Bat of the Month – Vol. 1: Brown Long-eared Bat (Plecotus auritus)
A medium sized bat, who’s most distinctive feature is its long ears. This trait is shared with the similar, but larger and more rare, Grey Long-eared Bat, yet the Brown Long-eared Bat is discernable by its light brown dorsal fur (although juveniles can appear greyish).
The Brown Long-eared Bat’s ears are nearly as long as its body, but can catch observers off guard when roosting, i.e. they can either be curled back, resembling ‘rams’ horns’, or retracted completely under their wings. When tucked away as such, the tragus remains visible, deceptively resembling an ear!
Brown Long-eared Bats have been termed ‘whispering bats’ as a consequence of their quiet calls. These have a low echolocation frequency, with peak frequency ranging from approximately 25 – 50 kHz, picked up as a series of quiet clicks. The bat has particularly sensitive low frequency hearing, and is capable of targeting its insect prey based on the sound emitted by the insect’s own movements
Brown Long-eared Bats will take prey on the wing given the opportunity, but are known to be ‘gleaners’, and will flutter slowly whilst carrying out agile manoeuvres to navigate vegetation and ‘glean’ insects from leaves, bark and other surfaces.