INTRODUCTION. This project is part of the UK National Bat Monitoring Programme: The aim is to develop effective monitoring strategies for resident species of bats in the UK. The project will produce baseline monitoring data on numbers and distribution of selected species in a framework that will enable the analysis of possible causes of population change and the consequences of changing environmental conditions. The project has two full-time members of staff, a Project Coordinator - Dr. Allyson Walsh and and a Senior Field Officer - Dr. Colin Catto, based at the Bat Conservation Trust offices in London. Over five years the programme is concentrating on eight species of bat.

PROJECT STRATEGY In the five-year time scale available, the programme is concentrating on eight species of bat. Daubenton's bat, Myotis daubentonii. Natterer's bat, Myotis nattereri. Pipistrelle 45kHz, Pipistrellus pipistrellus . Pipistrelle 55kHz, Pipistrellus pygmaeus. Lesser horseshoe, Rhinolophus hipposidderos. Greater horseshoe, Rhinolophus ferrumequinum. Noctule, Nyctalus noctula. Serotine, Eptesicus serotinus. For each of these species at least two different monitoring methods will be investigated. The results from these studies will be used to determine the most appropriate strategy to apply for monitoring all of the UK species. For each of the study species. the programme will attempt to meet the following objectives:

1. Develop efficient monitoring methods. This will involve carrying out field trials of new methods and making adjustments to methods already in place. 2. Produce baseline monitoring data. This will involve carrying out UK-wide surveys for a particular species using one or more of the methods over a two year period where possible. Thus, a mixture of different species will be concentrated on in each year of the programme. In the case of hibernation counts, these will be carried out for all species over the whole five-year period. 3. Produce improved distribution maps. By collecting monitoring data, a by-product will be improving the knowledge of the distribution of each species.

PROJECT METHODS The main counting methods that form the basis of the monitoring programme are: Maternity colony counts Hibernation site counts Field transect/spot counts using bat detectors This project covers the first year of the NBMP and was carried out in 1997. All the roosts surveyed come under the general heading of Summer Roosts. These include three different types, mating, nursery and transitory. Five species of bats were surveyed. Daubentons, Myotis daubentonii, Noctule, Nyctalus noctula, Serotine, Eptesicus serotinus and Pipistrelle 45, Pipistrellus pipistrellus and Pipistrelle 55, Pipistrellus pygmaeus. The survey areas are allocated by the Bat Conservation Trust and the same species of bats are surveyed at the same time across the UK. This is done even if it is unlikely that all of them will be found. The roost counts are done at those already known to exist and counted.

BATS AND THE LAW.

Before details of the projects are given it is important to point out that they were done under the constraints of legislation that is devised to protect bats and there habitats. No roosts were entered as this is illegal without a license from the Statutory Nature Conservation Organisation, in this case English Nature. Licences are only issued after being successfully taught by a qualified trainer. All bats are protected by section 9 and are listed under Schedule 5 of the Wildlife and Countryside Act 1981. These are those considered at risk or endangered. They are also included in Schedule 2 of the Conservation ( Natural Habitats, etc. ) Regulations 1994. The Act and Regulations include provisions making it illegal to: *intentionally or deliberately kill, injure or capture ( take ) bats. * deliberately disturb bats ( whether in a roost or not ). * damage, destroy or obstruct access to bat roosts. A bat roost is interpreted as any structure or place which is used for shelter or protection whether or not bats are present at the time.

The UK is also party to the Agreement on the Conservation of Bats in Europe and are obliged to protect sites which are important for bats, and to identify and protect important feeding areas for bats from damage or disturbance. Appendix 3 of the Bern Convention and Annex 4 of the EC Habitats Directive also give them species and habitat protection.

All the species surveyed are listed as vulnerable in the Red Data Book and are listed ( Long List ) as a globally threatened/declining species according to the Biodiversity ( UK ) Steering Group Report in 1995

DESCRIPTION OF PENWITH.

