A study in Alaska documented that Common Redpolls could survive temperatures of -65°F.
Irruptive migrations of Common Redpolls and Purple Finches typically occur every two years or so.
Common Redpolls are small songbirds with small heads and small, pointed, seed-eating bills. The tail is short with a small notch at the tip.
They are brown and white birds with heavily streaked sides. Look for a small red forehead patch, black feathering around a yellow bill, and two white wingbars. Males have a pale red vest on the chest and upper flanks.
Redpolls travel in flocks of up to several hundred individuals. They move frenetically, foraging on seeds in weedy fields or small trees one minute and swirling away in a mass of chattering birds the next. Their buzzy zap and rising dreeee calls are distinctive.
A Common Redpoll banded in Michigan was subsequently recovered in eastern Siberia.
Common Redpolls will quickly gather numerous whole seeds and store them in an expandable section of their throat called the diverticulum. Once they have flown to the safety of dense cover they will regurgitate the whole seed, husk it and then re-swallow the nut meat. They will also fill the diverticulum with seed just before the onset of darkness in order to provide an extra source of energy to help them survive the night.
Look for Common Redpolls in areas ranging from willow flats to open conifer forest to open, weedy fields. They visit backyard bird feeders as well, especially during the winter.
Redpolls are described as irruptive migrants. Common Redpolls move south irregularly in winter following patterns in food supply. Along with Pine Siskins they are among the best known finches to do this. On a roughly 2-year cycle, redpolls come far south in winter and occasionally reach the central or southern United States. The movements generally correspond to the availability of seeds.
A study in Alaska documented that Common Redpolls could survive temperatures of -65°F.