Foraging ecology of the horseshoe bat, Rhinolophus megaphyllus (Rhinolophidae), in eastern Australia

Abstract

The foraging ecology of the eastern horseshoe bat, Rhinolophus megaphyllus, was examined at five sites spread along 2100 km of its Australian distribution in coastal Queensland. Foraging strategy and prey-capture behaviour of light-tagged bats were similar across sites. Bats were observed foraging during continuous flight at all sites, whereas perch hunting was observed (rarely) at only one site. Bats captured insects by aerial hawking, with a single record of gleaning. In rainforest bats spent most time close to vegetation whereas openings were favoured in open forest/woodland. Only flying insects were captured and, although a wide range of taxa was taken, Lepidoptera (all sites) and Coleoptera (all sites except one) were the primary prey. Occurrence in faeces of Lepidoptera, Coleoptera, and other taxa combined, varied across sites and across seasons, but there was no three-way interaction between taxon, site and season. Comparison of insect taxa in faeces with those captured in a light-trap set at foraging grounds indicated that insects were selectively captured by R. megaphyllus. The foraging ecology of R. megaphyllus is similar to that of other horseshoe bats in its relative stability across a large geographic range. Although the species is currently not of conservation concern in Australia, aspects of its foraging ecology suggest that it may become regionally threatened in areas with high levels of vegetation clearance.