Myotis blythii (oxygnathus)

Myotis blythii (oxygnathus)
Myotis blythii (oxygnathus)
Lesser mouse eared bat

In Europe it is distributed throughout the Mediterranean area, northwards to Central France, Switzerland (close to the German border), Czech Republic, Slovakia and Ukraine. Widely distributed in Asia Minor, also on Cyprus and Crete. Eastwards – in the Caucasus, the Near East and to Central Asia.1 Bulgaria – the lower parts of the country, but it is established in Stara mountain (1,400 m) and Pirin mountains (2,500 m).

A large bat, very similar to the Greater Mouse-eared Bat. The dorsal surface has a brownish tinge, the ventral side is pale grey-white, usually somewhat paler than that of the Greater Mouse-eared Bat. The face is somewhat shorter than that of the Greater Mouse-eared Bat, the ears somewhat narrower and shorter, and the front edge of the ears somewhat less convex. The tragus is pale coloured to the tip, without a dark spot at the end.

The calls strongly resemble those of the Greater Mouse-eared Bat.

In general, warm open landscapes, extensively used meadowland, damp meadows, pasture, karst areas, steppe landscapes and extensively used agricultural areas. То a large extent avoids large closed forest areas, in which the Greater Mouse-eared Bat dominates. In Bulgaria they can be found in the karst areas. Summer and winter roosts are usually only 15 km apart from each other, rarely more. The average distance between the hunting grounds and roosts reaches 4 – 7 km with the longest distances to some hunting grounds being 9 – 25 km.

Summer and nursery roosts in the northern distribution area (Switzerland and Austria) are in attics; in the Mediterranean area they are almost exclusively in large caves and other underground sites. Males occupy caves and bunkers all year round, in the summer also fissures on bridges or buildings. Winter roosts in caves or other underground sites.

Roosts in caves are nearly always occupied with other bat species, often mixed clusters are formed. An almost pure cluster of Lesser mouse-eared Bats in a Bulgarian cave comprises of approximately 8,000 animals. No males occur in the nursery colonies but during the maternity period they are quite often found in the vicinity of the roost. Clusters of several hundred animals are found in winter.

The hunting flight is made at 1 – 2 m height above the ground. When discovering prey, the Lesser Mouse-eared Bat reacts very agilely and can take the prey in flight or from grass stalks. The food consists of a large proportion of bush-crickets, crane flies, chafers, grasshoppers, ground beetles and mole crickets.

Loss of habitat is due to intensive ploughing of meadows and reclamation of steppe areas in Hungary, Romania, north-east Bulgaria and Ukraine, as well as the abandonment of the use of extensive hay meadows, causes population collapse. Tourism is also a problem in the Mediterranean area.


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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