Natural England works for people, places and nature to conserve and enhance biodiversity, landscapes and wildlife in rural, urban, coastal and marine areas. We conserve and enhance the natural environment for its intrinsic value, the wellbeing and enjoyment of people, and the economic prosperity it brings. Focus on : www.naturalengland.org.uk discovering their lifestyle © Natural England 2007 and habitats Printed on Evolution Satin, 75% recycled post-consumer waste paper, elemental chlorine free

ISBN 978-1-84754-019-5 Catalogue code NE23

Written by Tony Mitchell-Jones. Designed and printed by statusdesign.co.uk Front cover image: Brown long-eared in flight. Stephen Dalton/NHPA. www.naturalengland.org.uk Focus on bats This leaflet is designed to answer many common questions people have about bats. If, after reading it, you’d like to learn more about bats and their conservation, get in touch with your local bat group or the Bat Conservation Trust (see Contacts, page 22).

In England, all bats and their roosts are protected by law. If you wish to do anything that might disturb bats or affect their roosts you should seek advice from Natural England first. See Bats and the law, page 21.

What’s special about bats? east Asia, which is little bigger than a Bats are the only true flying . large bumblebee. In Britain, there are Like us, they are warm-blooded, give only 17 bat species, all of which are birth and suckle their young. They are small and eat insects. also long-lived, intelligent and have a complex social life. Although they’re In many parts of the world, including often called flying mice, they’re not Britain, bats have declined drastically closely related to mice but form a in recent years. Although we don’t special group of their own called the have much historical information Chiroptera (from the Greek words on their numbers, it’s clear that our ‘chiro’ meaning ‘hand, and ‘ptera’ bats are under threat and many meaning ‘wing’). Worldwide, there are species are now much less common over 1,000 bat species, ranging from than they were. One species, the the tropical flying foxes, with a wing- greater mouse-eared bat, is more span of almost two metres (six feet), or less extinct in Britain and several down to the hog-nosed bat of south- others are very rare. Group of young brown long-eared bats. Melvin Grey/NHPA Brown long-eared bat. F. Greenaway Brown long-eared bat. F. 2 3 Bat biology flying, bats produce a stream of high-pitched calls. By listening to the Wings echoes of these calls, they can Bats’ wings are made out of a soft, produce a highly accurate ‘sound elastic membrane of skin stretched picture’ of their surroundings. over their arms and legs. Bats have Most of these echo-location calls are the same types of bones in their arms too high pitched for us to hear, but as humans, but their hand bones are relatively inexpensive electronic bat much longer. As their arms and legs detectors are now available that can help to support the wings, bats find pick them up and turn them into it easiest to hang upside down when sounds audible to the human ear. they’re roosting. Some species wrap their wings around themselves like a Feeding cloak when they’re asleep. Worldwide, bats eat many things. Some are vegetarian, eating only Sonar fruit or even nectar; while others hunt Although bats are far from blind, fish, frogs, mice, or even other bats. their eyes aren’t much use when However, in countries with cool hunting insects in the dark. To help climates, such as Britain, bats eat them hunt, bats have developed a only insects, which they catch in highly sophisticated echo-location flight or pick off water, the ground or system that allows them to catch tiny foliage. Some bats specialise in insects and avoid obstacles, even in catching large insects such as beetles complete darkness. When they’re or moths, but others eat very small insects, such as gnats, midges and Greater horseshoe bat, one of our largest species. Stephen Dalton/NHPA mosquitoes, catching thousands of them every night. Bats gather to feed wherever there are lots of insects, so the best places to find them include areas of traditional pasture, woodland, marshes, ponds and slow-moving rivers.

Hibernation There aren’t many insects around during the winter, so insectivorous like bats have to change their ways in the colder months. Birds

Bechstein’s bat. F. Greenaway bat. F. Bechstein’s change their diet or migrate south to 4 5 about. Even on very cold nights, bats may be seen on the wing as they move to more sheltered roosts. Flying in winter uses up energy which the bats can’t easily replace. Hibernating bats should not, therefore, be disturbed as this might affect their chances of surviving into the spring. Bats have much better control over their body temperature than other hibernating animals, such as hedgehogs or dormice. Even during the summer they can conserve energy by letting their body temperature drop when they’re in their roosts. In this way, bats can sleep through periods of bad weather and Natterer’s bat in hibernation. when other small animals might The bats are so cold that condensation forms on starve to death. their fur. Tony Mitchell-Jones/Natural England

warmer climates, but our bats have Breeding perfected a different technique – Our bats have a unique and

they hibernate. During the autumn, fascinating way of fitting their Pipistrelle bat in flight. Hugh Clark/FLPA bats put on weight and then, as the breeding cycle in with hibernation. How do bats live? weather gets colder, they let their They mate during the autumn or Lifespan body temperature drop to close to winter, but the female stores the Compared with other small Most bats form social colonies for at that of their surroundings. They also sperm alive in her body and becomes mammals such as shrews and mice, least part of the year. Female bats slow their heart rate to only a few pregnant the following spring. bats are amazingly long-lived. They gather together in maternity colonies beats per minute. This helps their fat Pregnancy lasts for six to nine weeks can live for over 25 years in the wild – for a few weeks during the summer to reserves last as long as possible. In and can vary in length depending on a remarkable feat for an give birth and rear their babies (a this state, bats can’t wake up quickly the weather. Usually, only one baby is weighing less than 10 grams! Part of female bat will usually only give birth to move out of danger, so they born each year. This is looked after the reason for this long life-span to a single baby each year). Once the choose undisturbed places to carefully and suckled for between might be the fact that they can babies are independent, the colony hibernate in. four and five weeks until it is old conserve energy by hibernating. breaks up and the bats generally enough to fly out and hunt for itself. They also breed slowly, producing move to other roosts. Bats from a Surprisingly, bats don’t sleep right Bats don’t bring food back to the one baby a year, or every other year. wide area may gather together to through the winter but may wake up roost to feed their young, so the baby In contrast, a wild mouse will live form these colonies, so any disaster and go out to feed and drink on mild lives only on its mother’s milk until it less than two years, producing up at a summer breeding site can wipe evenings when some insects are is old enough to fly. to 100 young in that time. out all the local females. 6 7 During the winter, bats aren’t often • Hollow or damaged trees. Bats in buildings the largest colony ever found seen, but clusters of hibernating bats Bats roost in cracks, cavities or contained well over 1,000. Bats are occasionally found in hollow under loose bark throughout With the clearing of Britain’s choose their roosts quite carefully. walls when buildings are being the year. woodland, bats have had to adapt to During the summer, they look for demolished, and sometimes turn living in buildings. Many species sites which are warmed by the sun, up in buildings such as churches. Each species has its own preferred now rely heavily on buildings for so they are most often found on the Underground places such as caves, types of roost. Some are almost roosting, so their conservation south or west sides of buildings. mines and cellars can house always found in buildings, others depends very much on our tolerance Most species prefer to roost in quite important numbers of bats during rely on buildings during the summer and goodwill. Bats are usually small spaces and they’re not usually the winter and a few special sites and caves or mines during the temporary seasonal visitors to found in open, draughty areas. are used by several hundred bats winter, whilst others prefer trees. houses, a little like house martins. for hibernation. Bats are creatures of habit and tend They normally form maternity Pipistrelles, our smallest and most to return to the same sites at the colonies during May or June and common species, are almost Where do bats live? same time year after year. For this then leave during July or August always found roosting in the eaves reason, roosts are legally protected once the young bats are of houses, or under hanging tiles or During the summer, bats fly out to even if bats don’t seem to be living independent. The colonies tend to wooden cladding on the outside of feed on insects at night and then there when you look. be most obvious during early July, buildings, rather than in the loft. spend the day in their roosts. In when the young are starting to fly, Pipistrelles colonise new buildings winter, they hibernate for long However, bats rarely use the same but soon after this the adults will quite readily, so many colonies are periods in sheltered places. roosting place all year round as start to leave, followed by the young. in houses built since the 1960s. Although bats can be found in all they need different conditions for Of course, different species have By contrast, brown long-eared bats, sorts of places, there are three main breeding and hibernating. If bats are slightly different habits, but this another widespread species, prefer types of roost: present during the summer, it’s seasonal pattern is common to all. older buildings where they are most often possible to see them fly out at The average bat maternity colony in often seen inside the loft in a small • Buildings, including houses, dusk, or perhaps even hear them Britain contains about 50 bats and cluster at the top of the roof ridge. churches, farms, ancient inside the roost on hot days or monuments, fortifications and all Important hibernation sites can be protected with specially designed grilles. Tony Mitchell-Jones/Natural England sorts of industrial buildings. before they emerge in the evening. These are most important in Often, though, you will have to look summer, but some are used for signs of bats rather than the throughout the year. animals themselves. The most characteristic signs are droppings. • Caves, mines and other These are roughly the size and underground places like cellars, shape of mouse droppings but, ice houses and tunnels. unlike mouse droppings, they These are most important for crumble to a powder when dry. hibernation as they give the They’re generally found stuck to sheltered and stable walls, in small piles beneath where conditions that bats need. the bats hang, or beneath 8 the roost exit. 9 1 End tiles 2 Barge board 3 Soffit 4 Gable end 6 5 Porch 8 6 Lead flashing 1 7 Hanging tiles 8 Ridge tiles 2 13 9 Broken tiles 10 Eaves 3 4 11 Sash window 10 frame 9 12 Wood cladding 7 11 13 Fascia board 14 Window sill 5 12 14

