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

摘要

Knowledge of the feeding ecology of a species at local level is fundamental to determine the relationship between the fluctuations in local marine resources and population dynamics of predators. In this study, we examined the diet of Ad,lie penguins (Pygoscelis adeliae) during the crSche stage at the Stranger Point colony, South Shetland Islands, Antarctica, over a 13-year period (2002/2003-2014/2015). Antarctic krill (Euphausia superba) was the dominant prey for Ad,lie penguins during the crSche period (contribution: 100% of occurrence and 99.7% by mass). The fish component in the diet represented a small proportion of the total prey (contribution: from 4 to 24% of occurrence but 0.15% by mass). A marked inter-annual variability in the mass of stomach contents, the krill size consumed and the proportion of juvenile krill was observed. Moreover, a possible recruitment event of krill was recorded. A negative relationship between the size of krill in the diet and breeding success was found, suggesting that population dynamics of krill also reflected changes in the local availability of this crustacean. This work is the first long-term study of dietary parameters of Ad,lie penguins for the Stranger Point colony.