Barbastella barbastellus

Barbastella barbastellus
Barbastella barbastellus

Large parts of Europe, but with considerable distribution gaps in the Eastern Mediterranean. The northernmost occurrence is in Sweden, with only a single record from Norway. Also occurs on the Balearics, Corsica, Sardinia, the Canary Islands and in Morocco. The eastern border of the distribution lies in Eastern Turkey in Cappadocia, the Pontic region, and in the Caucasus. In Bulgaria – rare species in karst and forest areas.

Medium-sized bat with a short, blunt muzzle. The fur is dense, long and silky and dark black-brown. On the back the hairs have whitish tips. The skin areas are dark black-brown. The ears are broad with trapezium shape, and their bases are connected. The tragus tapers very abruptly at half its length and has a long, rounded tip. The mouth and the eyes are small.

There are two types of echolocation calls. Type 1 starts at 33.4-49 kHz, lasts maximum of 5 ms, and drops to 24-37 kHz. Type 2 strats at 37-47 kHz, lasts up to 10 ms, and drops to 24-37 kHz. Type 1 is much louder than type 2. The two call types are probably alternately emitted, either by a shift of the larynx or the soft palate, downward through the mouth for type 1 and upwards through the nostrils for type 2. At emergence, type 2 is exclusively emitted with the mouth closed.

Wide range of forests, but also in gardens near forests. In Bulgaria they live mostly in mountainous and semi-mountainous areas. This bat is a sedentary species, with summer and winter roosts lying close together, usually less than 40 km distance. The hunting grounds are near the nursery colonies. Young bats and old males hunt closer to their roost unlike adult females.

Summer roosts are in forests behind loose barks, in tree crevices and in flat bat boxes. Natural tree roosts occur usually in neglected dense-growth areas, or at least in near-natural forests with high old trees and standing dead wood, such as behind loose bark of oak, beech and spruce trees, usually at heights of 8-10 m. Roost sites are changed every two days on average. Winter roosts occur likewise behind barks, but also in caves, mines, disused railway tunnels, rock crevices and ruins. In Bulgaria the species prefers cold caves.

In the summer the females form small colonies of 10-20 animals in the crevices of the trees. The males live singly. Tree roosts are frequently changed. This bat species winters singly or in large colonies. Mating takes place in the late summer in mating roosts. Mating groups can be formed of one male with up to four females. In May-June, 1-2 young bats are born and suckled for up to six weeks.

The flight is agile, fast and close to vegetation. Rapid dives close to branches are observed in animals hunting above the tree canopy. The bats emerge early in the dusk. The food consists of small moths such as pyralids and tiger moths, plus a small proportion of Diptera, small beetles and other flying insects.

Intensive forest management, leaving little, old and dead wood, pesticide use in forests and increasing habitat fragmentation are causes of 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”.