Penwith is an almost treeless, exposed, ancient landscape that incorporates the Lands End peninsula in Cornwall. It is a product of the underlying granite, severe exposure to the Atlantic elements and a long agricultural history. The area is characterised by tracts of heathland, many of which are unenclosed and small, irregularly shaped fields bounded by Cornish hedges. Some of these fields are over two thousand years old. Narrow streams in steep valleys drain the peninsula into the ocean that almost surrounds the entire area. The remains of derelict tin mines are common in the area. Penwith supports a high proportion of lowland heath and some maritime heath is found on the coast. Penzance and St. Ives are the only major urban areas.

METHOD. PROJECT ONE. Colony counts Species: Pipistrelle 45, pipistrelle 55 and serotine. Dates: 8 June - 23 June. Two pipistrelle colonies were visited one hour before dusk. ( Bat Conservation Trust. 1997a ). The weather conditions and temperature were noted. Counts on two evenings for each colony were carried out using a bat detector and tally counter. The detector was turned up to 60 kHz and down to 40 kHz repeatedly to find 45 and 55 pipistrelles. Counting stopped when no bats had emerged from the roost for fifteen minutes. The results of the count were recorded as well as that of a habitat survey carried out in the locality of the roosts. First count between 8 June - 15 June and the second between 16 June - 23 June. No serotine roosts were counted as none are known in the survey area.

PROJECT TWO. National Daubenton's field survey. Species: Daubenton's bat Dates: Between 26 July - 14 August The Bat Conservation Trust asked for six stretches of river to be surveyed due to the interesting location of the survey, i.e. West Cornwall. The survey involved walking a 1 km route along each river, ( Bat Conservation Trust 1997c ) recording Daubenton's bat activity at 10 points along the route. This was done forty minutes after sunset when the bats begin to emerge. A starting point was decided upon and marked on the map. The ten points were chosen by pacing one hundred steps along the riverbank and recording the position on the map and then repeating, until ten points in a one kilometre stretch had been reached. A bat detector was used, set at 35 kHz, at each point for four minutes and a high powered torch used to locate bats flying over the river. This was done twice for each stretch of river. Also each river had to be visited during daylight to establish the route to be walked and habitat forms filled in. The habitat maps were used to help pinpoint the survey points so that future surveyors could relocate them, eg. point next to bridge. Only rivers of more than one metre in width were surveyed.

PROJECT THREE. Noctule, serotine and pipistrelle ( 45 and 55 ) pilot survey. Dates: August - September. This pilot project aimed to find ways of minimising the effort in surveying. ( Bat Conservation Trust 1997d ). Data on four species was recorded, noctule, serotine, pipistrelle 45 and pipistrelle 55 on the same evening. A 3km. triangular transect was walked within a 1km. square. Bats were recorded at nine points on two evenings. Two minutes surveying with a bat detector at each point on the first night and three minutes for the second. This survey was then compared with another pilot scheme involving six points instead of nine. Each point was surveyed with a bat detector for three minutes on the first night and four on the second. The survey area and the points to be surveyed from were chosen by the Bat Conservation Trust. The surveys started ten minutes after sunset. The best time to find all four species. The time, temperature and weather conditions were recorded before the walks started. The route was started with the detector set at 25 kHz to find noctules and serotines in flight. Any other bat species was ignored, only the noctules and serotines were recorded at this time. At each point the bat detector was retuned to 50 kHz to find pipistrelles. The detector was turned up to 60 kHz and down to 40 kHz repeatedly to find 45 and 55 pipistrelles. Any noctules or serotines found were marked on ñ Walk one ñ of the survey sheet and any pipistrelles marked at ñ Spot oneî. The survey then continued after the pipistrelles had been searched for the allotted time. This then became ñ Walk two ñ and then ñ Spot two ñ on the recording sheet and continued in this way until the survey was finished. NOTES: 1. The surveys were either carried out by myself or with my brother, David Smith. His presence was needed for Health and Safety reasons stipulated by the Bat Conservation Trust. Surveying at night can obviously be dangerous, especially on the Penwith moors that are littered with uncapped mine shaft 2. Surveys were not carried out in temperatures of below 5 Celsius, heavy rain or strong winds as bats seldom emerge from roosts under these conditions.

