Sunday, September 20, 2009

Winter Finch Forecast for 2009-2010

Ron Pittaway has released via email his annual forecast for irruptions of winter finches and other boreal species. (An irruption is a mass movement of birds in response to food shortages or other temporary conditions. Read more about irruptive birds at Seabrooke's blog.) The upshot is that he expects very few finches (or other birds) to come south this year. Instead, many finches will either stay north or head west. The reason is that key food crops (the seeds of spruces, birches, mountain-ashes, and other trees) are excellent this year across Canada.

There are a few possible highlights, though. Note that the forecasts are written from the perspective of someone living in Ontario.
Purple Finch: Most Purple Finches should migrate south out of the province this fall because many seed crops are poor in the north. This finch has declined significantly in recent decades.

Common and Hoary Redpolls: Redpolls are a birch seed specialist in winter. Since the birch crop is poor in northeastern Ontario and Quebec, a few Common Redpolls should move south into southern Ontario and farther east and south. However, most redpolls may be drawn to good birch crops in northwestern Ontario and westward in the boreal forest into Saskatchewan.

Northern Goshawk: A good flight is very possible this fall or next. Goshawks in the boreal forest in winter prey on hares, grouse and red squirrels. Snowshoe Hares have been abundant in parts of northern Ontario the past few years and they should crash soon. Also, Ruffed Grouse likely had a poor breeding season due to a cool, wet spring and summer, which lowered chick survival.

You can find Pittaway's full forecast at the Ontario Field Ornithologists website.

Highlights from past forecasts are available on this blog: 2008-09, 2007-08, 2006-07, 2005-06