Grey long-eared bat  (Plecotus austriacus)

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 therefore 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). Grey long-eared bats are nocturnal, emerging from their roosts only after nightfall (2). They are extremely skilful flyers, and hunt for flying insects such as moths, small beetles and flies (2) (8). Like the brown long-eared bat, this species may take prey items taken to a perch to be eaten (2). Little is known of mating behaviour and reproduction in this bat. The mating season occurs in autumn, during which time males are territorial (7). Fertilisation is delayed until the following spring (7). Summer maternity roosts are small, containing 10 to 30 females, and a single young is produced in mid to late June (2). Hibernation takes place between September and April (6). The grey long-eared bat can live to a maximum of 14.5 years (2), but average ages of five years for males, and nine for females are more realistic (7).