Brown Long-eared
Plecotus auritus
Head - Body 37-52mm. Wingspan 230-285mm. Weight 6-12gms
Nottinghamshire's second most widespread bat is easy to identify with ears nearly as long as its body. The majority of
summer roosts are found in old buildings with large roof spaces. They are a very quiet bat and are difficult to pick up on
a detector, this is why there are also known as whispering bats. Long-eared bats can use their large ears to hear the
sounds of insects on a leaf which they then glean from its surface. They will also take prey from the ground. Their
catch is often taken to a feeding site which can give away its location by the quantity of moth wings and other insect
remains found below it. Their winter quarters are in a variety of locations including buildings, tunnels, ice houses and
caves.
Photograph by Michael Walker
Distribution Map
Red dots = confirmed summer or winter roosts
Blue dots = unconfirmed roosts identified by droppings
Yellow dots = bats away from the roost
Echolocation Calls
Brown long-eared bats produce very quiet calls and often go undetected. They are however easier to hear if you have your detector pointed at a roost access. Their calls are short, 1.3ms to about 3.5ms, and on a heterodyne detector sound like rapid clicks. The frequency of maximum energy is around 39-40 kHz and there is often a cleat harmonic (see sonogram below). The calls on this page were recorded in September 2010 at the entrance to a roost of about 35 bats. Recordings were also made within the roost space.
Time expansion (10x) recording of a brown long-eared bat leaving the roost
Time expansion (10x) recording of four brown long-eared bats inside the roost space.
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