Central and North Europe, in Scandinavia and Russia up to 65 °N. In Balkans it is limited to the mountains. Thе main distribution extends in a wide area of Russia up to the Urals and further eastwards. Isolated occurrence in the Caucasus. In Bulgaria in mountainous areas at altitude 950 – 1540 m.1
A small bat with long ears and long fur. The tragus is longer than half of the length of the ear. The young are different from the adults. The dorsal fur in older animals is light brown, mostly with gold-shining tips, the ventral side is not clearly demarcated from the dorsal side and is light grey coloured, with a slightly yellowish tinge. The bare skin areas are brownish. The adult fur is reached at the age of approximately seven years. The young animals are almost black and from year to year become increasingly lighter. The lower part of the tragus, the inside of the auricle and the base of the ear are paler. The penis of adult males is obviously club shaped at the end, in juvenile males it is already thickened. The penis of this species has a bulge that is missing in other species.
4 – 7 ms long frequency – modulated calls between 80 – 35 kHz.
The most important habitat for this species are forests (deciduous, mixed and coniferous forests) and water. In Bulgaria it occurs in mountain forests. Brandt’s bat does not migrate far, less than 40 km. It uses up to 13 hunting grounds of 1 – 4 ha, that are up to 10 km from the roost.
Summer roosts are in tree holes, cracks in trunks and behind peeling barks. Can be found in buildings close to forests. Winter roosts are in caves, mines and in rock storage tunnels.
Nursery colonies comprise of 20 – 60 females. The copulation is after lactation period or in the winter roosts. The birth of one single young takes place in June in Central Europe. From the beginning of August mainly males are present at swarming sites.
The flight is smooth and manoeuvrable. The bat hunts between branches, tree trunks and higher above the water surface. The food consists of moths, spiders and Diptera.
The destruction of their habitat on of roosts through redevelopment works and by forestry. Isolation of foraging units could be a further serious threat.
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”.