Conservation Most bat colonies live quite happily effective measure is to cover stored with their human landlords, but goods with dust sheets, which can be occasionally problems or concerns brushed off every now and again. arise. However, most bats are seasonal Outside, droppings stuck to walls and visitors and will leave of their own windows are usually a temporary accord within a few weeks. seasonal problem, but deflector boards fitted above doors or If you are unsure about having bats in windows can provide a solution. your roof, you should ask for advice from Natural England before doing Disease anything yourself (see Contacts, page British bats have few diseases that 22). We’ll give you free advice on how could affect humans and problems to solve any problems you might are very rare indeed. In recent years, have. You can also download a leaflet a tiny number of bats have been Living with bats from the Bat detected with a rabies-like virus Conservation Trust website or called European bat lyssavirus, which request a hard copy from their can infect humans. For this reason, National Bat Helpline (0845 1300 228). you are advised to avoid skin contact with bats or their saliva. Bats rarely Droppings come into contact with people, but if Bat droppings can be unsightly, you are bitten or scratched by a bat though in Britain there is no known you must seek immediate medical health risk associated with them. In advice. Having bats in your roof

the loft, the simplest and most cost- carries no risk from this virus. Noctule bat, a tree-dwelling species. Hugh Clark/FLPA 10 11 Pipistrelle nursery colony in a house roof. The young bats are grey. R. E. Stebbings/NHPA

Bats in rooms carefully. In both cases you should Bats generally come and go from their wear gloves. Carry the bat outside, roosts without any trouble, but away from houses, cats and people, occasionally turn up inside the house. and release it, preferably at dusk. This seems to be most common when baby bats, which are tiny and grey, If more than one bat turns up inside crawl out of their roost and find their your house, it's most likely that way into a room. However, there are also cases of young, inexperienced, bats they're crawling in from a nursery flying in through windows by mistake. roost. In this case, block up any holes inside the house the bats might be using, such as the gaps If a bat is flying inside a room, open around water pipes. However, you the doors or windows to allow it to must never block external entrance escape. If it has settled, remember and exit points used by bats. To do that you are advised to avoid direct so would risk trapping the bats and contact with bats and seek advice this would be illegal. If you’re not from your nearest Natural England sure what to do, contact Natural office (see Contacts, page 22). England for advice. Noise and smell If you have to remove a bat from a Bats rarely cause any problems with room or anywhere else, place a regards to noise or smell. Large small box or other container over colonies of pipistrelles can be noisy the bat and slide a piece of during the summer – especially if cardboard underneath to trap it. they’re behind cladding outside a Alternatively, cover the bat with a . S.C. Bisserot/Nature Photographers Serotine bat. S.C. Bisserot/Nature Photographers bedroom window – but this only lasts soft cloth or towel and gather it up 12 13 for a short time before the colony Repairs, re-roofing, begins to move out. Bat droppings do not normally smell strongly, but can insulation and do if they get wet. This might be alterations because the droppings are in a very confined space with little ventilation, As they depend so much on buildings, or because a building defect is bats need our tolerance and help to allowing the damp in. In either case, survive. This is mostly just a matter of seek advice from Natural England leaving the bats undisturbed, but before taking any action (see Contacts, repairs, maintenance and alterations page 22). to buildings can affect both bats and their roosts. In these cases, a little Damage forethought can usually minimise the It’s almost unknown for bats to cause problems. damage to houses. Unlike birds, they don’t bring in material to build nests If you think you have a bat roost in and, unlike mice or squirrels, they your house and want to carry out don’t gnaw wood or electric cables. work such as cavity wall insulation, Nor do they create entrance holes, re-roofing, roof repairs, alterations in they just take advantage of existing the loft, wall repointing or making gaps. Once inside the roost, they cling repairs to eaves or cladding that on to the timbers or squeeze might affect bats, seek advice from themselves into cracks and crevices. Natural England before starting. In Most bat colonies are small, with the most cases, it's just a matter of average colony of 50 bats weighing in organising the timing of the work to at well under 500 grams (1 pound). avoid the bats’ breeding season and

