The brightly-colored Canada Warbler is sometimes called the “necklaced warbler” because of the band of black streaks across its lemon-yellow breast. An estimated 64% of the population nests in Canada’s boreal region.
This species spends less time on its breeding grounds than most warblers, being one of the last to arrive and among the first to depart; its total time on the breeding grounds may be no more than two months.
Breeding Bird Survey data show a population decline of 3.2% per year throughout the Canada Warbler’s breeding range, with the greatest declines in the Northeast. Forest fragmentation, over-browsing of the understory by deer, acid rain, and the spread of the woolly adelgid (which kills fir and hemlock trees), have all reduced available habitat.
Another serious threat to Canada Warbler populations is the loss of habitat in the northern Andes, where a substantial portion of the population winters.