Diet composition and foraging habitats of Adélie and gentoo penguins in three different stages of their annual cycle

JUARES, MA; SANTOS, MM; MENNUCCI, JA; CORIA, NR; MARIANO Y JELICICH, ROCÍO

MARINE BIOLOGY

SPRINGER

Lugar: Berlin; Año: 2016 vol. 163

0025-3162

Abstract We evaluated the diet of Adélie (Pygoscelisadeliae) and gentoo (P. papua) penguins at Stranger Pointcolony (25 de Mayo/King George Island) during differentstages of their annual cycle using the stable isotopemethod and the conventional dietary analyses (i.e. stomachcontents). Antarctic krill (Euphausia superba) dominatedthe diet of Adélie and gentoo penguins in all threestudied stages (pre-breeding, breeding and post-breeding).Nevertheless, only in gentoo penguins a shift in the dietwas evident from mainly krill during the breeding stage tomixed diet (i.e. krill and fish/squids) during the pre- andpost-breeding stages. Results from stable isotopes suggestthat Adélie penguins might be foraging in southern localitiescompared to their congener during the inter-breedingperiod. Moreover, Adélie penguins showed a large individualvariability in foraging habitat during the post-breedingstage. However, our model has predicted that both speciesexploited similar areas during the breeding season. Theresults obtained during the chick-rearing stage were comparedwith the stomach contents of both species obtainedduring the same season (2011/2012). Our findings providenew knowledge on the feeding ecology and foraging habitatsof pygoscelid penguins. They confirm the importanceof Antarctic krill during the annual cycle and improve theunderstanding of life strategies and predator?prey interactionsessentially out of the reproductive period, in whichthe information is very limited. These results can help toestablish new management strategies, particularly consideringthe potential overlap between predators and fisheries.