The diet of post-breeding Antarctic shags Phalacrocorax bransfieldensis at the Danco Coast, Antarctic Peninsula

CASAUX, R.; BARONI, A.; RAMÓN, A.; BERTOLIN, M.; DI PRINZIO, C.Y.

ANTARCTIC SCIENCE

Año: 2009 p. 221 - 227

0954-1020

The diet of post-breeding Antarctic shags Phalacrocorax bransfieldensis wasinvestigated at four colonies at the Danco Coast, Antarctic Peninsula, by the analysis of 399 pellets (regurgitated casts) collected during February-March 1998 and 2000.Overall, demersal-benthic fish were the most frequent and important prey at all thecolonies sampled, followed by octopods and gastropods. Among fish, Nototheniacoriiceps and Gobionotothen gibberifrons were the main prey in all of the samplingsites in both seasons. The composition of the diet of post-breeding shags differed fromthat observed in the previous breeding season. Post-breeders preyed on the same fishspecies consumed by breeders, although in different proportions and on largerspecimens. The information provided here differs from that reported for post-breedingindividuals belonging to other shag species and also for post-breeding Antarctic shags.Our results, as well as the differences with previous studies, are discussed in relation todifferences in prey availability among localities and to the use of alternative foraginggrounds at the end of the breeding period.