Global warming may rob emperor penguins of their resting place

Researchers tracking the behaviour of emperor penguins have found fresh reason to be worried about global warming — emperor penguins use sea ice to rest as they forage.

Research by Shinichi Watanabe of Fukuyama University, Japan and colleagues, described the foraging behaviour of the emperor penguins, and tracked the birds during the chick-rearing season.

Unlike other species like Adelie penguins, emperor penguins spent much more time diving for food, and only used about 30% of their time at sea to take short breaks to rest on sea ice, the journal Public Library of Science ONE reports. The birds did not travel for long distances on the ice, or use it for other activities.

Further, the study suggests that these short rest periods on ice help the penguins avoid predators such as leopard seal, according to a Fukuyama statement.

Though sea ice conditions are known to affect penguin populations, the relationship between ice levels and penguins' foraging has been unclear because of the difficulties of tracking the birds at sea.