Britain's official guide to canals, rivers and lakes

Friday 9th January 2009

Bat

Pipistrell Bat, courtesy of Mike Hammett/English Nature

Bram Stoker has a lot to answer for! Bats have suffered a lot of bad press thanks to their fictitious association with vampires and witchcraft.

In fact, British bats are entirely harmless and their insect-oriented diet makes them more friend than foe of human creepy-crawly haters.

Bats make up a quarter of all mammal species, with nearly 1,000 different bat species existing across the globe. 16 of these can be found in Britain, the most common being the tiny pipistrelle which weighs less than a 2 pence coin. In the halcyon days when Britain was covered in trees, bats often roosted in hollowed-out tree trunks or caves. However, now that so much deforestation has taken place, bats have been forced to seek alternative roosts such as empty buildings, lofts and even canal bridges.

Bats can sometimes be spotted around dusk as they venture out to hunt their insect prey. They use a highly sophisticated form of radar (or high frequency squeak) which bounces off objects back to the bat and imparts information regarding the size, location, velocity and even texture of whatever is in the bat's path. Bats are less likely to be seen during the winter months when they hibernate in cool and humid shelters. During this time the bat's body system will slow down and its heart rate drop. It is important not to disturb any bats during hibernation as the act of waking will use up vital fat reserves, which are needed to sustain the bat until spring.

Take part in British Waterways' 2008 National Wildlife Survey

Facts

Appearance: Bats often display characteristics peculiar to their species, for example the long-eared bat has unusually lengthy ears. In Britain, the most common bats have a small body, short legs, fairly narrow wings and a short tail. Colours vary from colony to colony, but ears and muzzle are dark and body hair a shade between orange-brown and grey-brown

Size: Again, this is dependent on species. Pipistrelle bats measure 3-5cm with a wingspan between 19-25cm. The greater horseshoe bat and the noctule bat have a wingspan up to 38cm

Weight: 3-9g (Pipistrelle)

Lifespan: Average 4-5 years

Diet: Small flying insects

Family: Chiropetra - meaning hand-wing in Greek. This is an apt description, as the bone structure of a bat's wing resembles extended human fingers with the skin stretched tight between them up to the fingertips

Did you know?

  • The largest bats have a wingspan measuring up to six feet. Thankfully, these giants are not found in the UK
  • With its wings folded, the pipistrelle could fit inside a matchbox
  • In some parts of the world, bats have been known to live up to 33 years
  • Despite the saying 'blind as a bat', bats actually have reasonable eyesight
  • Similarly, bats rarely live in belfries. They prefer quiet places with few draughts and therefore can often be found roosting in modern houses
  • Bats are the only mammal capable of controlled flight. They have impressive aerobatic ability and are very unlikely to get caught in your hair
  • Bats found living in your loft or under the eaves should not be a cause for concern. They will make their home in existing crevices and not damage property by building nests. Remember, bats and their roosts are protected by law and must not be disturbed in any way