BLACKDOWN HILLS 2015 BIG BAT SURVEY

Transcription

1 BLACKDOWN HILLS 2015 BIG BAT SURVEY

2 Contents Summary... 3 Acknowledgements INTRODUCTION METHOD Training and Survey Sound Analysis Limitations of the Survey RESULTS AND SOUND ANALYSIS Overall summary Bat passes recorded along each transect route Transect 1: Buckland Wood and Quants Transect 2: Sampford and Black Down Commons Transect 3: Bolham Water Transect 4: Castle Neroche Transect 5: Otterford Lakes Transect 6: Staple Hill Plantations Transect 7: Thurlbear Transect 8: Dunkeswell Transect 9: Yarcombe Transect 10: Membury Transect 11: Wambrook Transect 12: White Staunton Transect 13: Broadhembury Transect 14: Upottery Transect 15: Cotleigh Transect 16: Netherclay... 55

3 Summary The fifth Blackdown Hills Big Bat Survey was run by the Somerset Environmental Records Centre (SERC) with the help and support of the Somerset Bat Group (SBG) and the Blackdown Hills Area of Outstanding Natural Beauty Partnership (Blackdown Hills AONB). It was made possible with the generous financial support of the Blackdown Hills AONB through their Sustainable Development Fund. Without these three bodies it would not have been possible. Equally, the whole survey depended on the enthusiasm and expertise of an army of volunteers giving their time to design and walk transects, stumble about in the dark and spend hours at a computer analysing the results. The second greatest number of bat passes was recorded in 2015 with 3448 passes, second to the number of passes recorded in 2012 at 3952 passes. Common Pipistrelle Bats remain the most frequently recorded bats, and the percentage share of passes from this species increased to 73% of the total recorded passes. Soprano Pipistrelle Bats were the second most recorded species followed by Myotis sp. in third. These latter two species/groups have swapped places since the 2011 survey where Myotis sp. were recorded much more frequently than Soprano Pipistrelle Bats. Serotine and Noctule Bats were recorded, but in lower numbers of passes compared with previous years, and Leislers Bat was not recorded at all in The number of Barbastelle Bats has been relatively constant, apart from a low number of passes in 2012, and the number of passes by Long-eared Bats has increased, which may be partly due to better analysis of the recordings and familiarity with their calls. The number of Lesser Horseshoe Bat passes doubled in compared with the first three years of survey Finally, the unexpected surprise of the survey was a Nathusius Pipistrelle pass recorded along the Wambrook transect, as this species is more often associated foraging over large waterbodies the location is unexpected, but it may have been a commuting bat as Nathusius Pipistrelles are known to travel large distances. Acknowledgements Special thanks to all of the volunteers who took part in the survey: Colin Banfield, Pete Banfield, Conrad Barrowclough, Linda Bennett, Nick Bentley, Liz Biron, Simon Breeze, Sarah Butcher, Greg Colthorpe, Dave Cottle, Jeremy Cuff, Kathleen Cuff, Emily Forbes, Neil Gemmell, John Godsmark, Valerie Godsmark, Alasdair Grant, Belinda Howell, Daryl Hughes, Rachel Hume, Mark Huntington, Dot Isgrove, Naomi Johnson, Ania Jurkowska, Alan Keith, Paul Kennedy, Monique Kors, Penny Lawrence, Philip Lewenz, David Lloyd, James Maben, Matthew Marshall, Holly McGovern, Will Molyneaux, Hannah Montag, Gregor Neeve, Tom Nitti, Ken Pearson, Lizzy Porter, Laura Quinlan, Bonaventure Ralph, Matt Reynolds, Clive Sabel, Cath Shellswell, Alan Shuttleworth, Julie Steed, Lorne Thompson, Edward Wells, Helen Wells, Richard Winn and Louise Woolley. All the land holders that allowed the survey to take place around their holding. Transects were created in 2011 and 2012 by Cath Shellswell, Lou Pickersgill, Edward Wells and Liz Biron. Sound analysis undertaken using BatSound by Edward Wells and Cath Shellswell GIS analysis undertaken using ESRI ArcGIS 9.2 by Cath Shellswell Cover photograph: Natterers Bat Paul Kennedy Report Authors: Edward Wells, Laura Quinlan and Cath Shellswell.

4 1. INTRODUCTION There are 17 species of bat known to breed in Britain and 16 of those are recorded in Somerset and Devon. Whilst a number of specific bat roosts within the Blackdown Hills AONB have been known for many years, the way in which bats use the landscape of this interesting and varied part of Somerset and Devon has been only sparsely studied. Flight records have been largely anecdotal. A survey for the National Bat Monitoring Programme of the Bat Conservation Trust in 2010 and 2011 revealed a number of sites for the nationally rare Bechstein s Bat (Myotis bechsteinii) in and near the Blackdown Hills. Clearly the area could be of great importance for bats. As bats are highly mobile, their presence is a good indicator of the status of habitats and they can be used to monitor changes in the condition of the wider landscape. Habitat degradation, such as Intensive land management, can deplete the invertebrate population and bats will move elsewhere. The way that the different bat species use the environment, particularly in relation to the use of linear landscape features to commute and feed opportunistically, is still a matter of research and debate but it can only help inform that debate to have comparative data covering a number of years showing where in the landscape bats are encountered. The Blackdown Hills represent an outstanding area in which to collect such data with their un-intensive land use and varied mosaic of habitats supported through high nature value farming and forestry. In order to improve knowledge of the way in which the landscape of the Blackdown Hills AONB is used by bats, the AONB commissioned SERC in 2011 to carry out a Batscapes study, using aerial photograph interpretation and the Integrated Habitats System (IHS), to map and predict areas likely to be suitable for the various British bat species. This work produced predictive maps for a number of species based on their known habitat requirements and on the distribution of known records. In addition to other Big Bat Surveys, the Somerset Bat Group undertook the development of a similar concept in the Blackdown Hills, supported by the AONB with the coordination contracted to SERC in The Blackdown Hills Big Bat Survey was designed following the model of the highly successful Mendip Hills Big Bat Survey. The predictive maps produced in the Batscapes study were used to identify potentially good areas to survey. The survey method employed was a transect method with the actual routes used selected according to their practicality. Public paths were an essential part of the transect routes and public roads were avoided wherever possible. It was essential that the chosen route should be safe and able to be negotiated within a reasonable time. The methods employed were designed to minimise any impacts on bats, essential to ensure validity of the results. The transects were not walked by large groups of people; groups consisted mostly of 4 or 5 people, walking carefully and quietly to not cause a significant intrusion. The potential impact of bats responding to the sounds from bat detectors was also considered this is at a much lower frequency than the sound of actual bat calls. It is generally believed that bats do not associate the noises from bat detectors with their own sounds; however, if they do, there is no evidence available to indicate that they alter their behaviour in any way when active within hearing of a bat detector. Therefore, small groups of people walking the transects with bat detectors was considered suitable for obtaining valid results. It was equally essential that the survey did not disturb or put at risk any other wildlife, or any landowners, their livestock or their crops. Although the transects are along open access footpaths, all landowners were contacted prior to the survey to make them aware that the event was going ahead and the police were also informed to make sure that the unusual activity (and lights) did not raise alarm. The survey has been held annually for five years and has always attracted over 60 people. The early popularity and success of the project enabled the number of transects to be increased from 12 to 16 routes in 2012 onwards. Much of the purpose of repeating a survey of this kind over a number of years is to try to iron out inconsistencies caused by variable factors such as weather and farming practice. In order to correct for differences caused by the time after sunset a particular area was surveyed the routes were walked in reverse in alternate years. Thus, in 2011, 2013 and 2015 the transect began at walk 1 and finished at point 6 (termed NORMAL direction); in 2012 and 2014 the transect began at point 6 and finished at walk 1 (termed REVERSE direction). The Blackdown Hills Big Bat Survey, whilst providing a significant body of robust and meaningful data, also provided an opportunity for a large number of people to experience the pleasure of listening for bats in the company of more experienced bat people. Local naturalists have discovered a whole new world in their own neighbourhood, a world which only comes to life when the sun has gone down.

5 2. METHOD The 2015 Blackdowns Big Bat Survey is a landscape survey to collect comparable data across the Area of Outstanding Natural Beauty: (a) 16 predetermined routes (figure 1) were walked simultaneously comprising a series of 6 walking sections and 6 stationary points. Each team of volunteers listened to bats using heterodyne or frequency division bat detectors and listed what they heard in each section. (b) At the same time one person in each group undertook a continuous recording on a wave recorder (such as a Zoom or Edirol recorder) using a frequency division Batbox Duet Detector. The recordings were assigned to separate tracks for each section and then analysed to count the number of bat passes in each section and, so far as possible, assign those passes to species. 2.1 Training and Survey Before the survey took place, Edward Wells ran a workshop on the 26 th June 2015 to help inexperienced volunteers become acquainted with how to interpret the calls that they would hear whilst using a bat detector during the survey. Sixteen transects were surveyed on 17 th of July The volunteers were divided between the selected transects, with a minimum of two people per transect but the majority of groups consisting of four to six volunteers. Heterodyne bat detectors were leant to volunteers who did not have their own detectors. All surveys were completed and good frequency division sound data was collected from each route. Each walk consisted of six stops of five minutes and six walked sections lasting an average of about ten minutes. The stops were chosen strategically where there were potentially significant landscape features and the walks were mainly along established footpaths for the comfort and safety of the volunteers. Each transect was walked to the route followed in 2011 and latterly 2013 to ascertain whether there are differences in bat activity depending on the time of evening. For clarity in comparing years, on the maps and tables of this report the numbering of stops and walks has been shown the same for both years and a note has been made for the years when the survey was walked in reverse. All landowners along each transect were asked for permission to access their land. To create each route, a walk was drafted using OS Explorer Map 115, 116 and 128. The transects were subsequently checked to measure the timings of each section at a steady walking pace and define the different habitats at the stops. The volunteers were provided with maps of the transect they were undertaking, a risk assessment and asked to walk the route in daylight to familiarise themselves with the route for safety prior to the survey. Further information that was provided to volunteers is available from the Somerset Environmental Record Centre. Before starting the surveys, the volunteers met for a brief health and safety talk and then travelled to the beginning of each transect. Individuals with a mixture of bat experience from beginner to very experienced were assigned to each group. One person in each group recorded the route continuously using a Batbox Duet and a wave recorder. The surveys started at 21:30 and finished at approximately 23:30. A chosen volunteer in each group travelled to the Cricket Pavilion at Churchinford to hand in the recordings and survey forms. 2.2 Sound Analysis The number of bat passes made by each species or group was counted to provide a measure of bat activity along each walk section and stop section. A bat pass is a continuous stream of echolocation calls indicating a bat flying past. The number of bat passes is therefore best understood as an index of bat activity rather than the absolute number of bats in the area. Except for the bats of the genus Myotis, and Plecotus each species has a spectrogram which is usually distinctive. 2.3 Limitations of the Survey There are several factors that may affect the results and comparison between the routes: Differences in the range of individual bat detectors individual detectors of the same type can vary in range depending on factors such as local environmental conditions and battery strength. To minimise this effect, new batteries can be used.

