Importance of night roosts for bat conservation:roosting behaviour of the lesser horseshoe bat Rhinolophus hipposideros

摘要

Safeguarding day roosts is of key importance in bat conservation. However, little emphasis has been placed on the conservation of night roosts, although these may act as refuges close to foraging grounds. We studied the roosting behaviour of the lesser horseshoe bat Rhinolophus hipposideros, a species that has declined over large areas of Europe, and radio-tracked 54 bats from 3 maternity roosts in contrasting landscapes in Britain. The bats exhibited multimodal patterns of overnight activity (mean ind.–1: 2.1 to 4.5 night roosting bouts). More than 75% of bats used night roosts away from the maternity roost, typically in buildings. Up to 5 different night roosts were used by individual bats, with the number of night roosts correlated with home range and core area. Night roosts were significantly nearer to core foraging areas than were maternity roosts, with 64 to 86% contained within core nuclei. Multimodal activity patterns and frequent use of night roosts are important aspects of R. hipposideros behaviour that need to be considered in management strategies. We postulate that minimisation of distance to feeding sites may be the primary function of the night roosts, with roosts being used for resting and digestion between foraging bouts. Night roosts are therefore an integral part of core foraging areas and require protection.