DescriptionLarge-scale declines in arthropod diversity and abundance urges the need to understand its consequences on trophic interactions. Because monitoring diets is difficult in small predators with diverse diets, we aimed to test the quantitative accuracy of DNA-metabarcoding of faeces through understanding(digestive) biases and validation with recorded diets. In 39 camera sessions in the forests of Drenthe,The Netherlands, we documented food items delivered to nestling Pied Flycatchers by their parents. Faeces of these nestlings were metabarcoded with COI-barcoding primers, customized to avoid flycatcher DNA. We found that proportions of arthropod orders fed to nestlings on camera footage (approximated prey biomass) strongly correlated with the proportions in barcode reads. Within Lepidoptera, Diptera and Coleoptera, barcodes and camera records retrieved the same common families. The large similarity in gizzards and lower intestines of eight males, victims of competitors for nest boxes, established limited digestive bias. Our data show that DNA-metabarcoding can be used as a quantitative tool for diets of insectivorous birds. We applied this method to a few hundred adults in Drenthe throughout the nesting period. Adult diet was very different from nestling diet, also during provisioning. We discuss prey communities and the resolution of metabarcoding at lower taxonomic levels.
|Event title||Netherlands Annual Ecology Meeting 2020|
|Organiser||Netherlands Ecological Research Network (NERN)|
|Degree of Recognition||International|