On the origin of Dark-eyed Junco subspecies in Ohio

Examining an isolated resident population to learn more about a wintertime favorite

For about half the year, they are Chicago birds. Dark-eyed Juncos are grayish members of the sparrow family that come south to yards, woods, parks and gardens in winter. 

One of the nearest breeding populations of juncos isn’t to the north, though, it’s to the east—in northeast Ohio, in areas just east and south of Cleveland. While these birds don’t move far from their Buckeye State haunts, they’re an interesting lens into the species, which consists of 15 subspecies.

Much of northeast Ohio was logged in the late 19th and early 20th centuries, but a small population of breeding juncos persisted, retreating to hemlock ravines. Now, they are thriving as the forests have replenished. More is known about the population because of a study that’s been under way since 2017 at places like Stebbins Gulch on the property of Holden Arboretum.

That’s where Haans Petruschke comes in. Haans is a researcher for the junco project and helps keep up four study sites, including one in his yard near the arboretum. He teams up with an Arboretum wildlife biologist to set up mist nets, stock feeders and comb through trail camera footage.

I have known Haans since I was in elementary school, as he was the leader of Sunday bird walks at Holden. We spoke this weekend about juncos. Haans had just gotten back from near a study site that had been blocked by heavy snowfall. 

BD: How was it getting to the site?

HP: We were on service roads that are closed off. Something gets blocked, and we’re clearing debris and trees. It’s not the first time we’ve had to do it. 

BD: So I remember juncos there, but not at all in summer.

HP: Our breeding population is the oldest documented breeding population in North America. Jared Kirtland [of Kirtland’s warbler fame] wrote about them in 1838 in his ornithology: “Juncos do breed in the dark beech forest east of Cleveland.” We’re interested in understanding why this breeding population likes it here and in a very limited range in Ohio [the next closest are in the Allegheny Mountains]. They’ve apparently been resident here for a very long time. In the summer we color-band the birds, and in the winter time we have feeders with trail cams, to show that they are year-round residents. And now it’s a more general study of this breeding population, and we have all kinds of questions. 

BD: Why do you think the sub-population exists? Is it the hemlock forest?

HP: What you need for breeding juncos, it doesn’t have to be hemlock. I have beech-maple forest and they like it. They like it if there’s a good source of fresh water, a healthy forest floor and a good herbaceous layer. It might be our soil on the Allegheny Plateau, it’s 10,000 years old. You go down to Canton and all of a sudden the soil is 10 times older. You’ll find hemlocks at places like Mohican [State Park], but you don’t find juncos. That’s my hypothesis, that it has to do with the soil. We don’t know. That’s just an idea.

BD: What might not people know about juncos? 

HP: One of the interesting things about juncos that I didn't realize when I started this is they seem to be on the cusp of speciation. One of the big questions of taxonomy in general is how does a species evolve. What makes a species a distinct species. The northeast Ohio population shows so little plumage dimorphism. Farther north females become more distinctly lighter gray and browner [like Chicago birds]. We didn’t think we’d seen a single female the first two years. 

What we’re constantly amazed about is how smart and aware these birds are. We know them as individuals and not just as another junco. That’s a fun aspect as well. 

We’ll get more into juncos in Friday’s newsletter and talk to Haans about “Doug,” an automated wooden junco he made for the study. 

Great Kiskadee in Illinois is first state record

A one-day wonder turned out to be much more than that.

A Great Kiskadee—the first recorded in Illinois—spent much of this week near Southwest Suburban Channahon. It was first seen on Tuesday by John Weisberger. But intrepid big-year birders (are there any other kind?) Nathan Goldberg and Steve Huggins didn’t stop looking for the brightly hued flycatcher and finally found it again on Saturday.

The news drew observers from all over the region to see a species whose nearest population is in Texas’ Rio Grande Valley and is widespread in Central and South America.

The noisy flycatcher has been hanging around a site called the “Des Plaines Wide Waters,” near where the DuPage River meets the Des Plaines River southwest of Joliet.

Goldberg, who just set the Illinois record for species in a year, had a feeling the bird might still be around since other vagrant kiskadees have stayed in place for at least a few weeks.

The kiskadee was still being seen as recently as yesterday.

TWiB Notes

Chicago Ornithological Society (COS) has set up a neat way to give back, by “adopting” local birds and voting on a Chicago bird of the year. Funds raised support COS’ conservation projects in the Lower North Branch of the Chicago River and in the Calumet Region…..Area Christmas Bird Counts may begin as early as a week from today. Covid-19 has made this a very unusual year for these events, so it’s best to check with compilers as to whether there will be a count in your area. There’s more information here, check the map view of circles and zoom in on the Chicago area. Illinois Ornithological Society has some handy resources also.

Be part of a community of people who share your interest in birds. By becoming a paid subscriber, you join a community where making films like “Monty and Rose” is possible.