6 Changes in environmental conditions, such as daylight length and factors relating to the stage in the breeding season, can be compensated for by carrying out the surveys at the same time on the same night. However, less predictable factors, such as temperature, wind speed and direction, and levels of precipitation before and during the survey, all of which will affect invertebrate activity and thus bat activity, are less easy to compensate for and thus may affect the results. Observer error misidentifying bat passes and counting the number of bat passes the standard procedure for counting bat passes was followed; however there is scope for error if more than one bat of the same species / genus is passing the bat detector at one time. There is also the potential to misidentify species, particularly if the call is faint. Human error in several previous years transects no analysable recordings were obtained. In that situation we have relied on the written notes. There is a lower level of confidence in the identification of the species missed in this way but given the experience of the recorders concerned we considered it appropriate to accept their identification even though it could not be subjected to objective verification by sound analysis. There is a greater danger of inaccuracies in identifying species from bat passes from heterodyne recordings, and individual bat passes are more difficult to distinguish if more than one bat is flying past the bat detector at the same time resulting in counting errors. There is also a greater risk that bat species echolocating at different frequencies may be missed, for example, heterodyne detectors are unlikely to pick-up both a Noctule Bat pass and Lesser Horseshoe Bat pass at the same time as the difference in frequency is too large if the detector is tuned to either the lower or higher end of the spectrum. On another transect the team missed their route during Walk 4. These anomalies are explained in the appropriate comments. Faint recordings on a number of transects some of the echolocation calls on the recording were too faint to identify the bat species. Faint recordings also make it difficult to extract a peak frequency for the echolocation calls of pipistrelle species. Where the genus of bat was uncertain the recording is marked in the report as bat species and where there is sufficient confidence to assign a recording to the genus Pipistrellus but not to a species the recording is marked as Pipistrelle species. Differences in range of bat echolocation calls certain bat species may echolocate particularly quietly, for example Barbastelle Bat, or may not echolocate at all and use passive hearing, for example Long-eared Bats, or may have a particularly high echolocation frequency which may not travel as far compared with lower frequencies, for example Horseshoe Bats. This affects the capacity of the detector to pick-up and record bat passes unless the bat is close, and as a consequence some species may be recorded less frequently than other species.

7 Figure 1: Map of the bat transects undertaken as part of the Blackdowns Big Bat Survey

8 3. RESULTS AND SOUND ANALYSIS 3.1 Overall summary Common Pipistrelles consistently account for about 70% of the passes recorded on the Blackdown Hills surveys. There appears to be a rise in the number of Soprano Pipistrelle passes over the five years from 5.3% and 8% in the first two years to 12-14% now. Soprano Pipistrelles are often associated with bodies of water but, with the exception of Otterford Lakes, there are few such features on these transects. If they are increasing, and passes do not mean more bats only more activity, then it is certainly not at the expense of Common Pipistrelles over the survey as a whole. The first pass of a Nathusius Pipistrelle was recorded along the Wambrook transect. This species is associated with large water bodies, and has been recorded over Blagdon Lake in North Somerset. It is a migratory species and perhaps it was travelling to a favoured feeding location as there are no large water bodies near the Wambrook transect. More worrying is the reduction in Myotis sp. Bat passes from 19% in 2011 to 5.8% in It is difficult to tell whether that is a genuine change. There are some obviously atypical cases such as in 2012 at Netherclay but reduced Myotis activity seems to be a steady trend in a number of areas; Bolham Water, Otterford Lakes and Castle Neroche for instance. We continue to find fewer big bats than expected. Noctules in particular seem hard to find and Serotines are inconsistent. The steady increase in Barbastelle passes may be genuine or may reflect a greater willingness on the part of the sound analyst to identify this relatively uncommon species. Long-eared Bat sp. recordings increased dramatically from three passes in 2011 to fourteen passes in Recordings for Long-eared passes seem inconsistent through the five years of this survey. This could be due to their faint echolocation call which can be hard to pick up when analysing the sound recordings. Another reason why the number of Long-eared passes may have increased is the greater experience of the sound analysers throughout the period of the Big Bat Survey. Horseshoe bats have been increasing in frequency from five passes in 2011 to nine passes in However, due to the limited amount of calls recorded, it is hard to say for certain if there has been a significant increase of Horseshoe Bat numbers over the five years of the survey. Table 1 shows the number of bat passes and proportion of total calls for all the species recorded, and the following maps show the cumulative presence of species recorded across the Blackdown Hills. The results only show presence of bats identified from the recordings and cannot indicate the absence of a particular species as the survey does not cover the entirety of each square kilometre, and, as a consequence, there is the possibility that species may have been missed. The following maps show the presence of each species within each monad surveyed in the Blackdown Hills between Table 1: Number and proportion of bat passes recorded for each species / group. Species / Species Group 2011 Bat Passes 2011 Total (%) 2012 Bat Passes 2012 Total (%) 2013 Bat Passes 2013 Total (%) Lesser Horseshoe Common 45 Pipistrelle Soprano 55 Pipistrelle Nathusius' Pipistrelle Pipistrelle sp Serotine Noctule < Leisler's <0.1 Myotis sp Long-eared bat sp Barbastelle < Unidentified bat species TOTAL

