The Brown Long-eared bat is a medium-sized bat, it weighs 6-12g and can live up to 30 years!
Its wings and tail are broad, this allows slow, highly manoeuvrable and hovering flight.
Its ears are nearly as long as it’s body, but when asleep or in hibernation the Brown Long-eared bat will tuck the ears under the wings so only the tragus is showing.
Did you know…? In the Netherlands the Brown Long-eared bat is called “bruine grootoorvleermuis” literally translated as brown (bruine) big (groot) ear (oor) bat (vleermuis)!
The Brown Long-eared bat is also common and widespread in the rest of Europe, except for southern Spain, southern Italy and Greece.
Mating takes place in Autumn, with males also seeking out females during the winter hibernation period.
Brown Long-eared bats (like all bats in the UK) are one of the few mammals that are true hibernators. During hibernation Brown long-eared bats are not really asleep, instead they drop their body temperature to match their surroundings and become torpid [a state of physical or mental inactivity; lethargy]. This strategy enables them to save energy during the winter when food is scarce but slows down all other bodily functions making normal activity impossible.
Did you know…? Hibernation occurs between November and March. Brown Long-eared bats prefer to hibernate at very cold temperatures (just above freezing point!)
Did you know…? Female bats give birth to one pup a year. Juvenile Brown Long-eared bats can be easily confused with another species, the Grey Long-eared bat.
The pups are born in late June-early July and are weaned when about 6 weeks old.
Maternity colonies are established in late spring [where female bats gather to give birth and care for their pups]. These colonies can contain 10-30 individual bats.
Brown Long-eared bats and all bat species in the UK are insectivores. Each bat species will have different preferences, the Brown Long-eared bat’s diet for instance, is mainly comprised of moths, beetles, flies, earwigs and spiders.
Small prey is eaten in ﬂight
Large insects are taken to a ‘perch'
Regularly used perches, which are frequently inside porches or barns, can be recognised by the accumulations of discarded insect remains, particularly wings of moths such as yellow underwings.
It takes experience to identify bat droppings to a species, however if you try to crush a bat dropping it will disintegrate into dust. Whereas mouse droppings will not turn to dust but instead get harder. Brown long-eared bat droppings tend to be 2.5-3.0mm in diameter and 8-10mm in length with a knobbly outline.
Using a bat detector
Brown long-eared bat echolocation calls range from 25 - 50kHz with a peak at around 35kHz. On a bat detector the calls are very quiet and are heard as a series of clicks and sound very similar to a soft gentle purring.
Yellow Underwing moth wings can be found underneath a feeding perch, presence of other moth and butterfly species can also be found as Brown Long-eared and Barbastelle bats will take prey back to perches.
Did you know…? These bats are known as ‘whispering bats’ because their echolocation sounds are very quiet. They have particularly sensitive low frequency hearing and often locate prey from the sounds made by the insect’s own movements. They may sometimes use vision.
Habitat & Threats
The Brown Long-eared bat has declined in Britain due to changing land use, such as our modern intensive agricultural practices, and the conversion of barns which have resulted in the loss of suitable feeding and roosting habitats.
Brown long-eared bats tend to be found in rural and suburban areas, woodlands and farmlands but roosts have also been found in town centres.
Did you know…? Modern roofing membranes can entangle roosting bats leading to starvation and death.
It is particularly susceptible to pesticides, especially when used in roofs where the Brown Long-eared bat often roosts on exposed timbers.
Bat Conservation Trust
What can you do to help bats?
Local mammal groups
If you want to help Brown Long-eared bats or find out more information about them, then these websites might be of help: