Cool fact: An irruptive species, Common Redpolls display irregular migratory movements by streaming south from Canada every few years during the winter months. These irruptions are thought to be tied to the availability (or lack thereof) of wild food on their normal winter range. Most notably, when birch catkins are low in abundance, tremendous numbers of Common Redpolls head south. Common Redpoll irruptions are global in naturethey have been recorded in Europe and Asia as well. During irruption years, Common Redpolls often frequent bird feeders. By mid-winter, they can be seen at in large flocks, which sometimes can reach thousands of individuals. Mid-March marks the start of the Common Redpoll's journey north.
Common Redpolls are approximately 5 to 5.5 inches (12 to 14 centimeters) in length. A small gray-brown finch with a deeply forked tail, Common Redpolls have highly variable plumage characteristics.
Description: A Common Redpoll is a streaky finch with pale feathered edges. The forehead and crown are red, whereas the lores and chin are black. The eye line is dark; the supercilium is pale. The cheeks are a darker gray than the rest of the head and nape. The median and greater coverts are solid gray with broad pale tips that create two wing bars. The flight and tail feathers are gray with buff-colored edges. The rump is pale and streaked with gray. The breast, flanks, and belly are whitish in color. The breast and flanks are streaked, but the amount of streaking varies. Males have a variable amount of rose wash across the upper breast that is not apparent in females. The yellow bill is sharply pointed, with a black tip and culmen.
Common Redpolls breed in the Holarctic region, which comprises the northern parts of the Old and New Worlds.
Four races of Common Redpoll exist:
Carduelis flammea flammea: This Holarctic race can be found in a broad band across the Arctic, with pockets to the south in Newfoundland and central Russia. This race of redpoll is most frequently found in North America during irruptions.
Carduelis flammea rostrata: This race, found in Greenland, is larger and browner than Carduelis flammea flammea.
Carduelis flammea cabaret: Found in Europe, this is the smallest race of Common Redpoll.
Carduelis flammea islandica: This race makes its home in Iceland.
It is difficult to identify specific races of the Common Redpoll because of the extreme variability in each bird's plumage. It is also difficult to identify the less-common Hoary Redpoll (Carduelis hornemanni). Care and careful observations are a necessity.