Rhinolophus blasii Peters, 1866
Conservation status: in Bulgaria: Vulnerable VU [A2c], BDA-II, III; International: IUCN-NT; BeC-II, III, BoC-II, HD-II, IV.
General distribution. Africa; Italy, Sicily, the Balkan peninsula; Israel, Jordan, Syria and Yemen; Cyprus; Turkey; Transcaucasia, Iran, Afganistan and Pakistan.
Distribution and abundance in Bulgaria. About 60 localities are found . In the southern parts of the country the species is comparatively ordinary and with a higher frequency of finding and abundance . The western and the central parts of the Prebalkan region and the line Veliko Tarnovo – Kotel – Primorsko outline part of the northern border of the range. The minimal estimate of the summer population is about 5 000 individuals. For the cave-loving species of bats, to which the Blasius' horseshoe bat belongs, a decrease of the numbers by 20-40% at the average was registered in the 1988-1992 period with respect to the 1955-1971 period .
Habitats. Karstic regions in the valleys and the hilly parts of the country. It is entirely linked to underground shelters: caves and mine galleries.
Biology. It forms colonies with numbers of several hundred to several thousand individuals, often together with the Mediterranean horseshoe bat (Rh. euryale) and Mehely's horseshoe bat (Rh. mehelyi). The maximum of birth givings is in the period 20 June –10 July. Wintering colonies are known only from the caves Ayna Ini and Samara (the village of Ribino, the Eastern Rhodopes), Parnitsite (the village of Bezhanovo) and Morovitsa (the village of Glozhene). It does not migrate but makes regular seasonal trips between the summer and the winter shelters.
Similar species. Mediterranean horseshoe bat (Rhinolophus euryale) and Mehely's horseshoe bat (Rhinolophus mehelyi).
Negative factors. Anthropogenic influence on the shelters: destruction or disturbance in them, placing doors and bars that prevent or hinder the access to them and lead to a change of the microclimate. Anthropogenic pressure on the hunting habitats and flight corridors, for example the destruction and the fragmentation of the natural deciduous forests.
Conservation measures taken. The species is protected according to the Biological Diversity Act, EUROBATS and all the other conventions (without CITES). Many of the underground shelters in Bulgaria fall within different categories of protected territories. The inclusion of the known shelters in the Natura 2000 network of protected zones is about to be effected.
Conservation measures needed. Protection of underground shelters. Working out detailed management plans for those that are declared protected territories. Studies for clarifying the "interim" (spring and autumn) copulative shelters and of concrete hunting habitats and flight corridors, so that they should also be protected. The negative effect of urbanization, in so far as the species avoids urbanized habitats. The complex conservation approach requires the preservation of the habitats within a radius of at least 5 km from the summer shelters. Continuation of the yearly monitoring in the significant underground shelters of bats .
References. 1. Benda et al., 2003; 2. Popov & Ivanova, 2002; 3. Beshkov, 1993; 4. Ivanova, 2005.
Authors: Vasil Popov, Teodora Ivanova