Eptesicus serotinus

Eptesicus serotinus
Serotine nat

Throughout Central and South Europe. Widely distributed in the northern Mediterranean region. The Near East and the Caucasus to Central Asia. In North Africa and the Canary Islands.1

A large bat with a broad muzzle. The ears are fairly long with rounded tips. The face is black-brown. The fur is long and the dorsal side is dark brown with yellow-golden tips. The ventral side is poorly demarcated from the dorsal, and it is paler brown to yellowish-brown. The wings are broad.

The FM calls are up to 23 ms long with a QCF end part at 23 – 27 kHz. Long QCF calls have a peak frequency of 22 – 24 kHz and FM-QCF calls are with variable peaks between 23 – 44 kHz. The calls are audible with a detector from 30 – 40 m.

This species occurs in different habitats – open areas with groups of trees or in the city. Their hunting grounds are agricultural areas, parks, traditional orchards, pastures, forest edges, water bodies and the center of the cities. Sedentary species – small distance between the summer and winter roosts. They have no more than 10 hunting grounds which are situated at 5 – 12 km from the roost.

Roosts are in buildings – crevices and unused roof structures. Also this species uses rock crevices and sometimes tree holes.

The copulation occurs during fall and spring. Nursery colonies are formed in May and they comprise of 10 – 60 adult females. Pregnancy is 6 – 8 weeks long. The young are born in the second half of June. After two months they are independent. Life expectancy is 19 years.

The flight is slow, this species makes circles around individual trees or in open areas. Serotine bats can also pick the prey directly from the ground. Their food consists of beetles, moths and Diptera.

Building renovation and use of pesticides. Loss of hunting grounds like pastures and orchards will lower the food resources.

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”.