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

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 ≈6,000 to ≈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.

[1]  J. Burton,et al.  Birds and climate change , 1995 .

[2]  W. R. Fraser,et al.  Effects of sea-ice extent and krill or salp dominance on the Antarctic food web , 1997, Nature.

[3]  B. Sæther,et al.  AVIAN LIFE HISTORY VARIATION AND CONTRIBUTION OF DEMOGRAPHIC TRAITS TO THE POPULATION GROWTH RATE , 2000 .

[4]  S. Rodionov.  A sequential algorithm for testing climate regime shifts , 2004 .

[5]  S. Solomon.  The Physical Science Basis : Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change , 2007 .

[6]  H. Weimerskirch,et al.  Antarctic birds breed later in response to climate change. , 2006, Proceedings of the National Academy of Sciences of the United States of America.

[7]  Vincent R. Gray.  Climate Change 2007: The Physical Science Basis Summary for Policymakers , 2007 .

[8]  M. Holland,et al.  Twentieth century simulation of the southern hemisphere climate in coupled models. Part II: sea ice conditions and variability , 2006 .

[9]  P. Lundberg,et al.  From climate change to population change: the need to consider annual life cycles , 2006 .

[10]  Marcel E Visser,et al.  Keeping up with a warming world; assessing the rate of adaptation to climate change , 2008, Proceedings of the Royal Society B: Biological Sciences.

[11]  H. Goosse,et al.  Analysis of the projected regional sea-ice changes in the Southern Ocean during the twenty-first century , 2007 .

[12]  E. Murphy,et al.  Environmental Change and Antarctic Seabird Populations , 2002, Science.

[13]  W. Sutherland,et al.  Climate Influences on avian population dynamics , 2004 .

[14]  P. Ponganis,et al.  Trends in western Ross Sea emperor penguin chick abundances and their relationships to climate , 2007, Antarctic Science.

[15]  J. Copas.  Plotting p against x , 1983 .

[16]  P. Jouventin.  Mortality parameters in Emperor penguins Aptenodytes forsteri , 1975 .

[17]  D. Réale,et al.  Keeping Pace with Fast Climate Change: Can Arctic Life Count on Evolution?1 , 2004, Integrative and comparative biology.

[18]  N. Stenseth,et al.  King penguin population threatened by Southern Ocean warming , 2008, Proceedings of the National Academy of Sciences.

[19]  Bernard Cazelles,et al.  Modelling population dynamics of seabirds: importance of the effects of climate fluctuations on breeding proportions , 2005 .

[20]  C. Both,et al.  Global Climate Change Leads to Mistimed Avian Reproduction , 2004 .

[21]  R. McCleery,et al.  Adaptive Phenotypic Plasticity in Response to Climate Change in a Wild Bird Population , 2008, Science.

[22]  M. Harris,et al.  The Biology of Penguins , 1976 .

[23]  O. Phillips,et al.  Extinction risk from climate change , 2004, Nature.

[24]  S. Engen,et al.  Population dynamical consequences of climate change for a small temperate songbird. , 2000, Science.

[25]  H. Weimerskirch,et al.  LONG‐TERM CONTRASTED RESPONSES TO CLIMATE OF TWO ANTARCTIC SEABIRD SPECIES , 2005 .

[26]  Takashi Saitoh,et al.  Constraints to projecting the effects of climate change on mammals , 2006 .

[27]  C. Gilbert,et al.  Foraging movements of emperor penguins at Pointe Géologie, Antarctica , 2007, Polar Biology.

[28]  S. Amstrup,et al.  Polar bears in the southern Beaufort Sea II: Demography and population growth in relation to sea ice conditions , 2007 .

[29]  V. Land,et al.  Management Plan for Antarctic Specially Protected Area No . 165 EDMONSON , 2011 .

[30]  P. Holgate,et al.  Matrix Population Models. , 1990 .

[31]  B. Kendall,et al.  Longevity can buffer plant and animal populations against changing climatic variability. , 2008, Ecology.

[32]  A. Lombarte,et al.  Daily ration of Antarctic silverfish ( Pleuragramma antarcticum Boulenger, 1902) in the Eastern Weddell Sea , 2004 .

[33]  H. L. Miller,et al.  Climate Change 2007: The Physical Science Basis , 2007 .

[34]  K. Arrigo,et al.  Decadal-scale changes in the climate and biota of the Pacific sector of the Southern Ocean, 1950s to the 1990s , 2005, Antarctic Science.

[35]  D. Etheridge,et al.  Recent southern Indian Ocean climate variability inferred from a Law Dome ice core: new insights for the interpretation of coastal Antarctic isotopic records , 2003 .

[36]  Y. Cherel.  Isotopic niches of emperor and Adélie penguins in Adélie Land, Antarctica , 2008 .

[37]  S. Solomon.  IPCC (2007): Climate Change The Physical Science Basis , 2007 .

[38]  Henri Weimerskirch,et al.  Emperor penguins and climate change , 2001, Nature.