PROJECT FOUR. Super survey. Species: All. Dates: April -August. Every inhabited building within a 4km. square had a letter delivered to the occupants asking if they had a bat roost. ( Bat Conservation Trust. 1997b ). If they had, they sent a prepaid card to the Bat Conservation Trust giving details. The 4km. square incorporated SW 38 34, SW 38 35, SW 39 34 and SW 39 35. All potential roost sites in a 1km square within the 4km. square were checked personally for the presence of bat colonies. This 1km. square was SW 38 34. This involved a variety of survey techniques including day surveys of trees,bridges, empty buildings and barns. Also night walks with detectors. The tree survey was carried out by looking for: * obvious holes, cavities and splits that may contain a roost. * staining around a hole caused by the natural oils in a bats fur. * dark staining on the tree below a hole caused by bat droppings. * tiny scratch marks around the hole made by bat claws. * noise coming from a hole - especially on a hot day or at dusk. A bat detector set at 25kHz is the best way of hearing vocal bats in day roosts. * droppings below a hole. They look similar to rodent droppings but crumble to a powder of insect parts when touched.

Bridges were also checked during the day time using a bat detector to locate vocal bats in crevices. Bridges crossing waterways were checked as well as those carrying water under roads.

Uninhabited buildings were checked mainly during the day time. A few promising sites were also rechecked during the evening at sunset.

Evening bat walks were carried out in the 1km square using the bat detector scanning between 25 to 55 kHz ensuring that all species were covered. Each potential roost site was visited for a couple of minutes and each walk lasted about 20 minutes. Each circuit was started at sunset and repeated twice so that each potential roost site was visited twice and the time surveying was approximately 40 minutes.

EQUIPMENT USED FOR THE SURVEY. BAT DETECTOR. As echolocation is known to be employed by all the bats being surveyed2 it was possible to use a bat detector to locate and identify bats. In this case Bat Box III was used. Echolocation is a physiological process for locating distant or invisible objects (such as prey) by means of sound waves reflected back to the emitter ( a bat) by the objects. Echolocation is used for orientation, obstacle avoidance, food procurement, and social interactions. Echolocation pulses consist of short bursts of sound at frequencies from about 30 kHz to about 120 kHz. The pulses are repeated at varying rates. In a single individual, depending upon the situation, beginning at about one per second. The rate may reach several hundred per second e.g., in a bat close to its target. The Batbox III is a tunable heterodyne receiver with two piezoelectric transducers to extend the available frequency range. They are most sensitive at around 20-50 kHz, and are light, portable and robust. Tuning is via a dial with frequency markings backlit by an LED. A socket for headphones and tape is included. A walkman was used to record bat calls so that they could be analysed later by comparing them with an ID tape. Heterodyning - the input signal (Finput) from the ultrasound microphone is mixed with the output from an oscillator whose frequency (Fosc) is controlled by the tuning dial. This produces a signal with two frequencies (Finput + Fosc) and (Finput - Fosc). This signal is fed into an intermediate (IF) amplifier which has a limited bandwidth (typically only ±5 kHz) so that only the (higher) (Finput + Fosc) signal is passed. This signal is then mixed with a second, fixed frequency, oscillator to bring the output from the IF amplifier down to the human audible range (the higher frequency component being rejected). The advantages of a heterodyne receiver (technically a superheterodyne receiver in this case since it uses two mixer circuits), is that all amplifier stages are well separated in frequency , so high amplifier gains can be used. Also, the limited bandwidth of the IF amplifier means that noise is limited in bandwidth too, giving a good signal/noise ratio. Since you can tune the detector, it is possible to listen to the bats echolocation call and determine the upper and lower frequency limits, which can aid in identification. ( See ïdifficultiesÍ on page 27 ).

TALLY COUNTER. These are useful when a large roost is encountered and a rapid count has to be made. It is held in the hand and a button pressed everytime a new bat is seen. The counter reading gives the number of bats.

TORCH. A high power torch was used to scan the surface of rivers to find Daubentons bats during that survey. For the other surveys a torch would have scared the bats unnecessarily and affected the survey results e.g. stopping bats leaving roosts so that they arenÍt counted. A Mini Maglite AA torch was carried at all times in case of emergencies.

THERMOMETER. This was used to measure the temperature at the start of each walk

A first aid kit, whistle, map, compass, survival blanket and food were carried on all occasions in case of emergencies. RESULTS. PROJECT ONE. Pipistrelle colony counts. The first roost checked was at Bosavern Barn, St. Just ( SW 364 306 ) on the 12th and 19th of June where two bats were seen on both occasions. The second roost at Drift Barn, Drift ( SW 438 285 ), was checked on 10th and 18th June and no bats were found. Although outside the survey dates 82 pipistrelles were recorded on August 5th at the Coach House, Trevaylor ( SW 468 325 ). This is a previously unrecorded roost that was found whilst carrying out the Daubenton survey at the nearby Trevaylor Stream. A roost of three bats was also found outside the survey dates at Lower Keigwin Farm ( SW 396 347 ) during the Super Survey ( see page 17 ). This means that only one summer roost containing two bats were found. The one at Trevaylor would probably be a maternity roost and contain females and young. The maternity roosts are formed by females when they leave summer roosts to give birth to the young that they conceived the previous year. All the pipistrelles were Pipistrellus pipistrellus, no Pipistrellus pygmaeus were found. An example of the results are on the following pages. The other result sheets for the pipistrelle survey are to be found in Appendix One.

PROJECT TWO. Daubentons survey. No Daubentons bats were found on any of the surveyed rivers. These were the: Lamorna Stream ( SW 448 245 ) on the 29th and 30th July. Penberth River ( SW 403 227 ) on the 5th and 14th of August. Red River ( SW 501 351 ) on the 2nd and 15th of August. Trevaylor Stream ( SW 466 330 ) on the 1st and 13th of August. Tregeseal/Kenidjack Stream ( SW 370 318 ) on the 27th July and the 9th of August. Hayle River ( SW 565 325 ) on the 28th July and the 8th August. A previously unknown roost was found at a water tower at Drift Reservoir ( SW 433 290 ) on August 8th. Although not part of the survey it is of significant importance. Although no bats were found on rivers this discovery confirms the presence of the species in the area. An example of the results are on the following pages. The other result sheets for the survey are to be found in Appendix Two. NOTES: 1. All grid references are taken half way between the stretch of river/stream surveyed. 2. The Lamorna stream was difficult to survey as it ran through gardens - the owners of which couldnÍt be contacted to allow access. This meant that the bat detector had to be carried out from the nearby road.

PROJECT THREE. Noctule, serotine and pipistrelle pilot survey. The 9 spot counts for 2 minutes each were carried out on September 5th 1997 in 1 km. square SW 38 33. No bats were found. The 9 spot counts for 3 minutes each were carried out on September 6th 1997 in 1 km. square SW 38 33. One unknown bat was seen and one pipistrelle 45. The 6 spot counts for 3 minutes each were carried out on September 5th 1997 in 1 km. square SW 38 34. No bats were found. The 6 spot counts for 4 minutes each were carried out on September 6th 1997 in 1 km. square SW 38 34. One noctule was seen and four pipistrelle 45s. An example of the survey results are on the following pages. The other result sheets for the pilot survey are to be found in Appendix Three. The maps were provided by the Bat Conservation Trust as enlargements from 1:25 000 O.S. maps. The new scale is 8cm = 1km.

