Reproductive performance and diving behaviour share a common sea-ice concentration optimum in Adélie penguins (Pygoscelis adeliae)

• Published in: Global Change Biology
• Main Authors: Le Guen, Camille, Kato, Akiko, Raymond, Ben, Barbraud, Christophe, Beaulieu, Michaël, Bost, Charles-André, Delord, Karine, MacIntosh, Andrew J J, Meyer, Xavier, Raclot, Thierry, Sumner, Michael, Takahashi, Akinori, Thiebot, Jean-Baptiste, Ropert-Coudert, Yan
• Other Authors: University of St Andrews. School of Biology, University of St Andrews. Pelagic Ecology Research Group
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2019
• Subjects: Antarctic; Sea ice; Pygoscelis adeliae; Diving activity; Foraging strategies; Breeding success; GE Environmental Sciences; QH301 Biology; NDAS; GE; QH301; Southern Ocean; The Antarctic; Antarc*; Antarctique*
• Online Access: https://hdl.handle.net/10023/18004; https://doi.org/10.1111/gcb.14377

This study was financially supported by the following institutions: the WWF-UK through R. Downie, the Japanese Mombukagakusho and the Japanese Society for the Promotion of Science, the Zone Atelier Antarctique et Subantarctique –LTER France of the CNRS. The Southern Ocean is currently experiencing major environmental changes, including in sea‐ice cover. Such changes strongly influence ecosystem structure and functioning and affect the survival and reproduction of predators such as seabirds. These effects are likely mediated by reduced availability of food resources. As such, seabirds are reliable eco‐indicators of environmental conditions in the Antarctic region. Here, based on 9 years of sea‐ice data, we found that the breeding success of Adélie penguins (Pygoscelis adeliae) reaches a peak at intermediate sea‐ice cover (ca. 20%). We further examined the effects of sea‐ice conditions on the foraging activity of penguins, measured at multiple scales from individual dives to foraging trips. Analysis of temporal organisation of dives, including fractal and bout analyses, revealed an increasingly consistent behaviour during years with extensive sea‐ice cover. The relationship between several dive parameters and sea‐ice cover in the foraging area appears to be quadratic. In years of low and high sea‐ice cover, individuals adjusted their diving effort by generally diving deeper, more frequently and by resting at the surface between dives for shorter periods of time than in years with intermediate sea‐ice cover. Our study therefore suggests that sea‐ice cover is likely to affect the reproductive performance of Adélie penguins through its effects on foraging behaviour, as breeding success and most diving parameters share a common optimum. Some years, however, deviated from this general trend, suggesting that other factors (e.g. precipitation during the breeding season) might sometimes become preponderant over the sea‐ice effects on breeding and foraging performance. Our study highlights the value of monitoring fitness ...