In Europe, the northernmost confirmed records are from southern Finland near 60°N. Occurs also in north-west Africa, Asia Minor and the Middle East eastwards to Iran and Afghanistan.1 In Bulgaria – in the low parts of the country.
The smallest European bat with dark brown dorsal side and a little paler yellow-brown ventral side. The face, ears and membranes are dark brown or black.
The calls are up to 10 ms long with peak frequencies of 41 – 48 kHz, shorter calls are with peak frequencies of 43 – 50 kHz. The frequencies below 42,5 kHz are within the overlap range of Nathusius’ Pipistrelle bat. The social calls are characteristic, usually comprising of 4 – 5 trills with end frequencies between 17 and 20 kHz.
This species is very flexible – can be seen in parks, gardens, in city centres, in villages, woodland and water areas. A sedentary species with seasonal flights between summer and winter roosts that are less than 100 km. Nursery roost are changed regularly. The hunting grounds are close to the roosts.
The summer and winter roosts are in tree holes, behind tree barks and in rock crevices. This species is extensively synanthropic and uses different parts of the buildings – under roofs and crevice-like spaces.
The copulation is in the fall, rarely during the spring. Adult males establish mating roosts into which they lure females with songs and specific flights. Nursery colonies are formed in April – May and they comprise of 50 – 100 animals. Females give birth to one young in the beginning of June. After three weeks they can fly and their mothers teach them how to hunt. After that they leave the colony. Young animals reach sexual maturity in the first autumn.
In Slovakia and particularly in Romania there are mass winter roosts in caves.
The flight is fast with a cutting motion 2 – 6 m above the ground. Common Pipistrelle bats hunt over rivers, under street lamps and in the outskirts of the forests. They catch small flying insects like mosquitoes, moths and Diptera.
Threatened by roost disturbance and pesticide use. The winter roosts in the Carpathian basin are threatened by cave tourism.
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”.