American Birding Podcast



Happening NOW: Irruption of Winter Finches Underway

In July, a small, charismatic passerine began arriving at feeders and migrant traps in the mid-Atlantic and southeast—well outside its breeding range. Birding listervs, text groups, eBird rarity alerts, and the like lit up with the news: Red-breasted Nuthatches were on the move. Though it was still mid-summer at the time, this clued birders for what the fall might bring—winter finches.

As a group of birds, winter finches have an ability to define a season in a way few other birds do. When thinking back on seasons past, I often find myself using the movements of finches and similar irruptive migrants as bookmarks—while I might not remember how warm or cool a winter was, I can usually remember how many Pine Siskins or Common Redpolls I saw and use that to ground my other recollections. What makes them so memorable, in my opinion, is how unpredictable they seem. Of course, I say “seem” because if you know what to pay attention to, the movements of these birds may be quite possible to foresee. Most of these irruptions are fueled by lack of food. When a typically prolific and reliable berry or cone crop fails, birds are forced to wander farther to look for substitute food sources. These failures are influenced by many factors, but are also somewhat cyclical, meaning that birders can predict—with varying degrees of accuracy—which winter irruptives may move and how far they may travel.

In my part of the world, the last significant finch movement was the fall of my freshman year of college—Red-breasted Nuthatches arrived early, as they did this year, followed by Purple Finches in late September, and a few Pine Siskins shortly thereafter. Remembering this, when the nuthatches began showing up, I started looking ahead for the arrival of these and other species. Soon enough, the Purple Finches and Pine Siskins arrived—the former in numbers rarely seen before. However, none of these was the species I was hoping for the most—the spectacular Evening Grosbeak.

The Evening Grosbeak is an enigmatic species. It is large, bright, and distinctive, rendering it recognizable to even casual feeder-watchers, and was formerly considered a common and widespread winter backyard bird across much of the ABA Area. What followed was a marked decline in abundance and contraction in range. By the time I was birding seriously, it was a relative rarity in the mid-Atlantic and its appearance was limited to major irruption years. For more about that, readers can refer to this post from the last large-scale irruption, in 2012Since that season, there have been no large and widespread movements of that species. Until this year.

Over the past month or so, Evening Grosbeaks began to move beyond the limits of their normal winter ranges. Many years, Eastern birders consider themselves lucky if Evening Grosbeaks are seen outside of upstate New York and New England and birders in the Midwest may miss the species entirely, even in decent years. So far this year, eBird data are showing a different story. Since October, birds have made it as far south as Northampton County, Virginia, in the east and Ohio, Indiana, Wisconsin, and Michigan have all racked up multiple reports.

During what may become an unprecedented irruption of Evening Grosbeaks in recent memory, birders also have a unique opportunity to contribute to our knowledge of this species. Many birders don’t realize that, just like the Red Crossbill, there are actually several populations of Evening Grosbeaks composed of different “types”, mostly identified by variations in the birds’ vocalizations. Our understanding of these types is fuzzy, perhaps even more so than our understanding of Red Crossbill types. Take a look at this previous post for a neat summary of that situation. As a result, sharing your sightings of Evening Grosbeaks, and especially any recordings you might make, would be an incredible opportunity to increase our knowledge of this species.

I would also be remiss not to note that this is exactly the kind of bird status and distribution event that we at North American Birds love to dig into. This topic could fill many additional pages and include many species beyond the ones I’ve mentioned here. Common and Hoary Redpolls and Bohemian Waxwings may also be poised for irruptions and there is some evidence that White-winged Crossbills may undertake some limited movements. Hopefully those pages will be in future issues of NAB and will include a broader analysis of both what happened and why. But until then, get outside and enjoy this wonderful opportunity. Fill your feeders, charge your camera battery, fire up your favorite sound recording app, and find some Evening Grosbeaks. And then put all of the information on eBird! Seriously, this is a time to contribute some valuable knowledge while enjoying one of the most impressive winter finches in the ABA area.