The Christmas Bird Count (CBC) provides the best population trend data for the American Tree Sparrow, since the survey almost covers the species' wintering range entirely. CBC results suggest that there has been a large decrease in the continental population relative to 1970. Though CBC results combine data from Canada and Alaska, the bulk of the American Tree Sparrow population breeds in Canada, thus the trend likely represents the Canadian population. The species breeds too far north to be well covered by the Breeding Bird Survey. The American Tree Sparrow is is below the lowest acceptable level relative to its national population goal (see Canada graph below).
Additional information on: Christmas Bird Count (CBC)