9 Species / Species Group 2014 Bat Passes 2014 Total (%) 2015 Bat passes 2015 Total (%) Lesser Horseshoe Common 45 Pipistrelle Soprano 55 Pipistrelle Nathusius' Pipistrelle <0.1 Pipistrelle sp Serotine Noctule Leisler's Myotis sp Long-eared bat sp Barbastelle Unidentified bat species TOTAL Bat passes recorded along each transect route The recordings from each transect were analysed separately and divided into the walk and stop sections shown in the following tables and maps. It is, of course, impossible to draw any firm conclusions from data collected on one night only and the following observations must be treated with caution. Five years of surveying can however allow some tentative comparisons and at least show those areas which appear to be consistently used by large numbers of bats.

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14 3.2.1 Transect 1: Buckland Wood and Quants Year Bat species Transect section Walk 1 Stop 1 Walk 2 Stop 2 Walk 3 Stop 3 Walk 4 Stop 4 Walk 5 Stop 5 Walk 6 Stop 6 Total Pipistrelle Myotis sp Unidentified bat passes * Lesser Horseshoe Pipistrelle Myotis sp Unidentified bat passes Lesser Horseshoe Pipistrelle Pipistrelle 1 1 Myotis sp Serotine 5 5 Unidentified bat passes * 45 Pipistrelle Myotis sp Pipistrelle Pipistrelle Pipistrelle sp Myotis sp Long-eared bat sp Unidentified bat passes * The 2012 and 2014 surveys were completed in reverse starting at Stop 6 and finishing at Walk 1. This transect recorded its best year so far, with Common Pipistrelles active in every part of the transect except Stop 6. In 2013, when the route was last followed in this direction, the hot spot was Walk 2 with 54 Common Pipistrelle passes but this time the spread of activity was much more even with no one section recording more than 29 passes. Myotis bats have been recorded at Walk 3 in four out of five years.

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16 3.2.2 Transect 2: Sampford and Black Down Commons Year Bat species Transect section Walk 1 Stop 1 Walk 2 Stop 2 Walk 3 Stop 3 Walk 4 Stop 4 Walk 5 Stop 5 Walk 6 Stop 6 Total Pipistrelle Myotis sp Serotine Unidentified bat passes * 45 Pipistrelle Pipistrelle sp Pipistrelle Pipistrelle Pipistrelle sp Myotis sp Unidentified bat passes * 45 Pipistrelle Pipistrelle Serotine Myotis sp Unidentified bat passes Pipistrelle Pipistrelle Pipistrelle sp Myotis sp Long-eared bat sp 1 1 Unidentified bat passes * The 2012 and 2014 surveys were completed in reverse starting at Stop 6 and finishing at Walk 1. Fewer bat passes were recorded than in the last two years, but still well up on the activity in 2011 and In three of the previous four years there have been Pipistrelles of both common species (Common and Soprano Pipistrelles) in the middle part of the transect over the heathland and by the pond. In 2015 they seem to have been in the wooded habitat at the start and end of the walk. The temperature was cooler in 2015 than in the previous two years and that might be significant as may be the condition of the pond which was reported as muddy and lifeless, suggesting that there were few insects present.

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18 3.2.3 Transect 3: Bolham Water Year Bat species Transect section Walk 1 Stop 1 Walk 2 Stop 2 Walk 3 Stop 3 Walk 4 Stop 4 Walk 5 Stop 5 Walk 6 Stop 6 Total Pipistrelle Pipistrelle Myotis sp Serotine 5 5 Unidentified bat passes * 45 Pipistrelle Pipistrelle Pipistrelle sp Myotis sp Unidentified bat passes Pipistrelle Pipistrelle Pipistrelle sp Myotis sp Unidentified bat passes * 45 Pipistrelle Pipistrelle Myotis sp Unidentified bat passes Pipistrelle Pipistrelle Pipistrelle sp 3 3 Serotine Myotis sp Unidentified bat passes * The 2012 and 2014 surveys were completed in reverse starting at Stop 6 and finishing at Walk 1.

