Monday, January 26, 2015

Jeremy Plester - Weatherwatch: The adaptable little auk

Sometimes the scale of climate change is so awesome that it seems incomprehensible. But the story of one small bird in the Arctic shows how temperatures are soaring, and also how it is adapting to an ecological disaster.
The little auk is a black-and-white bird sometimes called “the penguin of the north”, which dives in the frigid waters of the Arctic and swims underwater with small wings, feeding on minuscule animals known as copepods that gather around the sea ice.
Adult little auks, in summer plumage.
According to the Journal of Global Change Biology, since 2005 summer sea ice in the birds’ habitat on the Russian Arctic coast has virtually disappeared and the numbers of copepods has plummeted.
That should be bad news for the auks, but a recent study revealed that the birds have made a surprising switch – they now tend to feed on copepods that are stunned by cold, fresh water streaming down from melting glaciers on land.
The birds have managed to adapt but there is less food to go around and, as their feeding habits have changed, the body mass of the adults has dropped an average of four per cent since the early 1990s, a sign of something going wrong.
The little auk is especially vulnerable to climate change and is seen as a bellwether of the state of the polar north. The Arctic is warming twice as fast as the rest of the world; in this rapidly changing environment it is thought that some Arctic species may go extinct.