Or BLE for short, these bats have HUGE ears! After pipistrelle species, these are the next most frequently found bat species, and pretty unmistakeable as the ears (about 1/3 of total length of the bat) are thrust forward in flight like small oval satellite dishes. They are slightly larger than Pipistrelles, with a wingspan of 230-285mm, weight of 6-12g and their wings are very broad. They hunt moths inside the canopy of trees and although not fast fliers are very agile. Their habitat is woodland and parkland.
They roost in relatively small numbers (maternity roost is around 10-50 bats) and they prefer hollow trees, or large open roof voids of usually old timber-lined barns or houses with roof trusses and frames. Presumably this gives a range of microclimates within the roof and the timber affords some insulation. Some have even taken up bat boxes, but more usually as hibernation sites. They hardly move away from this roost at all (range is about 3km maximum) and will often use their roost all year round. They do not leave their roost until well after dusk, when it is completely dark.
Their large ears are used to track their prey directly, so they do not echolocate very much, and if they do it’s very quietly so most bat detectors won’t pick them up at any sort of distance. For this reason they are sometimes called the ‘whispering bat’. They can conserve moisture and heat by contracting their ears and tucking them under their armpits, or leaving them looking like little ram’s horns.