Thursday, June 25, 2009

Cold Time for Birds

According to recent news reports, northern Canada is unusually cold this year.

According to Environment Canada, the spring of 2009 is record-late in the eastern Arctic with virtually 100 per cent snow cover from James Bay north as of June 11.

May temperatures in northern Manitoba were almost four degrees C below the long-term average of -0.7, and in early June, temperatures averaged three degrees below normal.

National Oceanic and Atmospheric Administration images confirm snow and ice blanket all of northern Manitoba, part of northern Ontario and almost all of the eastern Arctic as of June 12. U.S. arieal flight surveys confirm the eastern Arctic has no sign of spring so far.

"I have lived in Churchill since the 1950s, and this the latest spring I have ever seen here," said local resident Pat Penwarden. "The spring of 1962 was almost this bad."
The persistent cold has placed this year's breeding season in doubt for many shorebirds and other species. Arctic breeders only have a short window of time in which to mate, incubate their eggs, and rear their chicks. The longer the cold persists, the less likely they are to complete the process successfully.
According to Cornell University researchers, currently at Churchill, shorebird nesting is already three-weeks late, and has yet to start.

The first Canada goose nests were initiated on June 7, more than one month later than normal, and probably not early enough to allow goslings to mature before the fall migration flight. Canada geese are the first birds to nest in northern Manitoba. Many northern birds require more than 100 days to nest, incubate young and rear offspring to a condition suitable for fall migration.

According to Robert Rockwell of The City University of New York, who studies geese in northern Manitoba, if the geese have not begun incubating clutches of eggs before June 11, there is almost no chance that their offspring will be strong enough to endure the long southbound fall flight.
As a result, we may start seeing some southbound migrants early this year in the lower 48. Many birds simply will not nest. In 2004, many birds started heading south in late June, well ahead of the normal schedule.

Under normal circumstances, a lost breeding season would not be a disaster. Evolution has equipped most species with the ability to survive a bad year here or there without significant risk of extinction. But these are not normal circumstances. First, as the linked article notes, this is the fifth delayed spring in the past thirteen years, which seems to be unusually high. Second, some of the species that breed around the Hudson Bay are already in trouble for unrelated reasons. I hope that this would not prove to be a tipping point of sorts for them.

See aerial views and video of the still-frozen north at the Boreal Songbird Blog.