Diet of Adélie penguins (Pygoscelis adeliae) at Stranger Point (25 de Mayo/King George Island, Antarctica) over a 13-year period (2003-2015).

JUÁRES M.; CASAUX R,; CORBALAN A.; BLANCO G.; PEREIRA A.; PERCHIVALE P.; CORIA N.; SANTOS M.

POLAR BIOLOGY

SPRINGER

Lugar: Berlin; Año: 2018 vol. 41 p. 303 - 311

0722-4060

AbstractA detailed knowledge of species diet can help us to interpret its ecological role, toidentify the driving factors of their population trends and to detect marineresources that need protection. In this study, through stomach content analysis we examined the dietduring the crèche stage of Adélie penguins (Pygoscelisadeliae) at Stranger Point colony (South Shetland Islands) over a 13 yearperiod (2002/2003 ? 2014/2015). Although stomach content analysis is amethodology that has some limitations, the study of the diet composition andthe feeding behaviour can provide some evidence of changes in the availability,quality and quantity of food resource in the vicinity of their reproductivecolony. Our findings confirm the large dependence of Adélie penguins byAntarctic krill (Euphausia superba)during the chick rearing period (contribution: 100 % of occurrence and >99.7 % by mass) and they suggest that fish could be an important prey forself-maintenance of the adult breeders (contribution: from 4 % to 24 % ofoccurrence but < 0.15 % by mass). Also, from the krill length consumed wasinferred some changes in local availability (a significant negativerelationship between the mean krill lengths and the breeding success wasevidenced) and a possible recruitment event of krill (during 2011/2012 a higherfrequency of one-year-old krill was recorded). Knowledge of the feeding ecologyof a species at a local level is fundamental to determine the relationshipbetween the fluctuations in local marine resources and population dynamics ofpredator.