Siskins making significant appearance in N.C. for first time since 2008-09 winter

Purple finches and red-breasted nuthatches also show irruptive behavior, apparently affected by the same shortage of winter foods, and all three species occur during the same winters. The finches occur in numbers rivaling siskins, but the nuthatches are usually seen just one at a time instead of in flocks.

The breeding range of pine siskins spans from coniferous forests in coastal Alaska all the way to Newfoundland. In those winters when food resources are diminished, one might expect irruptive flocks of siskins to simply go southward, following the shortest route to plentitude, and many do just that. But the U.S. Bird Banding Laboratory found that some siskins take a quite different route. The laboratory amassed data for siskins that were banded in the United States and Canada between September 2008 and July 2010. Though only 46 birds were recovered of the 31,004 banded, they revealed some surprises. Although several birds migrated as expected: south in winter and north in spring; a few flew much longer distances: to the east in winter, returning to the west in spring.

One of these birds flew from central Pennsylvania to western Washington State, while another flew from central New York State to Vancouver Island, British Columbia, about 2250 miles and 2500 miles respectively, and that’s assuming they flew in a straight line.

As I was concluding my Stone Mountain hike, a dozen siskins returned to the Hutchinson Homestead, dropping into a patch of weeds in the meadow. Dandelion stems bobbed up and down with the half-ounce weight of each bird as they plucked seeds from the puffballs. For each seed consumed, several more were set adrift on the breeze, floating way like diminutive parachutes.