Using molecular scatology to identify aquatic and terrestrial prey in the diet of a riparian predator, the Plumbeous Water Redstart Phoenicurus fuliginosa

Abstract

Capsule Molecular scatology can characterize predator diets by the identification of mixed and degraded prey fragments in predator faeces.Aims We evaluated whether a non-invasive, molecular technique was useful for identifying prey in the faecal samples of the Plumbeous Water Redstart Phoenicurus fuliginosa, which feeds in the riparian ecotone and, therefore, depends on prey from both terrestrial and aquatic sources.Methods Samples of intact faeces were collected in the riparian zone during 2010 to 2012 in Taiwan. A Bayesian model was used to delimit distinct species based on the phylogenetic species concept. Prey identities were determined using the Barcode of Life Data system.Results We examined 283 faecal samples and detected DNA in 190 using DNA barcodes. We identified 505 prey DNA sequences belonging to 108 distinct species. Beetles were detected in more samples (64 of 190) than any other taxon, and aquatic insects were found in 100 of 190 samples.Conclusion This molecular approach for identifying prey taxa in the faeces of a generalist predator provides information that improves our understanding of cross-ecosystem energy flow. To increase the percentage of sequences that can be identified, comprehensive, local reference sequences need to be added to the database.