19 This has always been a rich transect especially for Common Pipistrelles. This year s total of 206 passes was 74 more than 2014 although still well short of the total in The return of Serotines was welcome as this is good livestock farming country where they should be in evidence. The status of Myotis bats is of slight concern with a mere 15 passes as against 65, 70 and 61 in the previous 3 years. This poses the question Why should this be? and, if the survey is repeated in 2016, Is this pattern going to occur again?

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21 3.2.4 Transect 4: Castle Neroche Year Bat species Transect section Walk 1 Stop 1 Walk 2 Stop 2 Walk 3 Stop 3 Walk 4 Stop 4 Walk 5 Stop 5 Walk 6 Stop 6 Total 2011 Lesser Horseshoe Pipistrelle Pipistrelle Pipistrelle sp Myotis sp Barbastelle Unidentified bat passes * Lesser Horseshoe Pipistrelle Pipistrelle sp 1 1 Myotis sp Serotine 2 2 Unidentified bat passes Pipistrelle Pipistrelle Pipistrelle sp Myotis sp Serotine Barbastelle Unidentified bat passes * 45 Pipistrelle Pipistrelle Pipistrelle sp Myotis sp Long-eared bat sp 2 2 Unidentified bat passes

22 Year Bat species Transect section Walk 1 Stop 1 Walk 2 Stop 2 Walk 3 Stop 3 Walk 4 Stop 4 Walk 5 Stop 5 Walk 6 Stop 6 Total Pipistrelle Pipistrelle Pipistrelle sp Serotine 3 3 Myotis sp Barbastelle 5 5 Unidentified bat passes * The 2012 and 2014 surveys were completed in reverse starting at Stop 6 and finishing at Walk 1. The late Lou Pickersgill who designed this transect and walked it for the first few years had a particular affection for Barbastelles and they did not disappoint. The Barbastelle passes were in a different part of the transect from the previous years but these are very mobile bats with a history of flying long distances to feed. The total of 347 Common Pipistrelle passes is outstanding but there were very few Myotis bats. One other factor to consider is why have Noctules not been recorded in the transect when the habitat would appear ideal for them.

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24 3.2.5 Transect 5: Otterford Lakes Year Bat species Transect section Walk 1 Stop 1 Walk 2 Stop 2 Walk 3 Stop 3 Walk 4 Stop 4 Walk 5 Stop 5 Walk 6 Stop 6 Total Pipistrelle Pipistrelle Myotis sp Noctule Serotine Unidentified bat passes * 45 Pipistrelle Pipistrelle Myotis sp Serotine Long-eared bat sp 1 1 Unidentified bat passes Pipistrelle Pipistrelle Pipistrelle sp 2 2 Myotis sp Noctule 1 1 Unidentified bat passes * 45 Pipistrelle Pipistrelle Pipistrelle sp 2 2 Myotis sp Serotine Barbastelle 1 1 Unidentified bat passes

25 Year Bat species Transect section Walk 1 Stop 1 Walk 2 Stop 2 Walk 3 Stop 3 Walk 4 Stop 4 Walk 5 Stop 5 Walk 6 Stop 6 Total Pipistrelle Pipistrelle Pipistrelle sp 1 1 Serotine Noctule Myotis sp Unidentified bat passes * The 2012 and 2014 surveys were completed in reverse starting at Stop 6 and finishing at Walk 1. An excellent total of 422 Common Pipistrelle passes, but it is surprising that this time they seem to be throughout even on the less favourable road sections at Walk 6 and Stop 6. The Myotis and Noctule bats were recorded by the lakes themselves as one would expect, but the number of passes was not high. In 2012 there were 111 Soprano Pipistrelle passes and 155 Myotis ones. 22 and 39 respectively this year is much more like One explanation is that Daubentons Bats, which are the most likely Myotis species over water, emerge late and in reverse years the surveyors have been arriving at the lakes too early.

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27 3.2.6 Transect 6: Staple Hill Plantations Year Bat species Transect section Walk 1 Stop 1 Walk 2 Stop 2 Walk 3 Stop 3 Walk 4 Stop 4 Walk 5 Stop 5 Walk 6 Stop 6 Total Pipistrelle Myotis sp Serotine Unidentified bat passes * Lesser Horseshoe Pipistrelle Myotis sp Unidentified bat passes Pipistrelle Pipistrelle 4 4 Myotis sp Serotine 4 4 Unidentified bat passes * 45 Pipistrelle Pipistrelle Not Myotis sp recorded Serotine Unidentified bat passes Pipistrelle Pipistrelle sp Noctule 1 1 Myotis sp Barbastelle 1 1 Unidentified bat passes * The 2012 and 2014 surveys were completed in reverse starting at Stop 6 and finishing at Walk 1. This is never a very busy transect and part of it at least is quite exposed. Whilst the evening was still, it was cooler and less humid than in 2013 and That may have reduced bat activity. Stop 1 has not recorded a single pass in 5 years even when the route has been reversed. It would appear to be a relatively unused part of the landscape by bats whatever the weather. Generally the results here are fairly consistent and the high point in 2015 was a Barbastelle.

