Molecular analysis of swab samples reveals the seabird diet of invasive Barn Owls in Hawaii

On Kauai island and neighboring Lehua (Hawaii, USA), invasive Barn Owls (Tyto alba) predate native seabirds, but difficult terrain in these regions and the cryptic nature of owl predation make traditional monitoring of predation quite challenging. Using metabarcoding to assess the diets of Barn Owls collected as part of existing removal efforts we detected six seabird species (including two ESA-listed species) in 20 percent of sampled owls - 10X the rate of predation detected based on necropsies. This case study illustrates the potential for genomic tools to change our understanding of ecological systems, with potentially important conservation implications.