Myotis myotis

Myotis myotis
Myotis myotis
Greater mouse eared bat

Europe, North to the Southern Netherlands, Schleswig-Holstein in Germany and Northern Poland. The eastern border in Europe runs through Ukraine to the Black sea and through Asia Minor in the Near East. Bulgaria – in karst areas. One of the most common cave species.

A large bat with a long, broad muzzle and long broad ears. The dorsal side is brown to reddish-brown, the ventral side is dirty white or beige. The tragus is half of the ear and in most animals it has a small black tip. The membranes of the broad wings are brownish.

The up to 10 ms long frequency-modulated calls drop from approximately 120-70 kHz to 26-29 kHz. Not distinguishable from the Lesser Mouse-eared Bat, but it can be distinguished from smaller Myotis species by the distinctly higher or lower frequencies and a visual size estimation of hunting animals.

Usually occurs at altitudes below 800 m, but in Bulgaria it has been established up to 2500 m (Stara mountain). Colonies are usually in areas with a high proportion of forest. The hunting grounds are characterized by ready access to the ground and to ground-dwelling arthropods. They hunt also over temporary sites, such as meadows, pastures and fields that are freshly mown, grazed or harvested. The Greater Mouse-eared Bat is a regionally migrating species with movement between summer, swarming and winter sites of distances of usually 50-100 km. The hunting grounds usually lie in a 5-15 km zone around the roost.

In Central Europe, the reproductive colonies dwell mainly in large roof spaces, and occasionally in cellars and large bridges, in the Mediterranean area – mostly in caves. Underground winter roosts are in caves, bunkers and rock storage tunnels but also in rock crevices.

Large clusters are formed in the summer roost, in the Mediterranean area often mixed with other species. Only a few males remain with nursery roosts. The colony sites are occupied from between the last days of March to the beginning of May, and vacated after the young are weaned beginning at the end of August. Central European nursery colonies comprise 50-1000 females, in the Mediterranean area they number up to 8,000 animals. From the middle of August, Greater Mouse-eared Bats swarm at caves, with peak activity in the later third of August. They also come here to mate. Mating usually occurs in roosts of males. The birth of an infant takes place between the end of May and beginning of June, in the Mediterranean as early as in the beginning of April.

The Greater Mouse-eared Bat often hunts at a low height. During close orientation the sense of smell probably plays a large role. Chafers and other large insects can also be pursued and taken in flight. Their common prey are ground-dwelling beetles (Carabus) followed by other other ground-dwelling arthropods such as centipedes, spiders and beetle larvae.

Endangered by building renovation, increasing habitat fragmentation and the use of environmental poisons. The increasing cave tourism is also a 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”.

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