Most migrant Short-billed Dowitchers seen in southern Ontario are the
interior or central subspecies hendersoni. Hendersoni breeds mainly
from Manitoba westward across the northern Prairie Provinces. Griseus
breeds primarily in Quebec. Ontario is between Quebec and Manitoba.
Short-billed Dowitchers breeding in northern Ontario include both
subspecies and intergrades. Even some Short-billed Dowitchers
breeding at Churchill, Manitoba in the geographical range of
hendersoni show strong tendencies of intergradation towards griseus.
Migrants seen in southern Ontario reflect the variation seen northern
Ontario and at Churchill. See photos of some of the variation in
northbound hendersoni from Point Pelee, Ontario in May 2007.
http://www.jeaniron.ca/Shorebirds/2007/sbdowitchers.htm
Get ready because the first southbound adult female Short-billed
Dowitchers will be back in less than a month.
Jean Iron & Ron Pittaway
Toronto ON