Daubenton’s bat, emerging from tree hole. Hugh Clark/FLPA Brown long-eared bat in flight. Stephen Dalton/NHPA Brown long-eared bat in flight. Stephen Dalton/NHPA 14 15 treatment company and consult Bats out of doors consult Natural England before Natural England for advice about the starting work (see Contacts, page 22). types of chemicals to use and when to Underground Also, try not to go into such places apply them (see Contacts, page 22). Many bats rely on underground sites during the winter if you think bats such as caves, mines, tunnels, cellars may be hibernating there. Burglar alarms and ice houses for hibernation or, Sometimes, bats flying in buildings can occasionally, breeding. Unfortunately, Bat grilles set off burglar alarms, including those these sorts of places are sometimes Underground sites, such as caves, that use light beams, microwave or deliberately blocked up for safety mines, cellars or tunnels, can be ultrasonic detectors or passive infra- reasons or accidentally blocked by protected with specially designed red (PIR) sensors. Persistent problems people dumping rubbish. When this grilles which will keep people out but happens, bats lose a hibernation can usually be solved by moving the site allow bats in. These need to be built to detectors, installing additional sensors or, worse still, are sealed up inside. a tested specification and fitted or changing the system, for example to If you’re planning to block, cap, grille carefully. If you know of a site that modern pulse-count detectors, which or demolish any sort of underground needs protecting, contact Natural are resistant to false alarms. place which might be used by bats, England for detailed advice. Greater horseshoe bat in flight. Stephen Dalton/NHPA Barbastelle bat, one of our rarest species. S.C. Bisserot/Nature Photographers Churches leaving roosts and access points unaltered so the bats can return in Most churches, certainly those in following years. If you want to carry southern England, are used by bats at out works in a way or at a time that will some time of the year. However, affect bats or their roosts you will need despite the saying, bats are rarely a licence from Natural England (see found in belfries which are too Contacts, page 22). exposed and draughty. In most cases, the number of bats is small and the Remedial timber treatment only problem is a scattering of Treatment for woodworm or rot can be droppings, which can easily be swept a hazard to bats if carried out with the away. Occasionally, urine spotting wrong sort of chemicals, or at the appears on brass, marble or polished wrong time of year. Fortunately, the surfaces. This staining can be situation has improved greatly over the minimised by treating floors or past decade with the introduction of polished surfaces with an emulsion new insecticides such as permethrin, wax polish, and brass with a which are much less poisonous to strippable lacquer. A few churches mammals. However, timber treatment may have larger numbers of bats and, still shouldn’t be carried out where here, specific advice on the bats are present. If you think bats use management of the colony may your building, tell your timber be needed.

16 17 Hollow and damaged trees Helping bats Bat Boxes houses, but don’t be disappointed if Mature and dead (or dying) trees often These are similar to bird boxes, but the box appears to stay empty. have hollow trunks or branches, and Here are some ways in with an entrance specially designed Boxes should be put up as high as these are important refuges for bats which people can give bats for bats. Ideally, they should be possible and face south to catch and other wildlife. However, they are a helping hand. placed in areas where there are a lot the sun. Your local bat group will be often ‘tidied up’ without any thought of insects for food, but few natural able to advise you, or you can for their value. Hollow trees should Bats in the garden roosting places, for example, a contact the Bat Conservation Trust always be left standing if possible, or Selective planting can help to conifer plantation. Bats will or Natural England for a leaflet on made safe by the lopping off of attract the insects that bats feed sometimes use boxes erected on bat boxes (see Contacts, page 22). branches. Even hollow branches on on. Especially useful are ponds healthy trees can be important for and night-scented flowers and Identifying bats bats. The same applies to trees that shrubs. Examples of the latter have been damaged by high winds, Even experts find bats difficult to identify, as most species look quite similar. The include evening primrose fire or lightning – these often contain ones that stand out from the crowd are long-eared bats, whose ears are almost Oenathera biennis, night-scented valuable roosting sites. as long as their bodies, and horseshoe bats, which sleep hanging upside down. stock Mattiola bicornia, lemon Bat boxes on trees in Cambridgeshire. balm Melissa officinalis, borage Britain’s bats (from most to least common) David Warren/FLPA Borago officinalis, honeysuckles Lonicera sp, and ivy Hedera Species in houses Frequency Main distribution Main roosts helix – there are many others. Common pipistrelle Common Throughout Britain Buildings, trees Soprano pipistrelle Common Throughout Britain Buildings, trees You can download a leaflet Brown long-eared bat Common Throughout Britain Buildings, trees Encouraging bats – a guide for Serotine Local Southern England Buildings bat-friendly gardening and living Lesser horseshoe bat Local S-W England & Wales Buildings, underground sites from the Bat Conservation Trust Natterer’s bat Uncommon Throughout Britain Buildings, underground sites website, or request a hard copy from the National Bat Helpline Whiskered bat Uncommon England and Wales Buildings, underground sites (see Contacts, page 22). Daubenton’s bat Uncommon Throughout Britain Buildings, underground sites Noctule Uncommon England and Wales Trees House roosts Greater horseshoe bat Rare S-W England & Wales Buildings, underground sites You can make your house Leisler’s bat Rare England Buildings accessible to bats by providing Brandt’s bat Rare England and Wales Buildings, underground sites entrances in the right places, Barbastelle Rare England (south) Trees, underground sites but it’s just a matter of chance if Grey long-eared bat Very rare Southern England Buildings bats find them. Access holes Bechstein’s bat Very rare Southern England Trees, underground sites should be no larger than 20 mm Nathusius’ pipistrelle Very rare Throughout Britain? Buildings wide and the best places to put them are along eaves near the corners of buildings or at Greater mouse-eared bat Extinct? Southern England Buildings, underground sites 18 gable apexes. 19 Bats and the law

