The common redpoll is irrupting again. This is because it's partial to seeds - especially from coniferous trees. It feeds on the seeds of evergreen trees from the very northern part of the United States and the southern provinces of Canada, but not into the tundra. If those areas are short on cones, then the birds move south to where there is more food. However, usually not below the 40th parallel.
What causes the food shortage? When there is a good crop of seeds, more birds take advantage of it. That may be followed by a year of crop failure. That's a simplified explanation of the phenomenon in a nutshell. No, I should say seed shell.
The redpoll is in the same family as the hoary redpoll, house finch and purple finch. They all range from 5--inches long at their smallest. It's about the same size as the American goldfinch and pine siskin.You can't use size as a definitive way to tell the redpolls and finches apart. The common redpoll has a brown back with a red topknot. It has just a smidgeon of black on the throat - not the black down the breast like the house sparrow. The male has a pink breast.
When the cold air descends on us, the common redpolls might come to escape the colder temperatures in Canada.
Look for it mostly in birch trees. It thinks that its seeds are the best. However, one might see it in weeds, brush and open areas also. In the tundra, it likes the scrub, which is a good source of seeds. Forbs and grass are also consumed. Insects are consumed if they are available in large numbers.
Do you wonder how it survives the subarctic winters? Like gallinaceous birds - domestic fowl, pheasants, grouse and partridges - it has a pocket with two sections about halfway down the neck. That's called an "esophageal diverticulum." Seeds are stored there in the evening, especially in bad weather. That helps it survive the cold temperatures. The sheltered bird can feed at night without having to go out into the ugly winter weather. It could be similar to humans raiding the refrigerator in the middle of the night.
Another method to survive the cold is to find the shelter of a coniferous (evergreen) forest, fluff up its feathers and remain extremely still. I read that redpolls can survive the cold better than any other songbird.
Studies have shown that a flock will have a strict social hierarchy. The male dominates the female during the nonbreeding season. That relationship changes. The female becomes dominant during the entire breeding season. The male feeds the female during incubation.
Let's discuss the family life of the redpoll. When the male is courting the female, she hunkers down, droops her wings and twitters. Gallantly, he stands tall and bows to her.
The nest is constructed of twigs with a lining of finer twigs, rootlets, grass, lichen and moss. Ptarmigan feathers, plant down, and fur make it really soft for the young and mama.
Redpolls aren't particularly territorial. Sometimes, they nest quite close together. Nor do they return to the same breeding or wintering area. Now, that's free as a bird.
Singing mostly happens when the winter flocks break up. By the way, those flocks are usually composed of less than 100 birds.
What are other irruptive birds? Bohemian and cedar waxwings, pine and evening grosbeaks, black-capped and boreal chickadees, red-breasted nuthatches, pine siskins, common and hoary redpolls, purple finches, Clark's nutcrackers, and red and white-winged crossbills. I disagree with this list provided by one of my sources. Black-capped chickadees and purple finches live on my property all year long.
Flocks of redpolls won't easily be scared of humans. You might be able to get very close to them. That's good news for you photographers. You just have to be careful when they are feeding on the road. They get right out on the pavement.
David Thoreau wrote of the redpolls. "What a rich contrast! Tropical colors, crimson breasts, on cold white snow! Such etherealness, such delicacy in their forms, such ripeness in their colors, in this stern and barren season!" Isn't that eloquent? Keep on the lookout.