Daubenton's bat (Myotis daubentonii)

French: Murin De Daubenton
Spanish: Murciélago Ratonero Ribereño
GenusMyotis (1)
SizeHead/body length: 45 - 55 mm (2)
Tail length: 31 - 44.5 mm (2)
Forearm length: 35 - 41.7 mm (2)
Ear length: 10.5 - 14.2 mm (2)
Wingspan: 240 - 275 mm (2)
Weight7 - 15 g (2)

Daubenton's bat is classified as Least Concern (LC) on the IUCN Red List (8). In Great Britain, all bats are fully protected under Schedule 5 of the Wildlife and Countryside Act (1981) as amended, and by the Conservation (Natural Habitats &c.) Regulations (1994). An agreement on the Conservation of Bats in Europe (EUROBATS) under the auspices of the Bonn Convention, also known as the Convention on Migratory species (CMS) is in force, and all European bats are listed under Appendix II of the CMS (4).

Daubenton's bat (Myotis daubentonii) is a medium to small-sized species (2). The fur has a fluffy appearance, is brownish-grey to bronze on the back, and silvery grey on the belly (2). The ears, which are held folded at right angles if the bat is agitated, and the wing membranes are greyish brown in colour; the nose and face is reddish pink, and there is a bare area around the eyes (5). Juveniles are darker in colour than adults (2). The large feet are bordered with long bristles (2).

Widespread throughout Britain, reaching northern Scotland. Daubenton's bat is also widespread throughout much of Europe, extending as far east as Japan and Korea (5).

Daubenton's bat is associated with water bodies such as rivers and canals (7), and found mainly in flat countryside, particularly in woodlands (2). Summer colonies occur in underground tunnels, caves, cellars and mines, or underneath bridges, but are always near water (5). Tree holes and bat boxes are also used. They hibernate during winter in caves, mines and other subterranean sites (5).

Bats are the only true flying mammals. In Britain they are insectivorous (eat insects), and contrary to popular misconception they are not blind; many can actually see very well (6). All British bats use echolocation to orient themselves at night; they emit bursts of sound that are of such high frequencies they are beyond the human range of hearing and are called 'ultrasound' (7). They then listen to and interpret the echoes bounced back from objects, including prey, around them, allowing them to build up a 'sound-picture' of their surroundings (7). Daubenton's bats produce echolocation calls of frequencies between 35 and 85 kHz, but most calls peak at 45 to 50 kHz (5). They emerge at twilight, and with fast, agile flight they hunt over water, close to the surface (2), taking small flies, midges, mayflies (5) and moths (2). Daubenton's bats have been seen taking prey from the surface of the water using the tail membrane or the feet (5), eating the prey whilst flying (2).

Mating tends to occur in autumn (5), but fertilisation is delayed until the following spring (7). Female Daubenton's bats gather into maternity colonies in summer, the young bats are suckled for several weeks, reaching independence at around 6 to 8 weeks of age (5). Males and non-breeding females may gather into communal roosts in the summer, or they may live in the maternity roosts (5), but in separate groups to the breeding females (7). Hibernation occurs between the end of September and late March or April (2). Daubenton's bats are known to live to a maximum of 20 years, although the average life expectancy is closer to 4 to 4.5 years (2).

Removal of waterside trees and disturbance of hibernacula (sites of hibernation) could pose problems for Daubenton's bat. However, it seems that Daubenton's bat is increasing in some parts of its range, possibly as a result of the increase in artificial water bodies (5).

In Britain, bats benefit from a very comprehensive level of legal protection (4). Under the Wildlife and Countryside Act it is illegal to intentionally kill, injure, take or sell a bat, posses a live bat or part of a bat, to intentionally (or in England and Wales, recklessly) damage, obstruct or destroy access to bat roosts. Under the Conservation Regulations it is an offence to damage or destroy breeding sites or resting places. Fines of up to £5,000 for every bat affected and up to six months imprisonment are in place for these offences (3).

Find out more about the conservation of this and other British bats: 

Amy Dunkley, The Bat Conservation Trust, London.

  1. Integrated Taxonomic Information System (ITIS) (October, 2009)
  2. Schober, W. and Grimmberger, E. (1987) A Guide to Bats of Britain and Europe. Hamlyn Publishing Group Limited, London.
  3. Morris, P. (1993) A Red Data Book for British Mammals. Mammal Society, Bristol.
  4. Bat Conservation Trust (August, 2002)
  5. Macdonald, D.W. and Tattersall, F.T. (2001) Britain's mammals- the challenge for conservation. The Wildlife Conservation Research Unit, Oxford University. Available at:
  6. Altringham, J.D. (1996) Bats: Biology and Behaviour. Oxford University Press, Oxford.
  7. Bats and the Law - a quick guide. Bat Conservation Trust (August, 2002)
  8. IUCN Red List (February, 2011)