In Central and Eastern Europe, in some parts of Western and Southern Europe and Asia. Occurs eastwards over the Caucasus and Iran into Mongolia, north-east China, Korea, Afghanistan and northern Pakistan.1 In Bulgaria the distribution is unclear. Probably in the whole country.
Medium-sized bat with long fur. The dorsal fur is black-brown with silver-whitish tips. The ventral side is whitish or brownish-yellowish and clearly delineated from the dorsal side. The face, ears and membranes are blackish-brown. Ears are rounded and short. The tragus is short and broad. This is the only European species with two pairs of mammary glands.
Up to 25 ms long QCF calls with peak frequencies between 22 and 27 kHz, FM-QCF calls from 23.5 – 29 kHz. From late autumn to early winter the characteristic display calls start with up to 10 FM calls about 3 ms long, followed by a declining 25 ms long call from 30 kHz to 10 – 15 kHz. Very clearly audible with naked ear over distances of up to 50 m.
In mountain forests, open agricultural areas, villages and cities. They are migratory species – long distances, over 1000 km. Hunting grounds of males are larger and far from the roost, the hunting grounds of the females are smaller and closer to the roost.
Roosts are in crevices of buildings, roof voids, rock crevices, tree holes and bat boxes.
Nursery roosts are formed in May and usually comprise of 20 – 60 individuals, but the number can be up to 200 females. The young are born in May and June. Females give birth to twins, exceptionally three young and rarely only one. Males also form groups, sometimes far away from the nursery roosts. Mating takes place in late autumn.
The flight is fast and direct at a height of 10 – 40 m. Hunting grounds are over water bodies, meadows, riparian zones and around human settlements. The hunting grounds of individual animals overlap markedly. The food consists of small Diptera, moths and other flying nocturnal insects.
In Western and Southern Europe known reproductive colonies are very thinly spread and they need protection. Threats are the renovation of buildings and wind farms during the migration of the species.
Christian Dietz and Andreas Kiefer (2014), “Bats of Britain and Europe”;
Vasil Popov, Atila Sedefchev (2003), “Mammals in Bulgaria”;
Vasil Popov, Nikolay Spasov, Teodora Ivanova, Borqna Mihaylova and Kiril Georgiev (2007), “Mammals important for conservation in Bulgaria”.