All bats and their roosts are fully protected by the Wildlife & Countryside Act 1981 (as amended) and the Conservation (Natural Habitats &c.) Regulations 1994 (as amended). We recommend that you consult You must not: Natural England • Deliberately kill, injure, catch or keep bats. before you do anything that • Damage or destroy bat roosts. might affect bats Deliberately disturb bats, for example, by or their roosts • entering known roosts or hibernacula. (see Contacts, page 22). • Sell, barter or exchange bats, alive or dead.

Remember that, because bats return to the same places year after year, a bat roost is protected even if there aren’t bats there all the time. The law allows you to tend Activities that affect bats: disabled bats or kill seriously • Blocking, filling or installing grilles over old injured ones. mines or tunnels. Other activities, such as catching, • Building, demolition, alteration or ringing or maintenance work. photographing • Getting rid of unwanted bat colonies. bats or disturbing them whilst • Removal of hollow trees. roosting, can be licensed by • Re-roofing. Natural England • Remedial timber treatment. provided they are undertaken for • Re-wiring or plumbing in roofs. scientific, educational • Cavity wall insulation. or conservation • Treatment of wasps, bees or cluster flies. reasons. Trees like this dead oak provide valuable roosting places for bats. Walter Rohdich/FLPA places for bats. Walter Trees like this dead oak provide valuable roosting 20 21 Contacts The Vincent Wildlife Trust Tel: 01531 636 441 Natural England www.vwt.org.uk 1 East Parade Sheffield, S1 2ET Bat Conservation International (BCI) Enquiry Service: 0845 600 3078 P.O.Box 162603, Austin, TX 78716 USA [email protected] www.batcon.org www.naturalengland.org.uk

Bat Conservation Trust Further Information 15 Cloisters House This is one of a range of wildlife 8 Battersea Park Road gardening booklets published by London, SW8 4BG Natural England. For more details, National Bat Helpline: 0845 1300 228 [email protected] contact the Natural England Enquiry www.bats.org.uk Service on 0845 600 3078 or e-mail [email protected] The Bat Conservation Trust is the only organisation solely devoted to the Natural England also produces conservation of bats and their habitats Gardening with wildlife in mind, in the UK. A range of information an illustrated wildlife reference. leaflets is available to download from Originally on CD but now also the website or upon request from the available on-line, Gardening with helpline. wildlife in mind has detailed information on 800 plants and Bat Groups animal species often found in our Most counties have local bat groups gardens, and shows how they are which are involved in a range of practical ecologically linked. See conservation projects to help bats. New members are always welcome. Contact www.plantpress.com the Bat Conservation Trust (details above) for the name of your local group. Other titles Brown long-eared bat in house roof. John Hawkins/FLPA Bat boxes – a guide to their history, The Mammals Trust UK function, construction and use in the Encouraging bats – a guide for bat- Bats 15 Cloisters House conservation of bats friendly gardening and living. Phil Richardson. 8 Battersea Park Road Stebbings, R. E. & Walsh. S. T. Bat Conservation Trust Whittet Books. 2000 London, SW8 4BG Bat Conservation Trust. 1991. Tel:020 7498 5262 Bats in the garden www.mtuk.org Bats in houses Living with Bats Shirley Thompson. A. M. Hutson. Bat Conservation Trust School Garden Company. 1996. Bat Conservation Trust. 1993. 2022 2321