Pickaway Plains and staging swallows

A juvenile Cliff Swallow rockets past my position. No art shot here, just the best that I could do in the fading light.

I spent a wonderful day in Shawnee State Forest in southern Ohio, botanizing and showing Ohio State University researcher Shauna Weyrauch a Bobcat den that I stumbled upon last November. You can read about that and see pics of the mother cat and her two kittens RIGHT HERE. Shauna conducts research into Bobcats and is particularly interested in dens.

On my way home, late in the day, I headed up State Route 104, which parallels the Scioto River on its west side. Beginning just north of Chillicothe in Ross County, I began noticing large numbers of swallows foraging over the fields. Their numbers did not diminish as I moved north, and finally, I saw a field especially thick with swallows and some Common Nighthawks at the village of Yellowbud in northern Ross County. That's about nine miles north of where I started seeing significant numbers of swallows.

As I drove, I could see that many of the swallows were Cliff Swallows, so I wanted to stop and watch a big group for a while to try and see what the species composition and their ratios were. The field I chose was a good one, with many hundreds of birds and this was just a fraction of the numbers that I had seen driving north. And once I left this field, near dusk, I continued to see scores of swallows for a few miles more to the north, to about the latitude of Circleville in Pickaway County.

At my sample site, Cliff Swallow was the most numerous species, followed by Bank Swallow. I'd estimate that these two species comprised 85-90% of all the swallows. Barn Swallow was third most common, and the rest of the birds were much smaller numbers of Northern Rough-winged and Tree swallows, and Purple Martin. In sum, I would estimate that I saw 3,000 Cliff Swallows, 2,000+ Bank Swallows, maybe 1,000 Barn Swallows and perhaps a few hundred of the other species combined.

The area where the swallows were is known as the Pickaway Plains, a prairie that stretched along the Scioto River from about present-day Circleville south into northern Ross County. Its extent is imperfectly known as this prairie was destroyed early on and there seems to be little solid documentation of the Pickaway Plains. Historically, the region is probably best known for the substantial Indian towns within the plains.

The numbers of Cliff Swallows are significant. Bruce Peterjohn, in his The Birds of Ohio (2001), notes the largest fall flocks at 100-150+ birds, with most flocks comprising 15-30+ birds. The flock that I was watching in the one field contained far more birds than that, and in the 12 mile or so stretch of Route 104 where the birds were concentrated there were, as stated previously, far more.

This is the fourth time that I've seen huge numbers of Cliff Swallows in the Pickaway Plains. All of the other observations were made on the opposite (east) side of the Scioto River, in an area called Charlie's Pond, and one at a wetland complex just south of Circleville. The first time, about 12 years ago, I saw an estimated 2,000 Cliff Swallows, mostly resting atop soybean plants. I was with Bernie Master the second time, about 5-6 years ago, and we saw 1,500+ in a tight concentration. Then, in 2020, I saw another group of about 2,500 Cliff Swallows. All of these observations were in the last two weeks of August. I'm going to try and get back down there within the next few days, earlier in the day, and see what I can find. I'd bet that if I had had time to get over to the east side of the river yesterday and explore those other locales, I would have seen far more Cliff Swallows.

As all these areas of Cliff Swallow sightings correspond with the former Pickaway Plains prairie, I have to wonder if this is an ancestral staging area for swallows in autumnal migration. Back in the prairie days, this huge landscape would have been dominated by prairie vegetation that spawned legions of flying insects and would have been a highly productive waystation for insect-eating birds of open country like swallows.