Rhinolophus mehelyi

Rhinolophus mehelyi
Rhinolophus mehelyi
Rhinolophus mehelyi
Rhinolophus mehelyi

Distributed in a narrow band around the Mediterranean Sea from North-Western Africa across Portugal, Spain, the Balearics, southern France, Sardinia, Sicily and the Balkan Peninsula to Asia Minor. In Bulgaria – inĀ the lower parts of the country. Relatively rare species.

The largest of the three medium-sized horseshoe bats. The ventral side is pale, often almost white and is sharply delineated from the grey-brown dorsal fur. In most older animals there are dark circles of grey-brown hairs around the eyes, but these can occur in other species. The connecting process is usually bluntly rounded and extends beyond the tip of the sella. Seen from the front, the sella is wide at the tip, and seen from below it is parallel sided. The second phalanx of the fourth finger is more than twice as long as the first phalanx.

At rest the long constant-frequency part of the call is between 104 and 112 kHz. This Frequency range overlaps with those of Mediterranean and Lesser Horseshoe bats. But the Lesser Horseshoe Bat can be differentiated by sight on the basis of its small size. Frequencies of over 108 kHz almost certainly exclude the Mediterranean Horseshoe Bat.

Mehely`s Horseshoe Bat usually occurs at low altitudes of below 700 m and is dependent on cave-rich karst areas. Foraging territories include steppes, semi-steppes, meadows, pastures, arable land and savannah-like biotopes, as well as light cork and holm oak forests and olive groves. In Bulgaria it is found that where the Mediterranean horseshoe bat is encountered together with Mehely`s Horseshoe Bat, both species avoid open spaces. They often hunt over riparian forest habitats. Mehely`s Horseshoe Bat also prefer park-like woods.

Mehely`s Horseshoe Bat hunts at distances of up to 15 km from the roost; the average distance between hunting grounds and roosts was 3.3-8.2 km in Spain and 5.3 km in Bulgaria.

Summer and winter roosts are exclusively in caves, sometimes also in mines.

Nursery colonies comprise of 20-200, rarely up to 500 animals. In northern Bulgaria, nursery roosts with up to 5,000 adult animals were present, but this number is now greatly reduced. In the roost this species often mixes with Mediterranean Horseshoe bats and other cave species. In Bulgaria there are mixed hibernation groups with up to 10,000 medium-sized horseshoe batts. Only one young is born. In Bulgaria births occur in the first days of June or in the beginning of July. The high proportion of non-reproducing females indicates that sexual maturity is reached only in the second year. In Bulgaria mating takes place from the end of September.

The flight is manoeuvrable and it is very low over grass, often between grass stems. The hunting is carried out in the second half of the night, or during the whole night by pregnant animals. For this, animals hang on individual plants (common mulleins, high sunflowers, bushes) and scan the environment. Moths comprise over 90% of the prey animals, but seasonally crane flies and beetles play a significant role.

The rarest of the medium-sized horseshoe bats. This species is especially sensitive to the loss of insect-rich, extensively cultivated meadows and pastures and the decline in suitable open land habitats. This species has a very high susceptibility for disturbance in the roosts.

 

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”.