Using faecal metabarcoding to examine consumption of crop pests and beneficial arthropods by avian insectivores

Generalist insectivorous birds can provide ecosystem services in agricultural landscapes by consuming arthropod pests, or they can provide disservices when they consume beneficial arthropods. To examine bird impacts on arthropod communities, including pest control services, we need to know which arthropods birds commonly consume. Faecal metabarcoding is an emerging technique that can be used to identify prey from faecal samples, often to the species level. We used faecal metabarcoding to study bird diets in a largely agricultural landscape in Illinois, USA. While previous studies have used Faecal metabarcoding to compare bird diets among species or among capture sites, we analysed samples from multiple species within a community at replicate sites. We collected faecal samples during the summer of 2017 from birds that inhabit the ecotone between soybean fields and grasslands, and likely forage in both habitats. We collected and sequenced DNA from 132 faecal samples from 25 bird species captured at six sites.