From the time we are children, we know that birds fly south for the winter. Think of hummingbirds that disappear before the first frost, skeins of honking geese cutting through the crisp autumn air, or warblers and tanagers abandoning northern forests and beating it for food-rich Central American jungles.
But there’s a group of tough, renegade birds that don’t play by the rules. They fly where and when they want, regardless of season or weather. Some years we see them, some years we don’t. Who are these feathered rogues? They are the winter finches.
The winter finches are a loose collective of northerly nesting songbird species, most of which are indeed finches related to the House Finches and goldfinches that clean out your bird feeders. They include the crossbills, the redpolls, Pine Siskins, Evening and Pine Grosbeaks, and Bohemian Waxwings, which are not really finches. These birds breed in the vast, cool boreal forests that cover much of the northern latitudes of the planet. What the different species have in common is a dependence on the cones, seeds, and fruits of various boreal trees for food. When crops of these trees they fail, the birds pick up and move. This strategy of completely leaving their breeding range and invading new areas at unpredictable intervals is known as “irruption," with an “i," and is distinct from migration in the traditional sense.
It’s hard to know when and where they will turn up, but a Canadian birder named Ron Pittaway has taken on the task of trying to forecast the winter finch flight each year. He checks his network of biologists and birders throughout the boreal forests of Canada to assess seed crops of spruces, birches, and mountain ash, and to get word of any early season movements of indicator species like Red-breasted Nuthatches and crossbills. He puts all of this information together in his annual “Winter Finch Forecast," which birders devour when it comes out each fall.
One winter finch you might catch at your feeders in a good flight year is the Common Redpoll. They are closely related to goldfinches, and as such are fond of niger seed. Same goes for another feeder patron, the Pine Siskin. Both redpolls and siskins are streaky little brown jobs at first glance, but they do sport some color if you look closely. Redpolls have a spot of red on the front of the head, and siskins show flashes of yellow in the wings and tail. If you happen to look out your kitchen window and see some winter finches, and even if you don’t, hopefully you are reporting your feeder birds to Cornell’s Project Feederwatch or to eBird, or better yet, both!
We’ve had just a hint of winter finches here on the Cape and Islands so far this fall, with a couple of scattered sightings of Evening Grosbeaks and even Pine Grosbeaks, which are by far the rarest of the lot. Red Crossbills have been seen a couple of times as well. The two crossbill species - Red and White-winged - are my personal favorites among the finches. They have these really fun crossed-tip bills that are designed for efficiently extracting seeds from cones. With their unpredictable movements, willingness to nest in the middle of winter when food is abundant, and complicated subspecies structure, these guys are cool enough to get their own week on the Bird Report, so stay tuned for that.
The other day I was excited to stumble across a sizeable flock of Red Crossbills in Orleans. Because it was a warm day, I had my windows open and heard their chattering as I drove by. For me, driving is just birding, only faster. So does this mean more crossbills are on the way? Let’s hope so, but we won’t know if you don’t get out there and look!