Distributed in West, Central and Eastern Europe. In the Balkans the density is locally higher. Outside Europe, Bechstein’s Bat occurs locally on the southern coast of Anatolia, on the Black Sea coast and in the Caucasus, as well as in northern Iran.1 In Bulgaria it is rare, but the bat can be found throughout the country.
A medium-sized bat with remarkably long ears (21 – 26 mm). They have 9 – 11 transverse folds which are well separated from each other. Thе long tragus reaches about half the length of the ear. The dorsal fur is brown to reddish-brown and is clearly demarcated from the bright beige or grey ventral side. The face is reddish-brown, the other skin parts are pale brown.
2.5 – 5 ms long calls descend from 80 kHz to 35 kHz. Distinction from other Myotis species is only possible on the basis of sound recordings and longer sequences or in combination with good visual observation.
Bat of oak forests and temperate beech forest zones, occurring in deciduous woodlands from lowlands up to high mountain ranges. In Bulgaria occurs in deciduous woodlands and mixed forests. Bechstein’s Bat is a very sedentary species and summer and winter roosts usually lie only a few kilometers from each other. A nursery colony is used by about 20 animals. The distance between the hunting grounds and the roosts differs considerably and is dependent on the habitat (1 to 2,5 – 10 km). Sometimes males hunt within only a few hundred meters from the roost tree. The hunting areas of the females are larger. Hunting sites are visited very faithfully in different seasons by the same individuals.
The roosts are located in tree holes, trunk crevices and frequently in bird and bat boxes. Natural tree roosts can be close to the ground and are often in woodpecker holes in oak trees.
Nursery colonies are formed in April. The birth of the young is from the beginning of June to the beginning of July. Nursery colonies disperse in the end of August. They can roost together with Natterer’s and Daubenton’s Bats. The nursery colonies subdivide frequently, recombine and subdivide again. Roosts are changed every 2 – 3 days. Young females usually join their natal colony. Young males move away from their area of birth. Bechstein’s Bats swarm at underground sites with a peak in the middle of August. Mating also takes place here.
Their hunting flight is very close to the vegetation on the ground (1- 5 m). They are maneuverable animals, which can fly very slowly and hover. Frequently collect prey from the substrate. Detection is based on the scuffling sounds of the prey, which are detected with the large ears. The food consists of non-flying insects, moths, beetles, Diptera (crane-flies), lacewings and spiders.
Bechstein’s Bats cross open spaces, roads where they can meet danger. Specialized road constructions must be made to ensure their protection.
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”.