Predator–prey interactions in the Arctic: <scp>DNA</scp> metabarcoding reveals that nestling diet of snow buntings reflects arthropod seasonality

Tundra arthropods are of considerable ecological importance as a seasonal food source for many arctic-breeding birds. Dietary composition and preferences rarely known, complicating assessments interactions in changing environment. In our field study, we investigated the nestling diet snow buntings (Plectrophenax nivalis (L., 1758)) breeding Svalbard. We collected fecal samples from 8-day-old nestlings assessed dietary by DNA metabarcoding. Simultaneously, availability potential prey was measured pitfall trapping. Molecular analyses feces identified 31 arthropod taxa diet, whose proportions changed throughout brood-rearing period. Changes matched varying abundances emergence patterns tundra community. Snow provisioned their offspring mainly with Diptera (true flies) based on both presence/absence relative read abundance items. At beginning season June, Chironomidae (nonbiting midges) scathophagid fly Scathophaga furcata (Say, 1823) dominated whereas muscid Spilogona dorsata (Zetterstedt, 1845) later July. When accounted availability, flies were selected positively among most often taxa. Our study demonstrates role bunting generalist predator highlights metabarcoding noninvasive technique high taxonomical precision if sufficient DNA-sequence libraries available.