At-sea foraging behaviour in Hutton’s shearwater (Puffinus huttoni) as revealed by stable isotope analysis

Abstract

Stable isotope analysis of feathers can provide an indirect method to investigate the diet and foraging locations of birds during the time the feathers were growing. We used the isotopic composition of experimentally-induced feathers to investigate the foraging locations of the Hutton’s shearwater (Puffinus huttoni), an endangered seabird that is a breeding endemic to the Kaikōura region of New Zealand. The isotopic composition of feathers was first compared with potential prey items collected from the near-shore marine environment near the breeding colony.