Multi‐marker DNA metabarcoding reveals spatial and sexual variation in the diet of a scarce woodland bird

Abstract

Avian diet can be affected by site‐specific variables, such as habitat, as well as intrinsic factors such as sex. This can lead to dietary niche separation, which reduces competition between individuals, as well as impacting how well avian species can adapt to environmental variation. Estimating dietary niche separation is challenging, due largely to difficulties in accurately identifying food taxa consumed. Consequently, there is limited knowledge of the diets of woodland bird species, many of which are undergoing serious population declines. Here, we show the effectiveness of multi‐marker fecal metabarcoding to provide in‐depth dietary analysis of a declining passerine in the UK, the Hawfinch (Coccothraustes coccothraustes). We collected fecal samples from (n = 262) UK Hawfinches prior to, and during, the breeding seasons in 2016–2019. We detected 49 and 90 plant and invertebrate taxa, respectively. We found Hawfinch diet varied spatially, as well as between sexes, indicating broad dietary plasticity and the ability of Hawfinches to utilize multiple resources within their foraging environments.

DNA metabarcoding revealed how time and space do matter -sex does not- in the dietary variation of the endangered Dupont’s Lark

“…Spatial dietary differences of Dupont’s Lark were observed at different scales, probably reflecting dietary plasticity in response to variations in prey availability [66, 67]. At a macro-spatial scale, the diet of Dupont’s Lark varied between Spain and Morocco, with greater frequency of grasshoppers (Acrididae, Orthoptera) in the diet of African birds.…”

“…Sexual dietary differences have already been described for other bird species, including generalist medium-sized passerines such as the Black Wheatear ( Oenanthe leucura [16] or the Hawfinch ( Coccothraustes coccothraustes [67]). In contrast to our predictions, we revealed a high overlap between sexes in the diet of Dupont’s Lark during the breeding season, suggesting that foraging behavior and nutritional requirements are probably equivalents in both sexes.…”