Demographic models and IPCC climate projections predict the decline of an emperor penguin population

• Published in: Proceedings of the National Academy of Sciences
• Main Authors: Jenouvrier, Stéphanie, Caswell, Hal, Barbraud, Christophe, Holland, Marika, Stroeved, Julienne, Weimerskirch, Henri
• Other Authors: Centre d'Études Biologiques de Chizé (CEBC), Centre National de la Recherche Scientifique (CNRS), Biology Department (WHOI), Woods Hole Oceanographic Institution (WHOI), Oceanography Section, National Center for Atmospheric Research Boulder (NCAR), National Snow and Ice Data Center (NSIDC), University of Colorado Boulder
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2009
• Subjects: bird populations; climate change; quasi-extinction; sea ice; stochastic matrix population models; [SDE.BE]Environmental Sciences/Biodiversity and Ecology; [SDE.ES]Environmental Sciences/Environmental and Society; [SDE.MCG]Environmental Sciences/Global Changes; Antarctic; Terre Adélie; Terre-Adélie; Antarc*; Antarctica; Aptenodytes forsteri; Emperor penguins; Sea ice
• Online Access: https://hal.science/hal-00360498; https://doi.org/10.1073/pnas.0812940106

International audience Studies have reported important effects of recent climate change on Antarctic species, but there has been to our knowledge no attempt to explicitly link those results to forecasted population responses to climate change. Antarctic sea ice extent (SIE) is projected to shrink as concentrations of atmospheric greenhouse gases (GHGs) increase, and emperor penguins (Aptenodytes forsteri) are extremely sensitive to these changes because they use sea ice as a breeding, foraging and molting habitat. We project emperor penguin population responses to future sea ice changes, using a stochastic population model that combines a unique long-term demographic dataset (1962-2005) from a colony in Terre Adélie, Antarctica and projections of SIE from General Circulation Models (GCM) of Earth's climate included in the most recent Intergovernmental Panel on Climate Change (IPCC) assessment report. We show that the increased frequency of warm events associated with projected decreases in SIE will reduce the population viability. The probability of quasi-extinction (a decline of 95% or more) is at least 36% by 2100. The median population size is projected to decline from approximately 6,000 to approximately 400 breeding pairs over this period. To avoid extinction, emperor penguins will have to adapt, migrate or change the timing of their growth stages. However, given the future projected increases in GHGs and its effect on Antarctic climate, evolution or migration seem unlikely for such long lived species at the remote southern end of the Earth.