A warming climate has spelled bad news for the thick-billed murre, one of the most common seabirds in Canada's North, a researcher has found.

Tony Gaston, a research scientist with the Canadian Wildlife Service in Ottawa, said the loss of sea ice over the last 30 years on Coates Island and in the Hudson Strait is affecting the survival of some murre chicks.

While the ice has been breaking up three weeks earlier than usual, Gaston said, the murres have adjusted their nesting habits by only a week in advance. The bigger the gap between break-up and nesting, the skinnier chicks tend to be, he noted.

"There is a relationship between the weight of the chicks when they leave the colony and the likelihood that they're going to come back to the colony subsequently," he said.

"For instance, a chick that leaves the colony at around 160 grams — which will be right at the lower edge of the range — has only about a 10 or 20 per cent chance of being seen again at the colony as an adult."

Gaston, who has been studying the thick-billed murres for the past 30 years, has already noticed the birds' diet has changed: from Arctic cod, a fish associated with ice, to capelin, which is normally found farther south.

In fact, capelin now make up 90 per cent of their diet, he said.

Gaston's team will expand its seabird research this year to include colonies in Lancaster Sound and Barrow Strait, and will look at the stomach contents of adult birds to see just how species in the ocean are changing because of warming temperatures and less sea ice.