Is the Emperor Penguin Marching Into Oblivion?

With their stout frames and slightly swollen bellies, the emperor penguins of Antarctica look as sturdy as can be. But climate change threatens the survival of the iconic species, according to new research.

The first continent-wide study of the seabirds featured in the documentary March of the Penguins predicts that by 2100 melting sea ice will eliminate half the population in two-thirds of penguin colonies. Sea ice serves as the emperor penguins’ breeding ground and provides the habitat for the krill they eat.

“All the known colonies will be declining,” said Hal Caswell, a scientist emeritus at the Woods Hole Oceanographic Institution and a co-author of the study. Caswell and lead author Stephanie Jenouvrier, a Woods Hole scientist, published the results of their study this week in the journal Nature Climate Change.

Caswell said that at century’s end, the emperor penguin’s current estimated population of 240,000 breeding pairs will shrink by a median 19 percent. That’s enough of a drop to warrant putting the four-foot tall seabirds on the United States Endangered Species List, according to the researchers. Earlier this year, the U.S. Fish and Wildlife Service agreed to conduct a full scientific review to determine whether the species is eligible for listing.

The Woods Hole researchers reached their conclusions by combining penguin population data with the Intergovernmental Panel on Climate Change’s projections of sea ice melt through 2100.

“Together these allow us to project the changes in all 45 known emperor penguin colonies,” said Caswell. “The most severely impacted locations are those that are predicted to experience both large reductions and high variability in sea ice concentration.”

The first known colony of emperor penguins disappeared in 2009 on Dion Island, part of a group of islands located off the west coast of Antarctica. The population of the colony featured in March of the Penguins at Terre Adélie has been reduced to half its original size.

Because climate effects are complex by nature, the research team included population modelers, penguin biologists, and climate scientists.

What should policymakers, land managers, scientists, and the international community be doing in response to the researcher’s dire penguin predictions?

Caswell believes the answer is simple and urgent. “This is another example that documents the effects of climate change on populations,” he said. “Actions to limit greenhouse gas emissions are critical.”