. The Canadian field-naturalist. [977 MiDDLETON: American Goldfinch Overwintering in Ontario 169 TEMPERATURE 50 55 60 eA 70 r 75. 12 Or 100- 45 50 55 60 65 ANNUAL SNOWFALL Figure 4. Temperature and snowfall trends for southern Canada. 1940-1970, as based on records of Environment Canada (Thomas 1975). (Temperature data from airports at Kapuskasing, London, and Ottawa. Snowfall data from airports at Toronto. Ottawa. Montreal, and Quebec City.) Over the 4-year period for which data were obtained (1969-1973), wholesale sales (records of three companies) of seed for feeding wild birds rose by 50%
. The Canadian field-naturalist. [977 MiDDLETON: American Goldfinch Overwintering in Ontario 169 TEMPERATURE 50 55 60 eA 70 r 75. 12 Or 100- 45 50 55 60 65 ANNUAL SNOWFALL Figure 4. Temperature and snowfall trends for southern Canada. 1940-1970, as based on records of Environment Canada (Thomas 1975). (Temperature data from airports at Kapuskasing, London, and Ottawa. Snowfall data from airports at Toronto. Ottawa. Montreal, and Quebec City.) Over the 4-year period for which data were obtained (1969-1973), wholesale sales (records of three companies) of seed for feeding wild birds rose by 50% from 340 tons to 510 tons. Retail sales for the same period (records of five companies) showed an increase of 131% from 350 tons to 810 tons. Discussion Traditionally it has been accepted that gold- finches in Ontario and neighboring regions migrate south for the winter (Dawson 1903; Dionne 1906; Snyder 1951; Godfrey 1966; Tyler 1968). It is known that goldfinches do migrate (records of Bird-Banding Office, United States Fish and Wildlife Service; A. L. A. Middleton, unpublished), but there are records to suggest that some goldfinches have consistently attemp- ted to overwinter in southern Ontario and neigh- boring regions (Mcllwraith 1894; Dawson 1903; Barrows 1912; Snyder 1951; Forbush and May 1955). Attempts at overwintering may have been more common than reported as the goldfinch is inconspicuous during winter and often feeds with other species (Tyler 1968). Additionally, as the goldfinch feeds mainly on the seeds of the compositae (A. L. A. Middleton, unpublished) it is less dependent on the seeds of trees than other northern carduelines. As a result, its populations do not show the marked fluctua- tions during winter which make other species conspicuous by their presence or absence (Bock and Lepthien 1976b). Thus the presence of the goldfinch can be easily overlooked. The evidence shows, however, that during the last 60 years overwintering by goldfinches in Ontario has in
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