This year is already turning out to be one of those years. Birders call it an irruption – different from an eruption, which happens to volcanoes – or an invasion, and it typically occurs with a group of a half dozen species of finch, though a few others are sometimes included in the mix.
It started in October when nearly every birdwatcher I know reported seeing large numbers of pine siskins at their feeders during the third week of the month. These small birds look somewhat like
|Pine siskin (Simon Pierre Barrett)|
streaky versions of our common American goldfinch, and we usually only see them during irruption years. They typically feed on spruce cones in the boreal forest of Canada, but apparently this hasn’t been a good year for spruce cones up there, and sunflower and thistle seeds appear to be a satisfactory substitute.
One morning last month I noticed one siskin scavenging the spilled seed beneath my feeder, and 20 minutes later there were nine. By the end of the day there were more than 50. I spent the next several days repeatedly counting and watching this mass of dainty birds far outnumbering my usual feathered visitors. And I couldn’t have been happier – though I immediately knew my bird feeding budget was going to skyrocket this winter.
Around the same time, a red-breasted nuthatch made its first appearance in my yard in several years. These little sprites are closely related to the white-breasted nuthatches that are common residents in Rhode Island, but with a pale rusty chest and belly and black-and-white stripes on the side of its face. Although they aren’t a finch and a few are seen in Rhode Island every year, they only appear widely across the region during irruption years.
A few other invading finches are staying home this winter. Common redpolls, which feed on the catkins of birch trees, apparently have enough to eat in Canada, so they aren’t expected in Rhode Island this year. The same is true of red crossbills, with their oddly crossed beaks, who feed on the cones of white pines. They occasionally invade the Ocean State, but not this year.
The most anticipated of this year’s invaders is the evening grosbeak. Dressed in gold and black and cream with an oversized seed-crunching beak, they look somewhat like a gigantic goldfinch. They used to be regular winter visitors 40 or 50 years ago, but not any longer. So birders are forced to wait for irruption years to get a look at them. And while there are usually enough pine siskins around during a big year for almost everyone to see one at their feeders, evening grosbeaks seldom turn up in huge numbers, so birders often have to scout out their neighbors’ feeders to find one.
I still haven’t come across an evening grosbeak yet this season, but I know they’re around. It’s one of the species that makes winter birding in Rhode Island exciting. For while most events in the natural world can be counted on to occur at the same time every year, the cycle of the irruption of winter finches into our area is difficult to predict. And I’m determined not to miss it.
This article first appeared in The Independent on Nov. 14, 2020.