Env Exp Biol (2010) 8: 93–96

The parti-coloured bat Vespertilio murinus in Rīga (Latvia) during autumn and winter

Abstract

The parti-coloured bat is a migratory species for which long-distance movements have been documented from North-eastern to Central Europe. Records in autumn and winter suggest that some populations in northern Europe may be sedentary. During the mating period, male parti-coloured bats can be observed in cities, emitting loud and audible advertisement calls near high buildings. The aim of this study was to determine whether parti-coloured bats currently mate and hibernate in Rīga, the capital of Latvia. High buildings in 13 districts were visited to locate displaying males. Display activity was studied at one site by means of acoustic recording. Displaying males were observed in two districts from late September until early November. Records of parti-coloured bats in December and April confirm that this species hibernates in Rīga. The parti-coloured bats most likely arrive from distant locations, since this species is considered to be rare in Rīga during the breeding period.