The brown long-eared bat or common long-eared bat (''Plecotus auritus'') is a small
Eurasian insectivorous
A robber fly eating a hoverfly
An insectivore is a carnivorous animal or plant that eats insects. An alternative term is entomophage, which can also refer to the human practice of eating insects.
The first vertebrate insectivores were ...
bat. It has distinctive
ears, long and with a distinctive fold. It is extremely similar to the much rarer
grey long-eared bat
The grey long-eared bat (''Plecotus austriacus'') is a fairly large European bat. It has distinctive ears, long and with a distinctive fold. It hunts above woodland, often by day, and mostly for moths. In captivity, it has also been recorded t ...
which was only validated as a distinct
species in the 1960s. An adult brown long-eared bat has a body length of 4.5–4.8 cm, a tail of 4.1–4.6 cm, and a forearm length of 4–4.2 cm. The ears are 3.3–3.9 cm in length, and readily distinguish the long-eared bats from most other bat species. They are relatively slow flyers compared to other bat species.
Habitat
The brown long-eared bat is found throughout Europe, with the exception of Greece, southern Italy and southern Spain. It is found to the east up to the Urals and Caucasus. The UK distribution can be found on the
National Biodiversity Network
The National Biodiversity Network (UK) (NBN) is a collaborative venture set up in 2000 in the United Kingdom committed to making biodiversity information available through various media, including on the internet via the NBN Atlas—the data searc ...
website and can be see
here
Brown long-eared bats regularly utilise buildings roosting in undisturbed roof spaces either singly, in crevices and timber, or in clusters around chimneys and ridge ends. This species also roosts in treeholes, bat boxes and
caves which are important as winter hibernation sites. The roosts in trees may be close to the ground. Emergence from roost sites usually only occurs in the dark, around an hour after sunset.
It hunts above
woodland, often by day, and mostly for
moths, but its diet also consists of
earwigs, flies, and beetles, gleaning these insects from leaves and bark. Prey is probably detected by sight and sound using the large eyes and ears, not by echolocation. A study by Eklöf and Jones (2003) demonstrated the ability of the brown long-eared bat to visually detect prey. Under experimental conditions, brown long-eared bats showed a preference for situations where sonar and visual cues were available. However, visual cues were more important than sonar cues and the bats were unable to detect prey items using only sonar cues. Brown long-eared bats have relatively large eyes and ears and it is likely that visual information and passive listening allow this species to detect prey in cluttered environments.
Echolocation
Echolocation is not used to find prey. The frequencies used by this bat species for echolocation lie between 27–56 kHz, have most energy at 35 kHz and have an average duration of 2.5 ms. However, unlike most bats, the long-eared can hunt their prey by hearing alone. Their hearing is sensitive enough to hear a moth in flight. This hunting strategy evolved because prey items, namely certain moth species evolved the ability to hear the echolocation and take evading action.
Gallery
File:Haeckel Chiroptera Plecotus auritus 1.jpg, Drawing by Ernst Haeckel
File:Haeckel Chiroptera Plecotus auritus 2.jpg, Detail of head
File:Plecotus auritus ras.jpg, Woodcut from R. A. Sterndale, 1884
File:Braunes Langohr (Plectus auritus).jpg, Exemplar in the Oxford University Museum of Natural History
File:Plecotus auritus 2016 stamp of Romania.jpg, Romanian stamp
File:Plecotus auritus hibernate with one ear out.jpg
References
;Sources
Woodland Management For Bats Guide*
* (2005): The role of eyespots as anti-predator mechanisms, principally demonstrated in the Lepidoptera. ''
Biol. Rev.'' 80(4): 573–588.
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External links
ARKivePhotographs
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Plecotus
Bats of Europe
Mammals described in 1758
Taxa named by Carl Linnaeus