American Birding Podcast



HAPPENING NOW: Upslope Sparrows


The other day, I saw 9 Clay-colored Sparrows at Greenlee Wildlife Preserve, my local patch. That Monday morning, May 14, 2018, was raw and cool, with a low cloud deck, steady drizzle, and a bit of fog. It’d been a while, it occurred to me, since my last Clay-color sighting at this postage-stamp preserve in Boulder County, Colorado.

Yup. According to eBird, I hadn’t seen the species there since May 16, 2016. According to my notes in the “Comments” field, the weather that day two years ago was characterized by “Light rain, low cloud ceiling.”

I dug deeper into the eBird database. At this writing, I’ve entered 189 eBird checklists in the month of May, 2007–2018, at Greenlee Wildlife Preserve. Clay-colored Sparrows appear on 19, or 10.1%, of those checklists. We’ll call it 1 in 10, which, if you do the math, would equate to detections of Clay-colored Sparrows 1 or 2 times per May for me at the preserve.

This Clay-colored Sparrow was one of 9 at the writer’s local patch, Greenlee Wildlife Preserve, Boulder County, Colorado, May 14, 2018. The species is missed altogether on ~90% of May visits to the preserve. But if certain meteorological ingredients are in place, the species is practically guaranteed. When it rains, it pours Clay-colors. Photo by © Ted Floyd.

The preceding is correct as a statement about arithmetic means, but it conceals an awful lot of Clay-colored Sparrow migratory biology. Let’s dig deeper still. I saw 0 Clay-colors in May 2007, the first year I eBirded the preserve. I got my first Greenlee Clay-color on May 27, 2008, which, according to my notes, was “drizzly and chilly.” Are you starting to notice a pattern? My next detection was of a mind-blowing 85 on May 11, 2009, on the heels of a major spring storm. Then none in 2010, but 8 on May 16, 2011, a rainy day. I’ll relent now, but I’ll also state the result a bit more formally:

Clay-colored Sparrows never occur in May at Greenlee Wildlife Preserve, except during periods of prolonged “upslope flow” (or “orographic lift”), when they are practically guaranteed.

The obvious next question:



I don’t know. But you know me. That won’t stop me from a bit of idle conjecture. Prolonged upslope flow in Boulder County in May brings winds from the east, and I’m guessing Clay-colored Sparrows, normally migrating to our east, get entrained and sucked westward. Other Midwestern migrants no doubt go along for the ride, but the situation appears to be acute with Clay-colors. They’re tiny, they’re relatively wimpy fliers (technical term, “short-distance migrants”), and their main spring migration corridor is fairly westerly (but east of Boulder County) to begin with.

I’m sure that’s a terribly simplistic explanation, and I suspect I’ll incur the wrath of one or more of Boulder County’s great birder–meteorologists. (Bryan Guarente, Joanie Kleypas, David Dowell, and Peter Gent: Please be merciful, next time I see you in the field.) But I also suspect it’s at least in the right ballpark. And, with a bit of fact-checking and further exploration of the eBird database, I bet it could be a nice little paper:

“Upslope Flow: Orographic Lift Predicts Spring Fallouts of the Clay-colored Sparrow, Spizella pallida, west of I-25 in Colorado,” by T. Floyd

Where to submit?

Why not North American Birds, a journal of ornithological record published by the American Birding Association? Speaking of North American Birds


Publication of North American Birds has fallen behind schedule, and I feel bad about that. On the bright side, I can tell you that North American Birds Editors Mike Hudson and Tom Reed are well along with production of vol. 70, no. 2 of the journal, and that I am doing preliminary work on a combo issue, vol. 70, nos. 3–4. I hope that’s encouraging news, but I also want to put things in perspective.

In this age of eBird and BirdTrax, of #ABARare and @ABABirdAlert, and of every manner of listserv and text alert system, we have come to expect bird news in real time. And not just rarities. A friend in Boulder County specializes in alerting the community to developing phenomena. I’m guessing he was all over this Clay-colored Sparrow fallout the moment he heard that blessed two-word phrase: upslope flow. Come to think of it, he should write the paper for North American Birds. We could run it in that combo issue, vol. 70, nos. 3–4. Or, following the lead of many other journals, we could run a digital version first. Write it today, rapid review tomorrow, revise on Friday, publish on Saturday.

The preceding scenario is fanciful, but not inconceivable. I mean, conceptually, I’ve already put it out there. I had my little Clay-colored Sparrow insight on Monday morning, I asked ABA Blog Manager Nate Swick on Monday afternoon about publishing, I went birding and off the grid on Tuesday morning (more on that below), I drafted the post on Tuesday afternoon, and you’re seeing it now on Wednesday morning. Less than 48 hours from data collection and analysis to review and publication. Wouldn’t it be cool if North American Birds were to become the venue for the digital publication—and eventual print publication—of dozens of such papers each year?

Spring migration sightings of the Gray Flycatcher have surged in the past decade on the plains of northeastern Colorado and southeastern Wyoming. This individual was one of at least 3 at a private ranch in Laramie County, Wyoming, May 15, 2018. Are we witnessing the beginning of a range expansion, as predicted by a recent climate change report by The National Audubon Society? If so, we need analysis of the eBird database—and North American Birds would gladly receive a manuscript on the topic. Photo by © Ted Floyd.

I’m serious. Here in my neck of the woods, all sorts of things are HAPPENING NOW. The Clay-colored Sparrows may have cleared out of Greenlee Wildlife Preserve, but what about all the Gray Flycatchers we’re getting? Gray Flycatchers? Andrew Floyd and I saw at least three on Tuesday morning, May 15, at a private ranch in south-central Laramie County, Wyoming, well out on the High Plains. The species was unheard of there a decade ago.

I suppose I’m in full-on think-outside-the-box mode right now—and why not? We at the American Birding Association are 100% committed to North American Birds. And we are strongly allied with the American Ornithological Society’s admirable mission to “meet the ever-changing needs of ornithology and ornithologists.” Ornithology and ornithologists, not to mention birding and birders, have changed massively in the past several decades, and all are indications are that the pace of change will only accelerate.

Before too long, I’ll be withdrawing from my formal role as Managing Editor of North American Birds. But I’ll continue to support and depend on the journal. I don’t know what North American Birds will look like, but I’m nearly certain that it will look different, drastically different. That’s because the journal’s Editors, along with all of us at the American Birding Association, are committed to delivering a product that is relevant and respected in this age of dramatic and exciting change for birders and ornithologists.

A Brewer’s Sparrow (left) shares a perch with a Clay-colored Sparrow (right), Greenlee Wildlife Preserve, Boulder County, May 14, 2018. Over the decades, birders have largely solved the ID conundrum of separating these two species by plumage. But what about differences in the factors that predict exactly when they occur on spring migration? Do you have insights into the matter? Please consider submitting to North American BirdsPhoto by © Ted Floyd.