Saturday, September 20, 2008

Winter Finch Forecast, 2008-2009

Ron Pittaway has published his annual winter finch forecast, for "winter finches" and other irruptive species. The forecast gives an idea of what birders can expect to encounter, mainly in Ontario but also further south. Here are some highlights:

Purple Finch: This finch stays in the north only when most tree species have heavy seed crops. This fall most Purple Finches will migrate south out of the province because overall tree seed crops are too low. A very few may winter in southern Ontario.

Red Crossbill: This crossbill comprises nine ecotypes in North America; each has cone(s) preferences related to bill size and shape. The Types are difficult to identify in the field. Types 2 and 3 and probably 4 occur in Ontario. The white pine Type 2 is apparently the most frequently encountered Red Crossbill in the province (Simard 2007 in Atlas of Breeding Birds of Ontario). Since white pine has abundant crops in most areas, expect Type 2s to be widespread in small numbers. Hemlock Type 3 (subspecies sitkensis of AOU Check-list 1957) prefers the small cones of hemlock and white spruce when bumper in Ontario. Type 3s should be absent from the province this winter because the hemlock crop is poor and the white spruce crop is average. Other Types are possible this winter given the bumper white pine cone crop and good crop on red pine. The Red Crossbill complex very much needs further study.

White-winged Crossbill: This crossbill wandered widely this past summer searching for extensive spruce cone crops. Reports came from Alaska, Yukon, Hudson Bay Lowlands, Ontario, Quebec and many northern states such as Michigan and New York. Most kept moving but some stopped and their singing suggested nesting but spruce cone crops are generally not large enough in most areas to support major nestings. The White-winged Crossbill specializes on the small soft cones of black and white spruces and hemlock when bumper in Ontario. This winter they should be widespread in small numbers in traditional areas such as Algonquin Park. However, spruce cone crops are generally low in most of Canada and as seed supplies are exhausted this fall and winter so a moderate southward irruption is probable, perhaps extending south into the central United States. Watch for them on ornamental spruces and European larch.

Pine Siskin: A conifer seed specialist in winter, most siskins should leave the province this fall because the spruce cone crop is poor in the boreal forest. It is uncertain whether the huge white pine seed crop will keep some siskins in central and northern Ontario this winter.

Boreal Owl: Small mammal populations have crashed across northern and central Ontario. In Quebec, Pascal Cote of Observatoire d'oiseaux de Tadoussac expects a flight of Boreal Owls this fall and winter following their 4 year cycle linked to red-backed voles. Southern Ontario may get Boreal Owls and other northern forest owls this winter.
There is lots more at the link.