Sunday, January 20, 2013

Redpolls and their Allies

Common Redpolls don’t show up every winter, but in the years when they do come, they can come in big numbers - frequently in flocks of over 100. The Common Redpoll is a small finch, and is about the same size as our American Goldfinch. In fact, they produce some similar call notes and display some similar behavior as that familiar species.
Only the adult male Redpoll has a rosy chest
When they first arrive in this area, I don't usually find them at bird feeders right away. Instead, I find them in the birch trees. The seeds of the Birch are a staple food of the Redpolls, and these birds seek them out throughout their expansive range. For a few weeks in early winter, whenever I would find birch catkins scattered beneath a tree, it was a safe bet that a flock of Redpolls had been actively foraging.
Redpolls of both sexes have the distinctive  red cap and the small black chin patch
Redpolls are able to store seeds in a throat pouch. This is a useful adaptation for a species that sometimes must travel long distances between food sources. When they do find bird feeders, their seed of preference is usually thistle or nyjer seed, but they also readily feed on sunflower seeds. For us, it’s most often in the second half of the winter that the Redpolls begin coalescing around the bird feeders. When they do, they can become very reliable patrons – visiting daily and necessitating frequent refilling of the feeders. 
A newly arrived flock of Common Redpolls feeds on  the seeds of a Gray Birch
Redpolls often allow a close approach and so it is easy to get a really good look at them even without binoculars. This is true of a number of bird species from the far north, including some of the owls, ptarmigan and some of the other finches. It’s thought that these species’ general lack of experience with humans is responsible for their boldness.
The Common Redpoll is a bird of the Arctic. There they spend the summer breeding season on the tundra and into the boreal forest. They typically build their well-insulated nests in shrubs or low conifers. They will only come south of the Canadian border when their natural food supplies are lacking. This is when they are forced to push into or “irrupt” into other regions.
The adult male Hoary Redpoll shows a considerable amount of white plumage
The Hoary Redpoll 's back has a frosty appearance 
In years when the influx of Common Redpolls is especially large, we sometimes get another species of Redpoll mixed in among the crowd. The Hoary Redpoll looks like a whiter version of the Common Redpoll. They have noticeable less streaking on their flanks and none under their tails. They also have stouter bills, which tends to be much easier to discern when the Hoary is seen perched right next to a Common Redpoll, and it’s possible to make a direct comparison.
The Pine Siskin appears heavily streaked, and has a longer bill that other small finches

Note the yellow tail feathers on this siskin
The Pine Siskin is another heavily streaked small finch whose visits from are unpredictable. Individual siskins show varying amounts of yellow on their wings and tail. The species also has a much longer bill than either the Goldfinch or the Redpoll, and that feature can help you pick them out in a mixed flock of winter finches. Unlike the Redpolls, the breeding range for the siskin extends well into the US, particularly in higher elevations where there is boreal forest. Also, unlike the Redpolls, we've had siskins visit our feeders in all seasons of the year, though rarely in successive years.
A group of Evening Grosbeaks (and one House Sparrow) perch in one of the nature preserve's sumac trees 
Other winter finches came through the region this winter, but few stayed long. Throughout our Central New York State region, the amount of food in the wild is low this year, and for the most part, the larger finches like Evening Grosbeak, Pine Grosbeak and the 2 species of crossbill have been forced to try their luck  in other regions.
A male Pine Grosbeak feeds heartily on Crab Apples

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