No, we're not having an eruption! We're having an irruption, a now-and-then event that bird lovers always greet with delight. An irruption year means that feeders all over Vermont are now hosting birds that aren't our regular winter visitors, birds with flashes of brilliant gold, raspberry, even cherry pink!
Irruptions, also called “super flights”, are irregular large-scale migrations of birds to areas south of their normal wintering grounds, migrations that are usually prompted by food shortages.
Each fall, a Canadian ornithologist named Ron Pittaway monitors the abundance of spruce cones, birch seeds, mountain ash berries, and other native foods that boreal (northern) birds rely on for winter survival. He then puts out a forecast letting those of us to the south know what avian visitors might be showing up at our feeders. This year, seed crops are poor in much of eastern Canada, so Ron predicts that New Englanders will be seeing northern species we haven’t seen in several years.
The first of the irruptive species to show up at Chittenden County feeders were Pine Siskins. Siskins resemble goldfinches but are even smaller.
Pine Siskins are active little birds with sharp bills, lots of brown coloring, and lemon yellow edges on wings and tails. They are almost never seen alone!
Siskins descend on feeders en masse, making constant wheezy “zeeeeEEEET” noises.
Another tiny twittering species is just beginning to show up in Vermont.
Common Redpolls are named for the little red cap sported by both sexes. Ron Pittaway’s forecast says that we’re likely to see these birds first in weedy fields and then having “feeding frenzies” wherever they can find nyger or thistle seed.
Sometimes a flock of Common Redpolls might include a paler bird, a bird that looks like it's been touched by hoar frost. Hoary Redpolls are now considered a separate species, but ornithologists are debating whether they're actually just a variant or a "morph".
A larger and much flashier kind of northern visitor has also been showing up at many Vermont feeders.
Evening Grosbeaks have enormous bills designed for cracking hard seed casings to get at the nourishing food inside. The bills on these hefty birds makes them noticeable; the glorious colors cinch the identification.
Males are decked out in brilliant gold, black and white. Females are quieter but just as beautiful in their muted gray and yellow.
In the 1980s and ‘90s, Evening Grosbeaks used to descend on Vermont feeders in huge groups, voraciously eating pounds and pounds of black-oil sunflower seed. Their population was at an all-time high due to a spruce budworm infestation in their Canadian breeding grounds. (Grosbeaks love spruce budworms!) The beautiful birds are much less plentiful now, making them even more celebrated when they show up.