High trophic similarity in the sympatric North European trawling bat species Myotis daubentonii and Myotis dasycneme

Most European bat species are insectivorous and share foraging areas to some extent. Where similar species rely on similar resources in the same foraging habitat, they are likely to interact. This study addresses the trophic niche of the Northern European trawling bat species Myotis dasycneme (Boie, 1825) and Myotis daubentonii (Kuhl, 1817), occurring in the same habitat, and possible interactions or differences within their dietary behaviour. Dietary data of both species were analysed to draw conclusions on their ecology, possible dietary overlap, hints for coexistence mechanisms and community structure. In this study, M dasycneme and M. daubentonii fed mainly on Chironomidae (M dasycneme: 44.4%; M. daubentonii: 32.8%) and Trichoptera (M dasycneme: 20.4%; M daubentonii: 22.2%), showing a high trophic niche overlap and similar niche breadth. Nevertheless, there were differences in the diet of the two species concerning the predation of chironomids. Differences also occur regarding the prey types, referring to the terrestrial or aquatic life-cycle of prey groups. This could be evidence for different foraging habitats and a spatial segregation of both species. High resource abundance is also likely to allow the coexistence of both species within the same hunting habitat.