Arjun Kannan, Subbaiah Thalavaipandi, Deven Mehta, A. Saravanan, M. B. Prashanth, Thyagarajan Ganesh

Acta Ornithologica | June 14, 2023

Studies on the diet composition of bird species provide valuable insights on their habitat use, trophic interactions and prey selection. Prey abundance can drive movements of raptors in their wintering grounds. But such links have been difficult to establish due to the lack of dietary information for most raptor species. Estimating the wintering diet of raptors is a challenge that requires extensive fieldwork across a large geographical area which is often not possible. The methods used in breeding sites such as nest observations are not available in the non-breeding regions. Recently, several studies have demonstrated the use of web-sourced photographs as a tool for understanding the diet of raptors and also the need for combining multiple approaches to get a comprehensive overview of diet. In this study, we use a novel approach by using web-sourced photographs and pellets to estimate the variations in the diet of Montagu’s Harrier Circus pygargus, a species in decline, across its wintering range in India.