One way to identify a common redpoll is to spot that namesake red patch on the crown of the head; both males and females have a crimson poll. Can’t see it? Look for a black patch under the bird’s chin. Unfortunately, this ID trick won’t help you tell a common redpoll from the nearly-identical hoary redpoll—even experts have a hard time differentiating between the two. That said, in case you’re especially eagle-eyed: hoaries are usually slightly paler, with a somewhat smaller beak.
Redpolls are one of the most northern-breeding finches in North America. As such, cottagers are more likely to see them during the cold season, when they move from their summer ranges in the farthest tips of Nunavut, the Yukon, and the Northwest territories, to the relatively warmer parts of Canada, and sometimes even into the central U.S.
These plump, small-beaked songbirds travel and forage in buzzy, energetic flocks. They’re “gleaning” birds, and will hang upside down from the end of a branch to get at the undersides of leaves, where they’ll find tasty insects and spiders in milder temperatures. (Other species—ones with larger mouths, such as swallows—are aerial foragers. They snatch flying bugs mid-air.)
To survive severe winter weather, redpolls eat 40 per cent of their body weight in seeds every day, usually birch and alder. (Attention, bird lovers: these finches are fond of scoring thistle, plus nyjer and sunflower seeds, at feeders.) Common redpolls have a special throat sac, called a diverticula, where they store gathered seeds in winter. They can forage in open, unprotected areas, then move to a more sheltered spot, to eat in peace. Regurgitated seeds, mmmm.