Alaskan black guillemots fight ice retreat

A small colony of black guillemots living on a gravel spit off Point Barrow is providing a unique insight into the changing Arctic environment.

The Cooper Island birds feed their young on cod that hug the underside and edges of the polar pack ice.

But their access to this prey source is being limited by the big retreat in seasonal ice cover now under way.

How the guillemots respond will turn a lens on the wider changes taking place in Arctic ecosystems, biologists say.

"Things could go either way for these birds," explains George Divoky, who has studied the guillemots since 1975.

"It's just not known at this stage whether they will be able to cope with the big change by adapting to new food sources, or if they will have lower and lower breeding success until the colony eventually disappears," he told BBC News.

Dr Divoky was speaking here at the American Geophysical Union (AGU) Fall Meeting, the largest annual gathering of Earth scientists.

The bird biologist spends three months of the year on Cooper Island, which is about 40km east of the Alaskan town of Barrow.

Continued:  http://www.bbc.co.uk/nature/20498368