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

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.

Little penguin (Eudyptula minor) diet at three breeding colonies in New Zealand

At-sea shifts in food quality and availability can affect populations of marine birds; however, it is difficult to evaluate the impacts of changes in prey composition and availability without some baseline information on diet composition. The little penguin (Eudyptula minor) is a common inshore-feeding seabird in New Zealand and Australia. To date, only two dietary studies have been undertaken on the little penguin in New Zeaalnd, at two widely separated locations.