at approximately 21:55 with bats noted foraging along a treeline at the eastern extent of the transect. Other activity included foraging bats along the riparian habitat associated with the canal During the second survey 20 contacts were made consisting of at least three species. The dominant species recorded on this occasion was the soprano pipistrelle. Both common pipistrelle and Myotis sp. were also recorded with two calls not identified down to species level. The first bat was recorded at 21:18 and was identified as a soprano pipistrelle. Bats were noted circling around the old rail over bridge and foraging around gardens and over the canal in this location A summary of the activity survey results is shown in Table 10F-5. Table 10F-5: Summary of Activity Survey Data Number of bat passes recorded Transect Common pipistrelle Soprano pipistrelle Pipistrelle species Noctule Myotis sp Un- identified TOTAL Survey 1: 10/08/ Survey 2: 13/08/ Automated Static Surveys Site 1 - Vicarage Road Two species of bat were recorded during the first survey. This included two records of common pipistrelle and two records of soprano pipistrelle. The records occurred at 21:07 and 21:08 for the soprano pipistrelle. The common pipistrelle contacts were made at 21:12 and 21:15. No obvious feeding buzzes or social calls were noted. Appendix 10E - Ecology and Nature Conservation A 10E 15

16 During the second static survey at least three species of bat were recorded with a total of 38 contacts made. The majority of calls were unidentified with common pipistrelle dominant of the analysed calls. Soprano pipistrelle and a Myotis sp. were also recorded at this site. Calls were distributed throughout the survey time with notable peaks of activity occurring between 20:00 and 21:00 (29 contacts). No feeding or social calls were identified within the analysed data. The first species record occurred at 19:50 and was identified as a common pipistrelle bat. Site 2 - Tolpits Lane A total of 22 contacts were recorded during the first survey of this site and consisted of at least three species of bat including common pipistrelle, soprano pipistrelle and a noctule. The first call was recorded at 20:52 and could only be identified to the genus Pipistrellus. Activity was noted throughout the survey with a peak of 12 calls occurring between 21:00 and 22:00. Social calls were also noted from pipistrelle bats during the analysis of the data The second survey of this site recorded a total of 188 contacts with most contacts being identified to pipistrelle species. Highest levels of activity occurred between 19:00 and 20:00 (123 calls). Notable calls were logged every minute following the first registered record at 19:27. This call was identified as a common pipistrelle. Both pipistrelle species were recorded during this survey with nine records remaining unidentified. A number of social calls were also noted (14) during this survey. Site 3 - Beggars Bush Lane At least three species of bat were recorded during the first survey of this location with the pipistrelle species dominating. A single noctule was recorded late in the survey at 23:04 whilst eight records remained unidentified. The first contact during this survey was identified as a pipistrelle and occurred at 21:11. The peak counts in activity occurred between 21:00 and 22:00 with a total of 26 calls made during this time A total of 97 contacts were made during the follow up survey with 20 records identified as soprano pipistrelles. The remaining calls were not identified down to species level. This was due to a large proportion of the analysed data being made up of social calls only, without the distinctive echolocation signatures that would allow confident identification of the species. A total of 45 contacts contained social calling. The first record occurred at 19:54, approximately 24 minutes following sunset and was identified as a soprano pipistrelle A summary of the static survey results is shown in Table 10F-6 below. Appendix 10E - Ecology and Nature Conservation A 10E 16

17 Table 10F-6: Summary of Static Survey Data Number of bat passes recorded Transect Common pipistrelle Soprano pipistrelle Pipistrelle species Noctule Myotis sp Un- identified TOTAL Survey 1: 10/08/ Survey 2: 09/09/ Manual Static Surveys - Baldwins Lane/Metropolitan Line During the first survey, common pipistrelle and an unknown bat species were recorded. The first bat was picked up at 19:33 and was unidentified. The first common pipistrelle was picked up at 19:40. The first five passes were of common pipistrelle bats commuting both ways along the railway line. After this bats were recorded foraging in the woodland to the east and west of Baldwins Lane The second survey was very similar, with only common pipistrelle bats recorded. The first bat was recorded at 19:03, immediately after sunset. Bats were recording commuting parallel to the railway and foraging in the woodland either side. One bat was also recorded commuting over the railway bridge from south to north. 3.3 Field Survey Site Summary The surveys found no evidence of bats roosting within the survey area At least three bat species were identified during the activity surveys including: common pipistrelle, soprano pipistrelle, and noctule bats. In addition Myotis sp. were detected. Myotis bats were not identified to species level as positive identification of these species is difficult without visual observation of behaviour in combination with recordings. Appendix 10E - Ecology and Nature Conservation A 10E 17