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29 3.2.7 Transect 7: Thurlbear Year Bat species Transect section Walk 1 Stop 1 Walk 2 Stop 2 Walk 3 Stop 3 Walk 4 Stop 4 Walk 5 Stop 5 Walk 6 Stop 6 Total Pipistrelle Pipistrelle Pipistrelle sp 1 1 Myotis sp Noctule Serotine * Unidentified bat passes Pipistrelle Pipistrelle This portion of the survey was missed in Pipistrelle sp Myotis sp Unidentified bat passes Pipistrelle Pipistrelle Pipistrelle sp 1 1 Myotis sp Serotine Noctule * 45 Pipistrelle Pipistrelle Myotis sp Barbastelle 2 2 Unidentified bat passes

30 Year Bat species Transect section Walk 1 Stop 1 Walk 2 Stop 2 Walk 3 Stop 3 Walk 4 Stop 4 Walk 5 Stop 5 Walk 6 Stop 6 Total Pipistrelle Pipistrelle Pipistrelle sp 1 1 Serotine Myotis sp Long-eared bat sp 1 1 Unidentified bat passes * The 2012 and 2014 surveys were completed in reverse starting at Stop 6 and finishing at Walk 1. The pattern of activity in this transect is consistent across the years with the richest section being Walk 4. That accounted for nearly half the Common Pipistrelle passes and over three quarters of the Soprano Pipistrelle ones. However the surveyors did have difficulty navigating this section and the recording is longer than it was in other years. There were no Barbastelles this time and no Noctules for the second year running. The habitat seems ideal for Noctules so their absence is puzzling. There are few passes even though this wood is known to contain Bechsteins Bats.

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32 3.2.8 Transect 8: Dunkeswell Year Bat species Transect section Walk 1 Stop 1 Walk 2 Stop 2 Walk 3 Stop 3 Walk 4 Stop 4 Walk 5 Stop 5 Walk 6 Stop 6 Total Pipistrelle Pipistrelle 3 3 Myotis sp Noctule 2 2 Serotine Unidentified bat passes * 45 Pipistrelle Pipistrelle Myotis sp Noctule 1 1 Long-eared bat sp Unidentified bat passes Pipistrelle Pipistrelle Pipistrelle sp Myotis sp Serotine Noctule 1 1 Unidentified bat passes * 45 Pipistrelle Myotis sp Serotine 2 2 Barbastelle Long-eared bat sp 2 2 Unidentified bat passes 1 1 2

33 Year Bat species Transect section Walk 1 Stop 1 Walk 2 Stop 2 Walk 3 Stop 3 Walk 4 Stop 4 Walk 5 Stop 5 Walk 6 Stop 6 Total Pipistrelle Pipistrelle Pipistrelle sp Serotine 1 1 Noctule 1 1 Myotis sp Unidentified bat passes * The 2012 and 2014 surveys were completed in reverse starting at Stop 6 and finishing at Walk 1. Another somewhat exposed site but this time showing no Barbastelles, Noctules or Serotines all of which hunt over heaths. This transect usually has high numbers of Myotis passes particularly in reverse years, so 18 in 2015 is less than expected. The completely unexpected result this year is the apparent reversal in numbers between the two common Pipistrelle species. In 2011 there were 385 Common Pipistrelle passes and 3 Soprano Pipistrelle; in 2014 there were 91 to nil. In 2015 there were only 27 Common Pipistrelle passes and 53 Soprano Pipistrelle ones. More data might reveal whether there has been a change. The two species often feed together without either seeming to exclude the other.

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35 3.2.9 Transect 9: Yarcombe Year Bat species Transect section Walk 1 Stop 1 Walk 2 Stop 2 Walk 3 Stop 3 Walk 4 Stop 4 Walk 5 Stop 5 Walk 6 Stop 6 Total Pipistrelle Pipistrelle 3 3 Myotis sp Serotine Barbastelle Unidentified bat passes * 45 Pipistrelle Myotis sp Serotine 3 3 Unidentified bat passes Pipistrelle Pipistrelle Myotis sp Serotine Unidentified bat passes * 45 Pipistrelle Pipistrelle Pipistrelle sp Myotis sp Noctule 1 1 Unidentified bat passes

36 Year Bat species Transect section Walk 1 Stop 1 Walk 2 Stop 2 Walk 3 Stop 3 Walk 4 Stop 4 Walk 5 Stop 5 Walk 6 Stop 6 Total Pipistrelle Pipistrelle Pipistrelle sp Serotine Myotis sp Barbastelle 2 2 Unidentified bat passes * The 2012 and 2014 surveys were completed in reverse starting at Stop 6 and finishing at Walk 1. Another Barbastelle was recorded along this transect, but whereas in 2011 it was at Walk 5, in 2015 the passes were right at the beginning in Walk 1. The pattern of where bats are most active is consistent year on year, with Stop 3 always quiet. This transect is one that seems to vary little regardless of weather conditions or direction in which it is walked.

