BROWN LONG-EARED BAT Plecotus auritus

 

Status: Native; Common

 

Habitat: Woodland

 

A medium sized brown bat, characterised by extremely long ears (3-4 cm in length when erect, such as in flight or when alert).  At rest the ears are curved back into a ram’s horn shape, and are often tucked under the arms at rest or in hibernation. 

 

This is typically a woodland species, although it also occurs within parkland and in large gardens.  It has very broad wings to aid slow, manoeuvrable flight; even allowing the bat to hover.  It uses its large ears to listen for insects, which are often gleaned from the surface of leaves and other vegetation.   Moths form a large part of the bat’s diet, and as many moth species can hear the ultrasound of approaching bats (and can take evasive action), Brown long eared bats often hunt with their ultrasound ‘turned off’.  The large eyes of this species help with prey detection.

 

Summer and nursery roosts may comprise churches, and the lofts of barns and old buildings, where they often group along the main ridge beam.  Many of these roosts are also occupied in the winter, although caves, mines and tunnels are also used for hibernation.  This species also uses holes in trees and bat boxes can be occupied, although rarely in large numbers. 

 

Nursery roosts typically comprise 10-50 bats (a relatively low number); and both males and females may be present in equal numbers.  Long-eared bats show a high degree of roost fidelity; long terms studies have shown that less than 1% of ringed bats leave the roost in which they were ringed.

 

Long-eared bats to emerge from their roosts relatively late, and seldom return during the night; instead using a number of ‘night roosts’ (temporary shelters used to rest during the night, but not in the day).  Prey are often taken to these night roosts to be dismembered and eaten, and a large accumulation of discarded moth wings, for example, can give away their presence.

 

Most foraging is carried out within 500 metres of the roost, and only very rarely more than 3 km away from the roost.  Hedgerow links and tree lines are thought to be very important, as this species does not like to cross expanses of open ground where it is vulnerable to predation (being a relatively slow-flying species).

 

The British population of Brown long-eared bats is estimated to be around 200,000, making it the third commonest species in most of the country.