Grey long-eared bat
Grey long-eared bats are very rare medium sized bats found only in a few places in southern England. They are one of two long-eared bat species in the UK.
The scientific name of the grey long-eared bat is Plecotus austriacus.
Grey long-eared bat IUCN classification
GB: Endangered
England: Endangered
Scotland: NA
Wales: NA
Global: Least concern
Vital statistics
Head & body length: 41mm - 58mm
Forearm length: 37mm - 45mm
Wingspan: 255mm - 300mm
Weight: 7g - 12g
Thumb: 5mm - 6.5mm
Tragus: 5.2mm - 6.6mm
Colour: Larger and greyer than the brown long-eared bat - sometimes confused with juveniles of the latter. Face often darker with a blackish mask.
General information
Grey long-eared bats are generally a little larger than the brown long-eared bat and have a dark face.
A grey long-eared bat’s ears are nearly as long as the body, but are not always obvious; when at rest they curl their ears back like rams horns, or tuck them away completely under their wings leaving only the pointed inner lobe of the ear (the tragus) visible.
The most reliable distinguishing features between brown and grey long-eared bats are dorsal hair colour (dark and light bands along the hairs in the brown long-eared), the length of the thumb, the ratio of the length of the thumb to the length of the forearm, the width of the tragus, and face colour (pinkish- brown in the brown long-eared bat) and shape (grey long-eared bats have a longer and darker muzzle).
Since the northern edge of the grey long-eared bat’s distribution is 53°N, bats found above this latitude are more than likely brown long-eared bats, which are far more common and widespread in Britain.
Grey long-eared bat habitat
Relatively little is known about the habitat use of the grey long-eared bat. Radio-tracking studies show that they tend to forage over meadows, grasslands, gardens and near forest edges, up to 6 km away from the roost.
Grey long-eared bats are most often found in older houses with large open roof voids which allow the bats to fly around in the roof. Bats can be found in these roosts throughout the year, though numbers are higher in the summer. As well as using the roof void, the bats will tuck themselves away behind rafters, so they may not always be seen. A favourite roosting place is on or above the ridge beam of the roof and a line of droppings beneath is often a good indication of their presence.
In winter, grey long-eared bats may still be found in roofs in small numbers and some are seen in underground sites such as caves, mines and cellars.
Although the two species have similar wing morphology, the grey long-eared bat mainly forages in open spaces and catches prey in flight. The brown long-eared bat mainly forages in woodlands and gleans prey from the vegetation.
Diet
Grey long-eared bats eat moths, Diptera (mainly Tipulids – crane flies), small beetles.
Reproduction and life cycle
As with other species, long-eared breeding colonies gather in roosts during April and May.
Generally, grey long-eared bat numbers are quite low, averaging about 20 adults, but colonies of up to 100 are known. Males are often found in these roosts and are obviously tolerated by the females. The single baby is born in the end of June/beginning of July and is able to fly by August.
Echolocation of grey long-eared bat
The grey long-eared bat emerges in darkness and, like the brown long-eared, is a very skilful flier.
The echolocation pulses produced by these bats are very quiet - this is thought to help with finding insects on foliage as well as to avoid warning moths of the presence of the bat.
Call duration: 1.7ms, Minimum frequency: 29.8kHz, Maximum frequency: 62.5kHz
Distribution and conservation
Range Map: Fourth Report of grey long‐eared bat (Plecotus austriacus) by the United Kingdom under Article 17, JNCC (2019)
The grey long-eared bat is a southern European species, with a distribution extending from the northern Mediterranean coast in the south to southwest England and the Black Sea coast in the north (up to latitude 53ºN). In England, grey long-eareds are restricted to a few colonies in Sussex, Hampshire, the Isle of Wight, Dorset, Devon and Somerset.
Although grey long-eareds are widespread in southern Europe and have a Lower Risk Least Concerned global conservation status (IUCN Red List 2009), it is extremely rare in countries at the northern edge of its range.
There are no specific conservation management plans for the grey long-eared bat in Britain, despite this species rarity, partly due to a lack of information on its behaviour and ecological requirements in Britain.
The Back from the Brink programme (2017-21) was an ambitious nationwide partnership initiative that aimed to save some of our most threatened species from extinction. As part of this project, the Bat Conservation Trust developed a single species project that aims to reverse the decline of the grey long-eared bat. A number of useful resources were produced about the grey long-eared bat which you can access here.