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38 Transect 10: Membury Year Bat species Transect section Walk 1 Stop 1 Walk 2 Stop 2 Walk 3 Stop 3 Walk 4 Stop 4 Walk 5 Stop 5 Walk 6 Stop 6 Total Pipistrelle Pipistrelle Myotis sp Noctule Leisler's 5 5 Serotine Unidentified bat passes * Lesser Horseshoe Pipistrelle Pipistrelle Pipistrelle sp Myotis sp Serotine Unidentified bat passes Pipistrelle Pipistrelle Pipistrelle sp 1 1 Myotis sp Serotine Noctule Unidentified bat passes * 45 Pipistrelle Pipistrelle Myotis sp Serotine

39 Year Bat species Transect section Walk 1 Stop 1 Walk 2 Stop 2 Walk 3 Stop 3 Walk 4 Stop 4 Walk 5 Stop 5 Walk 6 Stop 6 Total 2015 Lesser Horseshoe Pipistrelle Pipistrelle Pipistrelle sp 2 2 Serotine 1 1 Myotis sp Barbastelle 1 1 Unidentified bat passes * The 2012 and 2014 surveys were completed in reverse starting at Stop 6 and finishing at Walk 1. No reappearance by the Leislers bat which caused excitement in 2011 but there was another Barbastelle recorded here. Are Barbastelles becoming commoner in the Blackdown Hills or is it easier to identify them in the sound analysis due to the experience of the analysers? There was a Lesser Horseshoe at Walk 3; the only time it has been recorded before along this transect in 2012, was along Walk 5. The total of Common Pipistrelle passes was the highest yet which suggests that they favour the central part of the transect between Walk 3 and Walk 5.

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41 Transect 11: Wambrook Year Bat species Transect section Walk 1 Stop 1 Walk 2 Stop 2 Walk 3 Stop 3 Walk 4 Stop 4 Walk 5 Stop 5 Walk 6 Stop 6 Total 2011 Lesser Horseshoe Pipistrelle Pipistrelle Myotis sp Noctule 1 1 Serotine Long-eared bat sp 3 3 Unidentified bat passes * Lesser Horseshoe Pipistrelle Pipistrelle Pipistrelle sp Myotis sp Unidentified bat passes Lesser Horseshoe Pipistrelle Pipistrelle 1 1 Myotis sp Serotine 1 1 Leislers 1 1 Unidentified bat passes * Lesser Horseshoe Pipistrelle Pipistrelle Pipistrelle sp Myotis sp Serotine 4 4 Unidentified bat passes

42 Year Bat species Transect section Walk 1 Stop 1 Walk 2 Stop 2 Walk 3 Stop 3 Walk 4 Stop 4 Walk 5 Stop 5 Walk 6 Stop 6 Total 2015 Lesser Horseshoe Pipistrelle Pipistrelle Nathusius' Pipistrelle 1 1 Pipistrelle sp Serotine Myotis sp 1 1 Long-eared bat sp 1 1 Unidentified bat passes 1 1 * The 2012 and 2014 surveys were completed in reverse starting at Stop 6 and finishing at Walk 1. Lesser Horseshoes are regularly recorded on this route, but usually at or near Walk 6. This year, a pass was recorded along Walk 3 suggesting that they are foraging some way from the known maternity roost. The count of Common Pipistrelle passes was well over double the previous highest. They seem to be spread throughout the transect with a preponderance in the second part. That was also so in 2014, a normal year, so that may be a genuine preference for those sections not an artefact of the time at which the surveyors arrived there.

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44 Transect 12: White Staunton Year Bat species Transect section Walk 1 Stop 1 Walk 2 Stop 2 Walk 3 Stop 3 Walk 4 Stop 4 Walk 5 Stop 5 Walk 6 Stop 6 Total Pipistrelle Pipistrelle Myotis sp Noctule 2 2 Serotine Unidentified bat passes * 45 Pipistrelle Pipistrelle Pipistrelle sp 1 1 Myotis sp Serotine Unidentified bat passes Pipistrelle Pipistrelle Pipistrelle sp 4 4 Myotis sp Serotine Unidentified bat passes * 45 Pipistrelle Pipistrelle Pipistrelle sp Myotis sp Serotine Long-eared bat sp Unidentified bat passes 1 1

45 Year Bat species Transect section Walk 1 Stop 1 Walk 2 Stop 2 Walk 3 Stop 3 Walk 4 Stop 4 Walk 5 Stop 5 Walk 6 Stop 6 Total Pipistrelle Pipistrelle Not Pipistrelle sp surveyed Serotine 1 1 Myotis sp Long-eared bat sp 1 1 Unidentified bat passes * The 2012 and 2014 surveys were completed in reverse starting at Stop 6 and finishing at Walk 1. The surveyors had to abandon Walk 6 and Stop 6 because of livestock. Enough of the transect was surveyed to be able to note that 44 Common Pipistrelle passes was very low compared with 212 in Admittedly the final sections tend to be good but even so there is a difference here that needs another year to verify. The count of Soprano Pipistrelle passes was greater than previously recorded, collaborating the results at Dunkeswell.

