Posted by: Mark Andrew Conboy
This autumn birders all over southern Ontario have reported sightings of boreal chickadees (Poecile hudsonicus), anunusual species to see south of Algonquin Provincial Park. Boreal chickadees typically inhabit the true boreal forest but also occur in low densities in the transition zone where the northern boreal forest mingles with the southern Great Lakes forest. In some years irruptions of boreal chickadees occur, bringing many of these birds into parts of Ontario where they do no normally occur. This autumn boreal chickadees have been widely reported in southern Ontario including from Prince Edward County, the Toronto Islands, Hamilton, Presqu’ile Provincial Park, Missassauga and Ottawa (ONTBIRDS listserv archives). Not to be out done, QUBS has also had one boreal chickadee at the Point on October 15. The bird was originally found with a flock of black-capped chickadees (Poecile atricapillus) near the bird feeders at Ironwood Cottage. It was located two days later alone on Cow Island but has not been reported since. This is the first record of boreal chickadee for QUBS.
Irruptions of boreal birds southward during some autumns and winters seems to be closely related to the availability of food. Many species of finches, Bohemian waxwings (Bombycilla garrulus), red-breasted nuthatches (Sitta canadensis) and boreal chickadees all irrupt into southern Ontario occasionally in response to shortages in the respective seed and fruit crops each species consumes. Raptors, owls and northern shrikes (Lanius excubitor) may all irrupt when small mammal prey is scarce or hidden under deep snow.
There are six other boreal chickadee irruptions on record for the Kingston region, the largest of which was the autumn, winter and spring of 1972-73 when 233 birds were recorded. In that irruption boreal chickadees were recorded between October 15, 1972 and April 7, 1973 (Weir 2008).
Weir, R.D. 2008. Birds of the Kingston Region 2nd edition, Quarry Press, Kingston.
Posted by Mark Andrew Conboy