Changing Winter Distribution and Abundance of the Blue Jay, 1962-1971

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Abstract
Audubon Society Christmas count data indicate that between 1962-1971 the North American blue jay population (Cyanocitta cristata) increased about 30%, and that migration of this species declined. The most likely cause was the increase in winter feeding by man. Results of this study suggest that winter food supplies and over-winter survival are (or, at least, were) limiting to northern blue jay populations.