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47 Transect 13: Broadhembury Year Bat species Transect section Walk 1 Stop 1 Walk 2 Stop 2 Walk 3 Stop 3 Walk 4 Stop 4 Walk 5 Stop 5 Walk 6 Stop 6 Total 2011 This transect was not undertaken in * 45 Pipistrelle Pipistrelle Pipistrelle sp Myotis sp Serotine 2 2 Unidentified bat passes Pipistrelle Pipistrelle 1 1 Myotis sp Serotine Unidentified bat passes * 45 Pipistrelle Pipistrelle Pipistrelle sp Myotis sp Serotine Unidentified bat passes Pipistrelle Pipistrelle Pipistrelle sp Serotine Noctule 2 2 Myotis sp 1 1 * The 2012 and 2014 surveys were completed in reverse starting at Stop 6 and finishing at Walk 1.

48 This transect also showed a low number of Common Pipistrelle passes at 96. In 2012 there were 447 and in 2014 there were 198. It may be worth considering, Is this a transect that delivers more passes in reverse years? Certainly a significant number of passes have been recorded in the first half of the transect and it is possible that the surveyors get to that part too early in normal years. Both Noctule and Serotine were recorded but only one Myotis bat pass.

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50 Transect 14: Upottery Year Bat species Transect section Walk 1 Stop 1 Walk 2 Stop 2 Walk 3 Stop 3 Walk 4 Stop 4 Walk 5 Stop 5 Walk 6 Stop 6 Total 2011 This transect was not undertaken in * 45 Pipistrelle Pipistrelle Pipistrelle sp Myotis sp Serotine Barbastelle 2 2 Long-eared bat sp 1 1 Unidentified bat passes Pipistrelle Pipistrelle Pipistrelle sp 1 1 Myotis sp 1 1 Serotine Unidentified bat passes * 45 Pipistrelle Pipistrelle Myotis sp Serotine 1 1 Barbastelle 1 1 Unidentified bat passes

51 Year Bat species Transect section Walk 1 Stop 1 Walk 2 Stop 2 Walk 3 Stop 3 Walk 4 Stop 4 Walk 5 Stop 5 Walk 6 Stop 6 Total Pipistrelle Pipistrelle Pipistrelle sp 2 2 Serotine 7 7 Myotis sp 3 3 Long-eared bat sp Barbastelle 3 3 Unidentified bat passes * The 2012 and 2014 surveys were completed in reverse starting at Stop 6 and finishing at Walk 1. This transect can be relied upon for Serotine and Barbastelle passes. There was a slight increase in Soprano Pipistrelle activity but nothing as dramatic as we found at Dunkeswell or Whitestaunton. Whilst only four years of data have been collected, it would appear that the total of Common Pipistrelle passes at 146 is more typical than either 2014 with 41, or 2012 with an extraordinary 560.

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53 Transect 15: Cotleigh Year Bat species Transect section Walk 1 Stop 1 Walk 2 Stop 2 Walk 3 Stop 3 Walk 4 Stop 4 Walk 5 Stop 5 Walk 6 Stop 6 Total 2011 This transect was not undertaken in * 45 Pipistrelle Pipistrelle 3 3 Myotis sp Serotine Pipistrelle Pipistrelle 1 1 Myotis sp Serotine 1 1 Unidentified bat passes * Lesser Horseshoe Pipistrelle Pipistrelle Pipistrelle sp Myotis sp Serotine Unidentified bat passes Lesser Horseshoe Pipistrelle Pipistrelle Serotine Myotis sp Unidentified bat passes * The 2012 and 2014 surveys were completed in reverse starting at Stop 6 and finishing at Walk 1. Lesser Horseshoe Bats were recorded here for the first time. Unlike the ones at Wambrook it is unknown where they roost near this transect and there may be a case for trying to track them down. The Common Pipistrelle pass count was the highest in four years at 214. The results for Soprano Pipistrelles were deeply inconsistent; 3 in 2012, only 1 in 2013, up to 83 in 2014 and now was clearly anomalous and it is worth noting that over half the passes that year were at one point, Stop 2. It may have been one or two particularly busy bats circling the recorder for five minutes over the mill pond and stream.

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55 Transect 16: Netherclay Year Bat species Transect section Walk 1 Stop 1 Walk 2 Stop 2 Walk 3 Stop 3 Walk 4 Stop 4 Walk 5 Stop 5 Walk 6 Stop 6 Total 2011 This transect was not undertaken in * 45 Pipistrelle Pipistrelle Myotis sp Noctule 1 1 Unidentified bat passes Pipistrelle Pipistrelle Myotis sp Serotine Noctule 1 1 Unidentified bat passes * 45 Pipistrelle Pipistrelle 1 1 Pipistrelle sp Myotis sp Serotine Noctule Unidentified bat passes Lesser Horseshoe Pipistrelle Pipistrelle Pipistrelle sp Myotis sp Long-eared bat sp Unidentified bat passes * The 2012 and 2014 surveys were completed in reverse starting at Stop 6 and finishing at Walk 1.

56 Lesser Horseshoe passes at Walk 3 and Stop 3 were new and for this reason interesting. Again it would be interesting to know where they may be roosting. Many more Pipistrelle passes with Common Pipistrelles up to 232 from 149 in 2012 and Soprano Pipistrelles to 57 from 11 when this transect was first walked. Conversely there were 147 Myotis bat passes in 2012 but only 7 to 15 since was clearly anomalous and that might be because of the misty, thundery weather.

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