Bechstein's bat (Myotis bechsteinii)
|French:||Murin De Bechstein|
|Spanish:||Murciélago Ratonero Forestal|
|Size||Body length: 45-55 mm (2)|
Wingspan: 250-300 mm (2)
|Weight||7-14 g (2)|
Bechstein's bat is classified as Near Threatened (NT) on the IUCN Red List (1). European populations are listed under Appendix II of The Bonn Convention (1), Appendix II of the Bern Convention, and Annex II and IV of the EC Habitats and Species Directive. In the UK it is protected under Schedule 5 of the Wildlife and Countryside Act 1981, and Schedule 2 of the Conservation Regulations, 1994 (3).
The rare tree-dwelling Bechstein's bat (Myotis bechsteinii) has long, broad ears with a long lancet shaped tragus (a soft cartilaginous projection in front of the ear). Adults have quite long fur, which is pale to reddish brown on the dorsal surface and light grey on the ventral surface. Juveniles are light ashy-grey (2). The wings are short, relatively broad and light brown to grey in colour. Partial albinism may occur, in which the wing tips are white (2). When threatened, hollow humming or chirping calls are produced; in flight this species does not make audible calls. Bechstein's bat produces 2 types of echolocation calls when flying; short FM signals between 80-38 kHz and flat, longer FM signals at 60-32 kHz (2).
Patchily distributed throughout central Europe, France, Belgium, the Netherlands, Germany, southern Sweden and the Mediterranean region, but Bechstein's bat is rare throughout its range (2). In the UK it is restricted to southern England; important locations occur in Devon, Dorset, Gloucestershire, the Isle of Wight, Somerset and Wiltshire (3). Recently a there have been a couple of recordings in Wales and several roosts were found in Surrey in 1997 (3).
Mainly found in old growth broadleaved woodland, Bechstein's bat tends to roost in trees, bat boxes and rock crevices throughout the year, and they may hibernate underground (4).
This bat emerges after nightfall and sets off in pursuit of prey; favourite items include moths, mosquitoes, and beetles. When hunting, Bechstein's bat flies low and picks prey from the ground or from twigs (2). The mating season occurs between autumn and spring, nursery roosts are occupied from the end of April/ May, and births occur towards the end of June (2). One young is produced which is able to fly by mid-August. (2).
Bechstein's bat is rare in the UK with only one maternity roost and fewer than 20 hibernation roosts known at present. The population is estimated to be in the region of 1500 (3). The threats currently facing this species are not understood but it is vulnerable to loss and fragmentation of open old-growth broadleaved woodlands and disturbance or loss of roost sites (3).
Bechstein's bat is listed under English Nature's Species Recovery Programme, which includes a scheme that provides and monitors bat boxes for this species in Dorset and Wiltshire where there is a lack of roosting sites. Some hibernation sites occur within SSSIs, others have been protected against disturbance. Bechstein's bat is a priority species under the UK Biodiversity Action Plan. The Action Plan for this species aims to maintain the known range and population level, and improve the age structure of woodlands to maximise roosting and foraging chances (3).
For more on British bats:
The Bat Conservation Trust:
The Vincent Wildlife Trust:
Information authenticated by the Bat Conservation Trust:
- Albinism: heritable (passed on from one generation to the next) genetic condition in which the pigment melanin is not produced in the skin or hair resulting in white, or partially white individuals.
- Echolocation: detecting objects by reflected sound. Used for orientation and detecting and locating prey by bats and cetacea (whales and dolphins).
- Hibernation: a winter survival strategy characteristic of some mammals in which an animal's metabolic rate slows down and a state of deep sleep is attained. Whilst hibernating, animals survive on stored reserves of fat that they have accumulated in summer. In insects, the correct term for hibernation is 'diapause', a temporary pause in development and growth. Any stage of the lifecycle (eggs, larvae, pupae or adults) may enter diapause, which is typically associated with winter.
- Tragus: a soft cartilaginous projection extending in front of the external opening of the ear. In bats it is thought to aid in the location of prey by generating many echoes, but the precise way in which this works is unknown.