PRELIMINARY INFORMATION ON THE DIET OF THE IMPERIAL SHAG Phalacrocorax atriceps BREEDING ON ELEPHANT ISLAND, ANTARCTICA

Abstract

e aim of the study was to describe prey items in the diet of Imperial Shag through pellets analysis. e collection of pellets occurred in the breeding site during the austral summer of 2011/12 in Stinker Point, Elephant Island. A total of 34 pellets of Imperial Shag were analyzed and their frequency of occurrence was calculated. Fish remains were found in all pellets. Two families of demersal-benthic sh were identi ed through otoliths: Harpagiferidae and Nototheniidae. Nematodes occurred frequently. Other invertebrates such as molluscs and polychaetes occurred occasionally, so as vegetable matter (algae) and stones. ese items are probably from stomach contents of ingested sh or were accidentally ingested by the bird while building the nest. Our preliminary analysis showed that Imperial Shags breeding on Elephant Island have a similar diet composition to other shag species which breed in the sub-Antarctic islands and in the Antarctic Peninsula, with some items absent. However, further analysis will present more concrete data on the mass, volume and taxonomic species level of each item.