PROJECT FOUR. Super Survey. In spite of continuous searching over a three month period only one new roost site in the 4km square was found. This consisted of three pipistrel

DISCUSSION. PROJECT ONE. Colony counts Species: Pipistrelle. The species reliance on buildings makes it vulnerable to renovation work, exclusion and toxic remedial timber treatment chemicals. This was obviously the case at Drift Barn where an old derelict barn had been converted into a modern house. The new roof had no access for bats and the renovation work had probably forced the colony to move. Before restoration the colony size was counted as 165 on June 11th 1987. The Bosavern Barn colony was also greatly reduced from previous counts of a decade ago when 180 bats were present on June 25th 1987. Now only two are present. When the last count was done the barn had already been converted so the reason for the reduction in number is not so obvious here. The access to the roost is unblocked and the owners are sympathetic to bats. The garden is well wooded and close to water. The previous pipistrelle counts were carried out by John Page who used to be the bat recorder for Cornwall. Unfortunately, a breakdown by County and parts of Counties is not yet available. Only pipistrelle 45, Pipistrellus pipistrellus, were found.

The number of Pipistrellus pipistrellus found is small when compared with other parts of the UK that were surveyed at the same time. The figures are from the Bat Conservation Trust. The South West, as a whole, had a mean colony size of 132.9 and a maximum colony size of 744 out of 27 colonies counted. These figures show that the South West of England has 8.5% of pipistrelle 45, Pipistrellus pipistrellus.

PROJECT TWO. National Daubenton's field survey. There are several possible reasons why there are no Daubentons bats on the rivers surveyed. The rivers are too narrow for the bats to forage as they catch insects above and on rivers and need room to manoeuvre. They need a river of about three metres wide to be able to scoop up an insect off the water, circle around and fly off. The rivers surveyed were all one - two metres wide. Either the channel was naturally narrow or as in the case of some i.e. Tregeseal and Kenidjack have become choked with Japanese Knotweed, Polygonum cuspidatum. The National Trust who own part of the site that the Kenidjack flows through are trying to control it by spraying and therefore restore the river to its wider width. Also, the presence of heavy metals in the waterways resulting from past mining activity may be affecting the bats or their food supply in some way. However Daubenton's bat seems to be increasing in some parts of Penwith. This may, in part, be associated with the increasing numbers of artificial water bodies, including gravel pits, reservoirs and flooded quarries. The new roost found at Drift Reservoir proves this. The South West of England, as a whole, had a good number of Daubentons reported on rivers during the survey. A mean number of 73.1 passes recorded during the 40 minutes of surveying at each of 21 sites. This compares favourably with other areas of the UK. These are detailed on the next page. Unfortunately, a more detailed breakdown is not yet available. When these are it will be easier to compare the river types with the number of bats found. A comparison between the rivers of Devon and Cornwall would be especially interesting as the bats are far more common in Devon than they are in Cornwall. A survey of other large bodies of water to find Daubentons would prove to be of interest in Penwith. A lot of mine workings have become flooded and are now colonised by vegetation and are home to many invertebrates. These areas could prove to be of major importance to the distribution and survival of this bat in Penwith. It was noted that repointing work was taking place on some of the stone constructed bridges that were checked for roosts. This would have scared any bats away.

PROJECT THREE. Noctule, serotine, pipistrelle 45 and 55 pilot survey. The results were compared with the other thirteen people around the UK that had carried out the pilot survey. Unfortunately, access to other peoples results is impossible at the moment as it is still being analysed. Overall, the Bat Conservation Trust decided that both methods provided exactly the same results. In Penwith it showed the absence of bats from the West Penwith moors and that they were more likely to be encountered over agricultural land used by livestock.