18 3.3.3 The dominant species on almost all survey visits was the common pipistrelle and soprano pipistrelle, with the common pipistrelle more prevalent in the east of the site and majority of soprano pipistrelles recorded to the west of the site, particularly around the adjacent habitats of the canal. Noctule and Myotis sp. were also present in small numbers on some of the transects and static anabat sites, namely transect 1, transect 2, static Anabat site 2, static Anabat site 3 and transect 1, transect 3, static Anabat site 1 respectively. Common and soprano pipistrelles are widespread and common throughout Britain. Noctule bats are thought to be generally uncommon but more numerous in well wooded areas, whilst Myotis sp. bats vary from widespread and common (Daubenton s), widespread and fairly common (Natterer s), widespread and locally common (Whiskered and Brandts bat Myotis mystacinus/myotis brandtii) and restricted and very rare (Bechsteins) (BCT, 2009) The surveys revealed that common and soprano pipistrelles and a number of other species are present throughout the survey area and especially in habitats adjacent to the disused rail line, particularly the scrub found throughout the site. Other areas of importance for foraging include the adjacent riparian habitat located around the River Colne and Grand Union Canal. Important areas of activity included high levels of social behaviour around Tolpits Lane and Beggars Bush Lane, with particular activity from Myotis bats in and around areas of Vicarage Road, Grand Union Canal and woodland / riparian habitat of the River Colne. Noctule bats were recorded in low numbers across the whole survey area foraging high over the scrub associated with the rail line. Bats were observed using habitats adjacent to the rail line for feeding, commuting and socializing. No bats were noted swarming or emerging from trees / structures during surveys, however due to the relatively short delay between the onset of dusk and the bats appearance during the survey, it is presumed that the bats originate from a roost situated near to the scheme. 3.4 Evaluation The surveys found no evidence of bats roosting within the survey area. The survey area is of negligible biodiversity value for roosting bats The activity surveys recorded predominately common and widespread species such as the common and soprano pipistrelle. A significant number of bats and high levels of bat social activity was noted around Tolpits Lane and the Grand Union Canal. These two areas are considered of at least biodiversity value at a local level for bats. The remaining sections of the survey area support fewer bats and are of value at no more than the zone of influence for the proposed scheme. Appendix 10E - Ecology and Nature Conservation A 10E 18

19 References Bat Conservation Trust (BCT). (2007). Bat Surveys Good Practice Guidelines. BCT, London. Bat Conservation Trust, (2009). The National Bat Monitoring Programme Annual Report JNCC. IEEM, (2006). Guidelines for Ecological Impact Assessment in the United Kingdom. Institute of Ecology and Environmental Management, Winchester. Mitchell-Jones, A.J. (2004). Bat Mitigation Guidelines. English Nature, Peterborough. Russ The Bats of Britain and Ireland. Echolocation Calls, Sound Analysis and Species Identification. Alana Books. Appendix 10E - Ecology and Nature Conservation A 10E 19

20 Annex A: Photographs Bridge 1 - Baldwins Lane Bridge. Bridge 2 - Beggars Bush Lane. Bridge 3 Ascot Road Bridge. Bridge 4 Tolpits Lane Bridge. Bridge 5 Vicarage Road Bridge Bridge 6 Cardiff Road/Stripling Way Bridge Appendix 10E - Ecology and Nature Conservation A 10E 20

21 Bridge 7 - Dry River Bridge. Bridge 8 - River Colne (West) Bridge. Bridge 9 - River Colne (East) Bridge. Bridge 10 - Stream Bridge. Bridge 11 - Wiggenhall Bridge. Appendix 10E - Ecology and Nature Conservation A 10E 21