Tuesday, September 3, 2013

A barrel of bullbats

I found myself at the beautiful Caesar's Creek Visitor's Center in Warren County last Sunday, which is owned and managed by the U.S. Army Corps of Engineers. The committee members for the Midwest Native Plant Society were there to plan the 2014 Midwest Native Plant Conference, and it promises to be another doozy. As an aside, we also schemed up and plotted out a one-day butterfly conference to be held next July 12 at this very visitor's center. The center has awesome conference capabilities, and equally good, it sits smack in the middle of oodles of great habitat.

After our meeting, we set off to explore the local prairies, such as the patch of turf above. The fields were absolutely swarming with dragonflies, mostly Common Green Darners, Anax junius, with lesser numbers of Black Saddlebags, Tramea lacera. Inestimable thousands were in the area. Equally conspicuous was one of our coolest birds, the Common Nighthawk, Chordeiles minor, sometimes known as the "Bullbat".

Periodic waves of nighthawks would course low overhead, hunting various buggy fare. We saw dozens, probably well over 200. After our group of people finally disbanded, I headed back to this field and that tower in the distance. I hadn't seen a flight of bullbats like this in some time, and wanted to watch them for a while, and try to make some images. By the time I left, I estimated that I had seen 400-500 birds, and that's probably conservative. I took a back route home, and saw even more birds, and then later heard reports elsewhere from southern and central Ohio of other large groups. The nighthawks were definitely on the move last Sunday.

A pair of Common Nighthawks gambol about the skies over Caesar Creek. These nightjars are supreme aerialists, and adept at snatching insects from the air. Most of the birds that I saw probably bred in northernmost U.S., or more likely Canada. People who know the birds around here think of them as nesting on the gravel rooftops of buildings, which they certainly do (see THIS POST). But the lion's share of nighthawks nest in open barrens, big gravel bars, burned over jack pine flats, and other sparsely vegetated open ground. Their nest is little more than a scrape on the ground, and if all goes well, two nighthawk chicks will be spawned.

Pods of hunting nighthawks would come by in waves, and occasional birds would zag near my perch on the tower. At first, I was shooting them with my 150-500 mm Sigma lens, but found it quite difficult to follow and focus quickly. So after a bit, I switched to a Tamron 70-200 mm lens, which is tack sharp and lightning fast. The birds would sometimes come near enough that even a lens without a lot of pulling power, like the Tamron, was good enough.

But alas, shooting great images of speeding nighthawks is not nearly as easy it may seem. These birds are fast as bullets, and when one would come over the tower, seemingly to check me out, it would really put on a burst of speed and rocket over so quickly I could hardly follow it with the camera. From afar, the flight of a foraging bullbat seems languid; the bird lazily flapping about with occasional bursts of acceleration when prey is spotted. When one is 50 or 100 feet away and coming on strong, it is amazing how rapidly they come and go.

Even though none of my photos will be gracing the cover of National Geographic, I had a good time watching the masses of swirling bullbats. These birds will not tarry; they have a long ways to go. Common Nighthawks are one of the long-distance champion migrants of North American birds. The vast majority of the birds that we see in Ohio will winter in South America, and some of them will get as far south as Argentina.

We're still in the sweet spot for nighthawk migration. Watch for flocks passing overhead towards dusk. They'll be headed due south, and the birds will be stone silent, their loud nasal peents are a sound of spring and summer.



Susan Nash said...

I disrupted my tennis match last week to watch 7-10 night hawks swooping and soaring over the courts! I thought it a very cool sight...the other tennis players, not so much.

Doug Marcum said...

Wow, these images are impressive!!! I know how hard it is to lock a lens on a speeding bird. Great work Jim.

Doug Marcum said...

Wow, these images are impressive!!! I know how hard it is to lock your lens on a speeding bird. Great work Jim!