Dietary Composition, Resource Partitioning and Trophic Niche Overlap in Three Forest Foliage-Gleaning Bats in Central Europe

Abstract

A diverse syntopic bat community was studied in Central Europe. The study was primarily aimed at forest bats utilizing a foliage-gleaning foraging strategy (Myotis nattereri, M. bechsteinii and Plecotus auritus). The results indicated the foliage-gleaning foraging strategy and the effective resource partitioning. Once a certain diet item comprises an important food resource for one bat species, it is usually exploited much less by the other two bat species, and despite important seasonal dietary changes this pattern lasts throughout the entire season. Dietary composition varies more among the entire guild of forest foliage-gleaning bats than it does between these species and their morphological siblings or evolutionarily related species (e.g., Plecotus auritus vs. P. austriacus or Barbastella barbastellus, Myotis nattereri vs. M. emarginatus). The results are not fully consistent with the predictions of sensory ecology, which presume that bats with longer ears feed more frequently on prey that generates sound. The results do not support the hypothesis that rare bats exploit a narrower range of prey. The relatively rare M. bechsteinii has a wider trophic niche, whereas the more common P. auritus exploits a narrower range of prey. Comparison of dietary composition and morphological and echolocation parameters indicates that larger species feed on harder prey, species with longer ears are moth-eating specialists and species with a higher call intensity exploit small dipterans, probably in uncluttered habitats.