King penguin population threatened by Southern Ocean warming

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 105; no. 7; pp. 2493 - 2497
• Main Authors: Le Bohec, Céline, Durant, Joël M, Gauthier-Clerc, Michel, Stenseth, Nils C, Park, Young-Hyang, Pradel, Roger, Grémillet, David, Gendner, Jean-Paul, Le Maho, Yvon
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences 19.02.2008; National Acad Sciences
• Subjects: adults; Aging - physiology; Animal breeding; Animals; Antarctic region; Aptenodytes patagonicus; Aquatic birds; Aviculture; Binomial Distribution; Biodiversity; Biodiversity and Ecology; Biological Sciences; Birds; Breeding; Breeding of animals; Breeding success; climate; Climate change; Climate effects; Climate models; dynamic models; El Nino; Environmental impact; Environmental Sciences; extinction; Food availability; food chain; Foraging; Global Changes; Global warming; Greenhouse Effect; ice; Life Sciences; Marine; Marine ecosystems; Models, Biological; Ocean currents; Ocean warming; Oceans; Oceans and Seas; Pack ice; Parametric models; Penguins; Population Dynamics; Populations and Evolution; prediction; risk; Sea birds; Sea surface temperature; seabirds; Southern Oscillation; Species extinction; Spheniscidae - physiology; surface water temperature; Survival; Survival analysis; Temperature; Time Factors; PS, Antarctic Ocean; Antarctic region; unbanded penguins; time lag; seabirds; climate changes
• ISSN: 0027-8424; 1091-6490; 1091-6490
• DOI: 10.1073/pnas.0712031105

Seabirds are sensitive indicators of changes in marine ecosystems and might integrate and/or amplify the effects of climate forcing on lower levels in food chains. Current knowledge on the impact of climate changes on penguins is primarily based on Antarctic birds identified by using flipper bands. Although flipper bands have helped to answer many questions about penguin biology, they were shown in some penguin species to have a detrimental effect. Here, we present for a Subantarctic species, king penguin (Aptenodytes patagonicus), reliable results on the effect of climate on survival and breeding based on unbanded birds but instead marked by subcutaneous electronic tags. We show that warm events negatively affect both breeding success and adult survival of this seabird. However, the observed effect is complex because it affects penguins at several spatio/temporal levels. Breeding reveals an immediate response to forcing during warm phases of El Niño Southern Oscillation affecting food availability close to the colony. Conversely, adult survival decreases with a remote sea-surface temperature forcing (i.e., a 2-year lag warming taking place at the northern boundary of pack ice, their winter foraging place). We suggest that this time lag may be explained by the delay between the recruitment and abundance of their prey, adjusted to the particular 1-year breeding cycle of the king penguin. The derived population dynamic model suggests a 9% decline in adult survival for a 0.26°C warming. Our findings suggest that king penguin populations are at heavy extinction risk under the current global warming predictions.