PROJECT FOUR. Super survey. The survey took many hours to complete to find that there are few bats in the area. Trees were checked, old mine shafts, derelict buildings and the local church,. All to no avail. The mail drop provided only one new roost site. The one at Lower Keigwin Farm ( SW 396 347 ) where three pipistrelle 45s were found on August 3rd 1997 this was discovered to late to be included in the pipistrelle summer roost survey. The people that reported bats in Pendeen seemed to be seeing the same two pipistrelles. This shows the importance of properly conducted surveys. If anecdotal evidence was to be relied on the village of Pendeen would be thought of as being the site of many bats. The tree survey proved to be discouraging. Bats prefer native trees such as ash, Fraxinus exelsior, and oak, Quercus spp: to roost in and to supply them with tree dwelling insects. The area surveyed is virtually treeless except for what people plant in their gardens. This is usually sycamore, Acer pseudoplatanus, or Monterey pine, Pinus radiata, as these are the hardiest species to survive the wind and the rain that continually lash the area. Monterey pines are also resilient to the heavy metals found in the soil as a result of the tin mining industry. This survey will not be continuing but the new roost will be checked again this year, during June 1998 as part of the summer roost survey.. This time at sunrise as it is thought that the higher light levels will make it easier to count the returning bats. Future surveys should also include the more urban areas of Penwith.

Difficulties encountered during the survey. As the weather was bad during the survey period this limited the days that surveying could be done. A complete lack of published scientific research on bats in Penwith means that proper comparisons between species numbers over a period of time is impossible. Neither the Bat Conservation Trust, Cornwall Wildlife Trust, English Nature or the Cornish Biological Records Unit could provide details of any research papers. The only recent figures available are those for the pipistrelle roosts surveyed. These are the personal records of John Page who used to be the bat recorder for Cornwall until his stroke several years ago. His records, although unpublished, have been treated as being accurate. The Natural History of Cornwall, which is one of two books often used as a baseline for research, makes no mention of bats anywhere in Cornwall. Even though written over two centuries ago by William Borlase, it is still treated as a reliable account of other species. The other book often quoted from is the Victoria County Guide for Cornwall published in 1906. This makes no mention of bats specifically in Penwith. However, it does say that the pipistrelle is common in all of Cornwall. Another difficulty was with the bat detector. The disadvantage with Bat Box III is that only a limited bandwidth output is produced which cannot be used for spectrographic analysis. In addition, by tuning to one frequency bats which are calling at a different frequency may be missed Problems were found between separating pipistrelles and Daubentons. Pipistrelles can be heard at 35 kHz too. Although pipistrelles have a CF ( constant frequency ) tail at 45 kHz, there are frequencies either side of this, and these frequencies can extend quite low. The problem is compounded by two other factors: first is that pipistrelles drop the CF tail when feeding close to clutter or water surfaces, making the typical change in note around 45 kHz more difficult to hear and making confusion with Daubentons worse, and the fact that bat detectors have a certain bandwidth around which they detect sounds. The Batbox III has a bandwidth in the intermediate frequency amplifier of about 10 kHz, meaning that even if the detector is tuned to 45 kHz, it is still sensitive to frequencies between 40 and 50 kHz, similarly, if it is tuned to 35 kHz, it will still be sensitive to between 30 and 40 kHz. With practice and using an identification tape the problem was solved as Daubentons and pipistrelles sound different on the detector. Even when pipistrelles drop their CF tails, they sound less 'machine gun like' than Daubentons. Ironically, the vast amount of protection given bats under the law ( see page 4 ) has led to a lack of knowledge about bats. Knowledge that may be of use to the species survival. An example being, as it is illegal to enter a roost without a license, proper counts cannot be made by unqualified people. In Cornwall if someone wants to get a license they have to be trained by someone in Devon as no - one is able to do it locally. This is one of the main reasons for the lack of research into Cornish bats.

