South-Eastern Europe, Crete, Cyprus, Asia Minor along the Caucasus to Pakistan, in the Near and Middle East and the Arabian Peninsulа. Also North Africa, savannah landscapes south of Sahara to South Africa. In Bulgaria occurs in all the low parts of the country. The species is numerous in Southern Bulgaria.
A medium-sized horseshoe bat with fur tinged pale brown to sand or yellowish coloured. The ventral side is a little paler. The connecting process is pointed and straight, not curved downwards. The sella tip is narrowed with shouldered sides towards the tip. The first phalanx of the fourth finger is more than half the length of the second phalanx.
The long constant-frequency calls are at 92-98 kHz in roosting animals. There is no overlap with the frequency used by the other European horseshoe bats.
Usually occurs in lower altitudes. Hunts in scrub, in low-growing hornbeam and oak forests. In Bulgaria prefers places rich in vegetation, rarely karst areas. Summer and winter roosts are close to each other. Hunting grounds are also close.
They inhabit caves all year round. Single animals can be found in mines and other underground roosts. Hibernation temperatures are usually between 13.8 and 17°C.
Blasius`s Horseshoe Bat forms nursery colonies of 30-500 animals. In a South Bulgarian cave the were up to 3,000 animals in some years. Numerous adult males occur in nursery roosts. In the nursery roosts before the time of birth, males and non-reproducing females can constitute up to a third of the animals.
In roost, the bats form single species colonies, the clusters are mixed with the Mediterranean, Mehely`s and Greater Horseshoe Bats, Greater and Lesser Mouse-eared Bats and Schreiber`s Bent-winget and Long-fingered Bats.
In South Bulgaria, birth takes place in late June, with only one young per female. In the middle of September some lactating females can still be found in the Rhodope mountains, indicating very late birth date in some animals.
Mating takes place partly in September. Males hang in caves in front of a female and display with flapping wings and court her, before mating occurs.
Hunts only in flight, circling around shrubs and hedges. They search systematically. Their flight is agile and they can catch prey close to vegetation or pick prey from the ground. Blasius`s Horseshoe Bat feeds mostly on moths.
In South-Eastern Bulgaria and in Greece there are still stable populations. But the others European populations are heavily threatened. In Israel the species has been almost completely exterminated by eradication campaigns against the Egyptian Fruit Bat using cave fumigation.
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”.