Abundance and community structure of bats (Chiroptera: Vespertilionidae) hibernating in artificial caves of Samarskaya Luka

Abstract

The structure of hibernating bat communities has been studied in eight artificial caves of Samarskaya Luka differing in size and layout. Three types of the relative abundance distribution (RAD) of species in these communities have been revealed. Conditions for hibernation are most favorable in large caves with a stable microclimate, where the abundance of bats is high, the Shannon index has the peak values, and variation in the index of species evenness is the lowest. In such caves, RAD fits the broken-stick and log-series models. Variation in diversity indices reaches the highest level in shallow adits with a changeable microclimate, where RAD fits the geometric series model. The abundance, diversity, and structure of communities depend mainly on cave size and the presence of absence of drafts and, to a lesser extent, on ambient temperature, availability of microshelters, and the type of landscape surrounding the cave. Anthropogenic factors have a weak effect only on the abundance of individual species (M. nattereri, M. daubentonii, M. dasycneme, and E. nilssonii) but not on the overall diversity of bat communities.