On a warm summer evening, sometime in mid-June, I found myself sitting on a dock in central Wisconsin, unwinding after a long day spent working on that state’s breeding bird atlas. Mid-sip on a Summer Shandy, that familiar sound met my ears: jip-jip-jip. Distant at first, they soon approached the lake, appeared as a duo overhead, and eventually departed south. I reached for my microphone (in the car), then my iPhone (who knows where), then resigned myself to accepting the fact that my eBird checklist would not be illustrated with sound recordings of those crossbills. I pondered on them for a moment—sharp-sounding, probably Type 3s, or maybe Type 2s? For more on 10 or so “types” of Red Crossbills, see this online primer.
Regardless of what type they were, this represented the first time I’d encountered any kind of Red Crossbill in this area, despite a couple thousand hours spent birding and surveying there.
A little asking around and poking about the internet seemed to confirm it: Red Crossbills were on the move, and not just in the Upper Midwest. The West Coast was also getting in on the action, with quite a few moving south during summer. Numbers in the western Great Lakes really ramped up during July, with Types 2, 3, 4, and 10 recorded; Type 4s in Minnesota and Wisconsin were the first documented in those states. Even more exciting were the first documented occurrences of Type 5 Red Crossbills in the two previously mentioned states; this population is currently regarded as a vagrant east of the Rockies. Some Type 3s and 10s have also been noted in portions of the Northeast U.S., in addition to Type 1s, which appeared to move north from their Appalachian strongholds.
So, where do we stand at this writing? Numbers of Red Crossbills are continuing to march across portions of the continent. But this is both a widespread and unpredictable event, and one where we can use your help in determining when and where these nomads might be passing through. Will they continue pushing south and east through the autumn? The last big flight year, 2012, brought many to the Mid-Atlantic, particularly from October into December. Only time will tell just how extensive this year’s irruption might—or might not—be.
As always, we simply cannot make sense of this year’s event without a collective effort from the birders of North America. If submitting crossbill reports to eBird, be sure to attach any photos and (especially) audio, as recordings of flight calls are the surefire way to determine which type(s) might be involved. And remember, you don’t need a fancy mic to accomplish this! Your smartphone can produce recordings usable for identification. For ID help, consider sending recordings of crossbills to Matt Young at the Cornell Lab of Ornithology (may6 AT cornell.edu). We look forward to covering this year’s crossbill movements in a future issue of North American Birds, but can only do so with your help!
For a more in-depth treatment of the subject and this year’s flight, keep your eyes peeled on the eBird website for an updated Red Crossbill primer from Matt Young and Tim Spahr.
(Thanks to Matt Young and Tim Spahr for contributions to this blog post.)
Note: This is another in a series of blog posts from the editors of North American Birds. The idea of these occasional posts is to highlight ongoing bird population phenomena of broad interest to birders and field ornithologists across the continent. Full analysis will appear in print in North American Birds. To learn more or to subscribe, please go online: http://publications.aba.org/north-american-birds/