Although very similar to the brown long eared bat the grey long eared bat is one of the rarest of British bats. Thought to be a different form of brown long eared bat it was classified a separate species in central Europe in 1960. Examples have a wing span of about 30cm a head/body length of about 4 -6cm with a tail about 4-5 cm long. As suggested by the name the animal has impressively large ears with ear length reaching 4cm in some animals, weight is between 7 to 14g. Identification can be difficult as it is so similar to the brown long eared bat although the grey tends to be slightly larger this isn’t always the case and colour among the grey bats does vary. Generally the Grey bat has long grey fur with pale belly fur, while wings and ears are black; the grey also has much smaller feet and thumbs than the brown bat.
Like most species of bat grey long eared bats are nocturnal and have been known to take prey back to a perch to be eaten. Mating season is in autumn with delayed fertilisation as the animals hibernate from September to April depending on weather conditions. A single young is born in the following summer normally around mid to late June, in maternity roosts which can contain up to thirty females. The average life expectancy is five years for a male and nearly twice that for the females but much longer lived individuals are not unheard of.
In the UK the Grey long eared bat is very rare found on the Channel Islands and the Isle of Wight with some colonies on south coast of England although several populations have disappeared in the last 30 years. In Europe it is much more common especially in southern Europe becoming increasingly rare as you head north into central Europe and rarely seen in Northern Europe. It is a woodland species, but has been known to roost in old buildings. Harsh winters in the UK have damaged populations as well as the usual threats from habitat loss and pesticides especially the use of pesticides inside buildings where they are roosting which can be fatal for bats for up to 20 years after treatment.
Grey long eared bats feed on small insects, gnats and moths predominately those found in woodlands, as mentioned earlier they have been known to take larger prey back to a perch to be eaten. The Grey long eared bat is an endangered species in the UK and like all Bats in the UK has legal protection with considerable fines for harming them or disturbing roost sites
For more on British bats see the Bat Conservation Trust: http://www.bats.org.uk/