Some emperor penguins seem to be responding to a warmer Antarctic by moving onto ice shelves to raise their young.
The large birds, which can weigh as much as 45 kilos, usually breed on floating sea ice, which gives them easy access to water where they hunt for food.
Multi-year satellite observations of one particular colony revealed that the sea ice was dense enough during the winters of 2008 through 2010 for the colony to thrive. But the following year, and again in 2012, the ice did not form until after the breeding season began.
A team of Antarctic scientists reports in the journal PLOS One
that the birds climbed onto a floating ice shelf instead to lay and hatch their eggs.
Lead author Peter Fretwell, with the British Antarctic Survey, explains that it is very difficult for penguins to maneuver up the cliff of an ice shelf, which can be anywhere from 30 meters to 60 meters high. They are agile swimmers, but not very efficient climbers.
The discovery of this unexpected behavior suggests that emperor penguins may be able to adapt to the changing climate, but the scientists observing them stress that it is still unknown whether other colonies, or other species, also may be able to adapt.