Species Descriptions. A description of each bat surveyed and its ecology has been included. This is because it is necessary for surveyors to understand the lifestyle of each species and how it affects the choice of habitat in which they live. Care has been taken to use references that mostly refer to bats found in Southern England as bat ecology can vary within the species depending on the country of origin. Bats are members of the mammalian order ,Chiroptera. They are the only mammals capable of true flight, that is, flight powered by muscular movement as distinct from gliding. The wing is a double membrane of skin stretched between the enormously elongated bones of four fingers and extending along the body from the forelimbs to the hind limbs and from there to the tail. The thumb is small, clawed, and free from the membrane. The hind limbs are small and may be rotated in such a way that the knees bend backward rather than forward, as in other mammals; this is presumably an adaptation for takeoff and flight. Bats at rest hang head down, grasping a twig or crevice with their clawed feet; they take off into flight from this position. All bats in the British Isles are nocturnal. They rely primarily on their highly developed hearing, using echolocation to avoid collisions and to capture insects in flight. Insects are the diet of all British bats. Most of the insect species eaten are those associated with mature native trees. The bat emits high-pitched sounds (up to 100 kHz depending on the species) that echo from objects it encounters; the echo provides the bat with information about the size, shape, and distance of the object. Natural predators of bats include owls. Roosts and hibernacula are attacked by rats and cats.

Daubenton's bat. Myotis daubentonii.

Description. Head and body length 45 - 55mm. Forearm length34 - 41mm. Wingspan 240 - 275mm. Weight 7 - 12g. Fly at about 25kph(15mph).

They have brown fur with a pale underneath. The pinkish face has a bare patch around the eyes. A medium-sized species having a steady flight that is often seen flying a few centimetres over rivers, streams and other freshwater habitats. They catch insects from close to the water surface using their large feet as a gaff. They have sometimes been seen taking prey directly from the water surface, using their tail membrane as a scoop. Typical food consists of small flies,midges,caddis flies and Mayflies Daubenton's bats usually feed within about 6km of the roost, but have been recorded following canals for up to 10km. It is thought that they need to drink more frequently than some other species. They often travel across land and occasionally feed away from water. One study in England (Swift and Racey, 1983) documented the following dietary components (based on fecal analyses): 57.2% Diptera, 36.4% Trichoptera, 2.1% Ephemeroptera, 1.9% Lepidoptera, and 0.6% other insects. This species feeds opportunistically on large insect swarms which rise from the water surface at night. It may take prey with as small as a 5 mm wingspan, and also eats large and slow insects (like Trichoptera and Ephemeroptera), but does not eat many large and fast-flying insects (such as moths and beetles). In some areas they has been documented eating ostracods and small fish. Parasites associated with freshwater gastropods have also been found in its faeces. Jones and Rayner (1988); Kalko and Schnitzler (1989); Miller and Degn (1981); Rydell et al. (1996) They mate during Autumn and throughout the winter. The maternity colonies consisting almost entirely of adult females are established during late spring with one young being born between the end of June to early July. They are weaned at six weeks and can live up to 22 years. Males or non-breeding females may form their own communal roosts during the summer, but sometimes join maternity colonies. In England the majority of known summer colonies are in humid, more or less underground sites near water. These may be tunnels or bridges over canals and rivers; or in caves, mines and cellars. They are only occasionally found in buildings, usually old stone buildings. Tree holes are probably much more widely used than the recorded evidence suggests and they have also bred in bat boxes. Summer colonies are often quite noisy throughout the day, especially at sites where they are close to human activity. A variety of temporary night roosts are used, often in trees or tunnels close to their feeding sites. Daubenton's bats have been found clustering during summer in large colonies with pipistrelles, noctule, Natterer's and brown long-eared bats. When occupying a multi-species roost Daubentons often partitions resources in and around the roost. The individuals of each species congregate together in a separate portion of the roost. They often leave the roost to hunt between one and two hours after sunset, and returns just before sunrise. It never leaves or enters the roost at the same time as another species it is roosting with. In addition, it does not seem to time its feeding with peaks in insect activity. In fact, it often emerges later than other species which have virtually identical diets. It has been suggested that the feeding time represents a compromise between levels of insect activity (which are generally greater around sunset) and light (with greater light levels increasing the possibility of predation by diurnal raptors). Also they never roost with other species that hunt over water. When hunting, members of this species may emit calls to inform conspecifics of the presence of large food sources (such as swarms). Under other circumstances, bats have been seen chasing other bats away from food sources.

