Effects of sea-ice persistence on the diet of Adélie penguin (Pygoscelis adeliae) chicks and the trophic differences between chicks and adults in the Ross Sea, Antarctica

In Antarctica, prey availability for the mesopredator Adélie penguin, Pygoscelis adeliae, depends on sea-ice dynamics. By affecting cycles of sea-ice formation and melt, climate change could thus affect penguin diet and recruitment. In the light of climate change, this raises concerns about the fat...

Full description

Bibliographic Details
Published in:Biology
Main Authors: Deborah Maccapan, Giulio Careddu, Edoardo Calizza, Simona Sporta Caputi, Loreto Rossi, Maria Letizia Costantini
Other Authors: Maccapan, Deborah, Careddu, Giulio, Calizza, Edoardo, SPORTA CAPUTI, Simona, Rossi, Loreto, Costantini, Maria Letizia
Format: Article in Journal/Newspaper
Language:English
Published: MDPI 2023
Subjects:
Online Access:https://hdl.handle.net/11573/1679535
https://doi.org/10.3390/biology12050708
Description
Summary:In Antarctica, prey availability for the mesopredator Adélie penguin, Pygoscelis adeliae, depends on sea-ice dynamics. By affecting cycles of sea-ice formation and melt, climate change could thus affect penguin diet and recruitment. In the light of climate change, this raises concerns about the fate of this dominant endemic species, which plays a key role in the Antarctic food web. However, few quantitative studies measuring the effects of sea-ice persistence on the diet of penguin chicks have yet been conducted. The purpose of this study was to fill this gap by comparing penguin diets across four penguin colonies in the Ross Sea and evaluating latitudinal and interannual variation linked to different sea-ice persistence. Diet was evaluated by analysing the δ13C and δ15N values of penguin guano, and sea-ice persistence by means of satellite images. Isotopic values indicate that penguins consumed more krill in colonies with longer sea-ice persistence. In these colonies, the δ13C values of chicks were lower and closer to the pelagic chain than those of adults, suggesting that the latter apparently catch prey inshore for self-feeding and offshore for their chicks. The results indicate that sea-ice persistence is among the principal factors that influence the spatiotemporal variability of the penguins’ diet.