Emperor penguins living in the Antarctic may be able to adapt to warming temperatures that are eroding their traditional breeding grounds, according to a study released this week.
Using satellite imagery and aerial surveys, researchers found four penguin colonies that had moved their breeding area to floating ice shelves from the normal sea ice that they usually rely upon.
Peter Fretwell of the British Antarctic Survey, the study's lead author, said in a statement that the iconic birds usually breed on the sea ice because it gives them clear access to waters where they can find food. Between 2008 and 2010, the sea ice was thick enough to sustain these colonies.
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But in 2011 and 2012, the sea ice didn't form until a month after the penguin breeding season began, so during those two years, the tuxedo-colored birds instead used the ice shelves between March or April and December.
It's thought that there are around 600,000 emperor penguins in the Antarctic, which has some of the world's coldest temperatures and highest winds.
"What's particularly surprising is that climbing up the sides of a floating ice shelf -- which at this site can be up to 30 meters [98 feet] high -- is a very difficult maneuver for emperor penguins. Whilst they are very agile swimmers, they have often been thought of as clumsy out of the water," Fretwell said.
He added in a telephone interview, "All the predictions and all the models suggest that sea ice will decrease rapidly in the next 20 to 50 years and we're going to lose a lot of emperor penguins because if the temperature increases, one of the first things to go is the sea ice." While models predict that Antarctic sea ice cover will decrease, it has actually slightly increased recently (ClimateWire, Oct. 1, 2013). However, any increase didn't seem to help the penguin colonies studied here.
Food problems may linger
Fretwell warned that using ice shelves is not a silver bullet for the penguins, who have been listed as "near threatened" on the International Union for Conservation of Nature Red List.
Ice shelves are farther away from their usual foraging grounds, and penguins are also more exposed to colder and windier weather on these flat and smooth shelves. It also may be difficult for the penguins to repeatedly climb up and down such a high ice shelf.
Fretwell said because of climate change, "We think emperor penguin numbers are going to decrease substantially ... and so this could be very beneficial in their fight against warmer temperatures."
Unfortunately, sea ice decline also could hurt the food sources of these penguins, which primarily munch on fish, squid and krill. Fretwell said there's a close link between the amount of sea ice and krill. These small crustaceans like to eat the algae that is under sea ice, so if the amount of sea ice declines, krill could also be hit, according to the Antarctic and Southern Ocean Coalition.
"These new findings are an important step forward in helping us understand what the future may hold for these animals, however, we cannot assume that this behavior is widespread in other penguin populations," Barbara Wienecke of the Australian Antarctic Division said in a statement. The division also participated in the research, along with the Scripps Institution of Oceanography at the University of California, San Diego.
"The ability of these four colonies to relocate to a different environment -- from sea ice to ice shelf -- in order to cope with local circumstances, was totally unexpected. We have yet to discover whether or not other species may also be adapting to changing environmental conditions."
Reprinted from Climatewire, with permission from Environment & Energy Publishing, LLC. www.eenews.net, 202-628-6500
