Picky Eaters May Go Hungry in Antarctica with Climate Change

It looks as if picky eaters may be going hungry if climate change continues. Scientists have found two species responding very differently to a changing world, and their main difference happens to lie in what they eat.

In this case, the two species are the Chinstrap penguins and the Gentoo penguins. Chinstrap penguins are recognizable by the black stripe under their chins, while Gentoo penguins are recognizable by their bright orange beaks. While Chinstrap penguins are declining, though, Gentoo penguins are increasing at summer breeding colonies in the Antarctic Peninsula.

The Antarctic Peninsula has warmed dramatically over the past 50 years. In fact, the annual air temperature has increased by about 5 degree Fahrenheit, which makes the area the fastest warming region in the Southern Hemisphere.

Krill, which is the main prey for Chinstrap penguins, relies on sea ice. Young krill in particular use sea ice for protection from predators, and they feed on algae that grow beneath the ice. As temperatures warm, though, there is less of this habitat for the krill.

"Our data shows Gentoo penguins have a more diverse and flexible diet than Chinstrap penguins, which forage farther offshore and preferentially feed on Antarctic krill during the breeding season," said Michael Polito, the lead author of the new paper, in a news release.

Over five years, the researchers examined the stomach contents of breeding adult penguins. This revealed what an individual penguin was feeding its chick that day. The researchers found that Chinstrap penguins fed on the declining krill, while Gentoo penguins fed on several different food sources. In addition, Gentoo penguins are more flexible in when and where they breed. In the end, it turned out that the Gentoo penguins adaptability may explain why they're doing better than Chinstrap penguins.

"These may be the reasons why Gentoo penguins in the Antarctic Peninsula are benefiting from changes in climate and their populations, but Chinstrap penguins are decreasing," said Polito.

The findings are published in the journal Marine Ecology Progress Series.