PDFDOI: https://doi.org/10.2478/vzoo-2014-0063
We analysed the sex and age composition of a large colony of Nyctalus noctula (605 specimens), wintering in Kyiv, Ukraine. Age was identifi ed in 113 individuals using the method of counting growth layer groups in dentine. Males contained ca. 70 % both in the colony and in the sample of animals with the estimated ages. Males and females of all ages were in good body condition. Th ere were bats from 0+ to 7+ years old in the sample. In males, 0+ age class was represented by 38 %; 1+ class, by 20 % of individuals. In females, 0+ and 1+ year old individuals were found in similar numbers: 29 % and 32 % correspondingly. Th e observed sex ratio and proportions of males and females across age classes cannot be explained only by demography. Th e data are interpreted in terms of migratory behaviour and mating strategy of the species: the unusual female age structure is possibly due to age-specifi c preferences in wintering habitat selection and search for potential mating partners.