Ultra-sound. Daubenton's bat ultrasound calls range from 35-85 kHz and peak at 45 - 50 kHz. On a bat detector the calls are a machine-gun like series of regular clicks for bursts of 5 to 10 seconds.

Daubenton's bat. Pipistrelle 45 & pipistrelle 55: Pipistrellus pipistrellus and Pipistrellus pygmaeus. Description. Head and body length 35 - 45mm. Forearm length 28 -35mm. Wingspan 190 - 250mm. Weight 3 - 8g. They are coloured a medium to dark brown.

The separation of the common pipistrelle into 2 species is a recent occurrence and has been confirmed by DNA analysis. A few people claim to be able to identify the two species in the hand but usually it is made on the peak frequency of the echolocation calls. 45 pipistrelles are identified by the loudest part of the call being heard between 42-47 kHz, whereas 55 type pipistrelles are identifies by the loudest part of the call being heard between 52-60 kHz. The pipistrelle is Britain's smallest and commonest species and is found throughout the UK and is also abundant and widespread in the rest of Europe. Pipistrelles fly at about head height with irregular twists and dives. A single pipistrelle may consume up to 3000 insects in a night which are caught and eaten in flight. Maternity colonies are established between May and September after mating occurs during autumn at well established mating roosts. Buildings and trees are used, a colony can consist of 25 - lower 100s (up to 1000+) bats. They are almost exclusively females. One young, sometimes two, are born early June to mid - July. They are weaned at six weeks and live up to 16 years. Most colonies start to disperse soon after the young are weaned. They search for food over water, marshes,open woodland, woodland edge, farmland, along hedgerows, suburban gardens and urban areas Food consists of mosquitoes, midges, small moths and lacewings Buildings are the most favoured roost sites and more than half of known roosts are in buildings less than 30 years old. Pipistrelles prefer to roost in very confined spaces around the outside of the building, typical sites being behind hanging tiles, weather boarding, soffit and barge or eaves boarding, between roofing felt and roof tiles or in cavity walls. Pipistrelles rarely enter roof spaces except in the more stable, well established large colonies found particularly in older buildings. Pipistrelles are also found roosting in treeholes and crevices, behind ivy and in bat boxes. They can be noisy as the time for emergence approaches. They usually start to emerge from the roost about 20 minutes after sunset. Large numbers of pipistrelles circling around the roost entrance at dawn make a spectacular sight.

Ultra-sound. The calls range from 40 - 60 kHz and peak at about 50 kHz. On a bat detector a series of clicks turns into "wetter" slaps towards the bottom of the frequency range. However, their "social" call is emitted at between 20 - 30 kHz and is heard as a "chonk".

Noctule bat. Nyctalus noctula Description. Head and body length 60 - 82 mm. Forearm length 48 -58 mm. Wingspan 320 - 400 mm. Weight 18 - 40g. Noctules can fly at 50kph (30mph). Adults are golden brown, in colour. Juveniles and some females are dull chocolate brown. They have broad brown ears and a distinctive mushroom shaped tragus. The noctule bat is one of the largest British species and is usually the first bat to appear in the evening, sometimes even before sunset. Noctule bats are primarily tree dwellers and live mainly in rot holes and woodpecker holes. They occur rarely in buildings, but will use a wide variety including modern houses. Within buildings they roost in gaps in large ridge tiles, behind hanging tiles, between the ceiling and floor boarding, above large soffits, between the tiles and ceiling of a converted attic. Sometimes they roost in the lining of tall disused industrial chimneys and other hollow walls including cavities in bridges. They feed over deciduous woodland, parkland, pasture, water and at the edge of forests. They forage mainly at dusk for up to two hours and for about half an hour at dawn

Vincent Smith

vincent.smith@tesco.net
Cornwall
United Kingdom