New paper!


Melting Sea Ice Threatens Emperor Penguins

Published in the June 20th edition of the journal Global Change Biology

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The emperor penguin depends on sea ice, which is projected to shrink because of climate change. We measure how changes in sea ice affect emperor penguins and predict what may happen to them in the future, by estimating survival and breeding as functions of ice and linking the results to global climate models.

Wide range of possibilities

Different IPCC climate models which outputs agree well with past observations

Random variations du to natural climate variability

Effect of sea ice on breeding success and adult survival

Variations du to sampling effects and statistical analysis

Probability of “endangerment” by 2100

(population decline by 90% or more, i.e. less than 300 breeding pairs) is 42%

In November 2011, the Center of Biological Diversity filed a petition to protect the emperor penguin under the Endangered Species Act.

Optimal conditions for population growth occur at intermediate levels of sea ice. If sea ice changes as predicted by the climate models, the emperor penguin population in Terre Adélie will decline dramatically by 2100. Uncertainties in the population and climate models do not change these conclusions.

Optimal conditions for population growth occur at intermediate levels of sea ice. Neither the complete absence of sea ice, nor heavy and persistent sea ice, would provide satisfactory conditions for the emperor penguin.

“The ice-dependent emperor penguin is an Antarctic icon that has come to symbolize the threat of a warming world.”  Wormworth & Sekercioglu, 2011.

At nearly four feet tall, the Emperor penguin is Antarctica’s largest sea bird. Unlike other sea birds, Emperor penguins breed and raise their young almost exclusively on sea ice. If global temperatures continue to rise, sea ice will shrink and the Emperor penguins in Terre Adélie in East Antarctica may eventually disappear.

They can be observed walking in groups to the nearest open water areas where they feed. Disappearing sea ice may also affect the penguins’ food source. The birds feed primarily on fish, squid, and krill, a shrimp like animal, which in turn feeds on zooplankton and phytoplankton, tiny organisms that grow on the underside of the ice.

A group of Emperor penguin adults make their way across sea ice in Terre Adélie in East Antarctica. In December, the adults return to the colony to provide food for the chicks.

WHOI biologist Stephanie Jenouvrier readies an Emperor penguin chick (about five months old) for tagging during fieldwork in December 2011 in Terre Adélie. The research team (Centre d’Etudes Biologiques de Chizé et Institut Pluridisciplinaire Hubert Curien)   utilized Passive Inductive Transponder (PIT) Tag technology.

PIT technology  helps identify the birds and track demographic data, such as whether they return to the colony to breed and raise chicks.