Using faecal DNA metabarcoding to determine the diet of the long-tailed bat, Chalinolobus tuberculatus

Abstract

Dietary analysis of nocturnal aerial insectivores such as bats is not possible by direct visual observation of predation, therefore diet is traditionally determined by analysing dietary remains in scats. Analysing DNA in scats through metabarcoding can reveal dietary items not preserved in faeces but also resolve dietary preferences to species level. DNA metabarcoding analysis of scats collected from six individual long-tailed bats (Chalinolobus tuberculatus) from Whirinaki Forest Park revealed a predominance of aquatic insects (Ephemeroptera and Trichoptera) and small-bodied moths (Lepidoptera). This contrasts with earlier studies of faecal remains in this species which revealed a strong preference for Dipterans and Coleopterans. The use of DNA metabarcoding may provide a better understanding of diets, as soft-bodied insects can be detected even when not apparent in physical examinations of scat, and thus will allow for more robust comparison of differences in diets between populations and seasons. The application of DNA metabarcoding is a simple but high-resolution tool to allow further study on dietary preference in this endangered species.