Bechstein's bat

GB: Least concern

England: Least concern

Scotland: NA

Wales: Endangered

Global: Nearly threatened

Head & body length: 43mm -53mm

Forearm length: 38mm - 47mm

Wingspan: 250mm - 300mm

Weight: 7g - 13g

Colour: Pale to reddish brown fur, greyish underneath. Pink face.

Until recently very little was known about the Bechstein’s bat in the UK. In 2005 there were just six breeding populations of Bechstein’s bat.

It is largely known as a woodland bat that captures much of its prey by passive listening for insect noise.

Being one of the rarest mammals, much remains to be learned about Bechstein’s bat.

Deciduous woodland provides most of the habitat for Bechstein’s bat - it uses woodland for roosting, foraging and almost certainly hibernation. Mature dense woodland is ideal, ensuring they do not often come into contact with people.

Bechstein’s bats tend to forage in woodland within a kilometre or two of their roost site, generally high up in the canopy. However, they are occasionally observed flying nearer the ground, perhaps when drinking, commuting or socialising.

In summer, Bechstein’s bat roosts largely in woodpecker holes, but sometimes behind loose bark or in tree crevices (also occasionally in bat boxes). It rarely roosts in buildings.

It is thought to hibernate in similar roosting sites to those it uses in summer, although perhaps in slightly deeper tree holes. It is also occasionally found in underground sites.

Bechstein’s bat eats prey from most insect groups. Droppings work on the Isle of Wight and in Wiltshire shows that it eats dung flies, grasshoppers and nut weevils, as well as moths and other types of flies.

Some individuals have been known to feed on non-flying insect larvae and spiders that are gleaned from vegetation and near to the ground, but this is atypical.

Bechstein's bat mating occurs in autumn and spring, with maternity colonies forming in April and May. Females gather in colonies of between 10 and 30 bats (and up to 100 in some cases), with babies born at the end of June to the beginning of July.

Maternity colonies are often spread across a number of roost sites, changing their location frequently throughout the summer.

Bechstein’s bats have been recorded as living up to 21 years.

The Bechstein’s bat has very quiet echolocation , and as a result is difficult to detect. The frequency of most energy is 50kHz, and the call sounds like ‘tik’.

Bechstein's bat is a very rare species, only found in southern Wales and parts of southern England. The UK is at the nothernmost edge of its distribution range.

The Bechstein’s bat has gone from being one of the commonest UK species after the last ice age to one of the rarest. This is due largely to the destruction of ancient woodland that once covered the UK (which now represents around 2%).

It is a UK Biodiversity Action Plan species, which means that it is a conservation priority on both a local and national scale. BCT is the lead partner for the Bechstein’s Biodiversity Action Plan.

Between 2007-2011, BCT carried out the Bechstein’s Bat Project, which aimem to establish baseline distribution data for this species across its UK range. Find out more about the Bechstein's Bat Project.

Bechstein’s bat is also listed on Annex II of the EC Habitats Directive, which requires deisgnation of Special Areas of Conservation (SACs) to promote important populations. In 2006 there were six SACs designated specifically for Bechstein’s bat.