Climate change may force king penguins to swim too far for dinner

February 28, 2018, 11:21 a.m.
A massive group of king penguins on Salisbury Plain, South Georgia.
Photo: Liam Quinn/flickr

Roughly 70 percent of the world's king penguin population faces threats to its habitat by the end of the century, and the culprit will sound annoyingly familiar: climate change.

The challenge, according to a new model published in Nature Climate Change, is that penguins' favored foods — fish and squid — are moving further away from the islands where the penguins breed.

"Our work shows that almost 70 percent of king penguins — about 1.1 million breeding pairs — will have to relocate or disappear before the end of the century because of greenhouse gas emissions," Céline Le Bohec from the French National Centre for Scientific Research (CNRS) and the University of Strasbourg, told BBC News.

King penguins prefer to breed their young on sandy, ice-free sub-Antarctic islands, like South Georgia and the South Sandwich Islands (pictured), and swim hundreds of miles to reach the fish- and squid-filled Antarctic Polar Front (APF). The penguins get around 80 percent of their food from this band of water where deep cold water meets warm water.

The model predicts that the APF will drift further south, towards Antarctica, as the ocean warms, leaving the penguins with the choice of either swimming further and potentially starving their chicks or finding new islands for breeding.

By analyzing the birds' genetics, researchers have found that the birds have had similar crises in the past, particularly 20,000 years ago when sea ice was further north than it is now. So the birds may be able to bounce back by colonizing other islands, but this may not be the best solution for the penguins already using that island.

And will it happen soon enough?

"The problem is the pace of change. It is really very fast, and that will make it hard for the penguins to adapt," said Le Bohec.

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