Warming Arctic disrupts birds' breeding
Tuesday, April 27 2010 @ 03:09 PM EDT
Contributed by: jkr
Some species arriving from south a month ahead of schedule
By Jane George, Nunatsiaq News
As Arctic temperatures warm and weather becomes less predictable, migratory birds may face new challenges and some nasty surprises when they return North, researchers with the Canadian Wildlife Service say.
Birds sometimes arrive at their northern breeding grounds earlier than they used to, driven by warm weather in the South, only to find no food there when they arrive.
And, once they are in the Arctic, increasingly unpredictable weather can cause them additional misery.
Due to higher than average temperatures in many parts of Nunavut this past winter, birds are already flocking back to the High Arctic.
In Cambridge Bay, Nunavut, where Environment Canada says temperatures were five to six degrees above normal this past winter, and warm again into March and April, snow buntings have returned -- a full month earlier than usual.
This means Canada geese, snow geese and other migratory birds aren't far behind, hunters say.
But when the birds finally arrive at their destination, their breeding cycle could be turned upside down.
That's because the breeding schedules of these birds may be out of whack with nature and as a result they may lack food for their young.
The birds' arrival may not follow the same pace of change as the environment, producing what wildlife biologists called a "mismatch"-- where wildlife habits change, but the environment lags behind.
For instance, researchers with Laval University have found that high spring and summer temperatures led to fewer young surviving among snow geese on Bylot Island. And when warmer weather combined with increased numbers of mosquitoes, they contributed to higher numbers of deaths in some seabird colonies, say biologists with the Canadian Wildlife Service.
Since the 1970s, CWS biologists have seen severe weather produce many lethal situations for seabirds.