Field notes by Cheryl Dykstra, co-editor of Urban Raptors
Monday, May 14, 2018
Cincinnati, Ohio

So happy our grad student Ania is back from Texas, having just finished her spring semester. Today is her second day, and the first day with our new undergrad intern Madison, a sophomore studying Environmental Biology.

At the first nest, we are disappointed to find nothing but nestling feathers on the ground. A predator, probably a raccoon judging from the feathers clinging to the sycamore’s bark, apparently killed the nestlings we saw here yesterday. One of the adults repeatedly flies into the nest carrying a fresh sprig of maple, looks around, then flies off a short distance. It would be anthropomorphizing to say she looks confused by the lack of young, but that’s what it seems like to us.

The second nest is better. As we walk into the back yard, one of the adults dives silently directly over mine and Madison's heads. While I’m walking out to the middle of the yard, she makes two more close passes, coming within about five feet of my head. Interestingly, in more than 20 years of working with red-shouldered hawks, I have never had that happen before. The bird’s aggressive nest defense isn’t really a surprise, as the elderly couple who live here reported that the birds have hit them while they walked in their yard, and now the couple are terrified to go out. Vigorous nest defense against people on the ground isn’t really that common in Cincinnati—maybe 5% of the nests—but it can be troubling, especially when children or the elderly are involved. I put on my climbing helmet and hand one to Madison—I don’t want to risk our intern getting injured on her first day.

It’s a day of firsts. We have a new “toy” we’re eager to try, a high-tech taxidermy owl with “robot guts” that make it turn its head and raise its wings.
We set up an almost-invisible mist net next to the robotic owl in an area of the yard where we hope the hawks will see it. Hawks will often dive at great horned owls, which are significant predators in both suburban and rural areas, and researchers take advantage of this natural behavior when we need to trap them.
We retreat around the corner of the house and the parent hawks immediately began calling, and flying around, and then diving on the owl! They dive several times, more than once hitting the owl and knocking its (detachable) head off. Twice we get one in our net, but each time the bird quickly gets out and flies away. Discouraged, we give up, and move on to the next task. I climb the nest tree, a silver maple, and send the nestlings down to the ground for Ania and Madison to band and take blood samples.
The adults haven’t given up their defense, and one of them hits me hard on the helmet as I wait at the nest. Just once though. Getting hit while climbing is pretty rare too—only 11% of the Cincinnati birds actually strike the climber. Ania shows the nestlings to the landowners, who are sitting safely inside and watching us work through their kitchen window, and they agree the young are cute. Few can resist a baby bird. I return the young to their nest and rappel down. I promise the landowners that I will return in the summer after the young are done using the nest and remove it, in the hopes that maybe the hawks will move somewhere else next year.
After a brief diversion (a swarm of bees in a crabapple tree, something none of us have seen before), we arrive at the third nest of the day.
Here we have a great “set,” the net almost invisible, and more loosely suspended this time. We use the remote to make the owl turn its head and lift its wings and we play a recording of the great horned owl hoots. It takes a little while, but suddenly we see a bird rocketing in from the right. It’s caught!
We run to the net and detangle it. We’re excited that the net has worked, but some of that joy drains away when we realize this is the male we caught and sampled two months ago.
We examine him, weigh him, and let him go. Five minutes later, he’s in the net again. Again we detangle him and let him go. The female is still standing in the nest, watching the activities below. We decide to move on to banding the young.
I climb the nest tree, a lovely white pine, and lower the young to Ania and Madison. I enjoy a comfortable seat on a branch just below the nest, and relax in the slight breeze at 40 feet high. It’s 90 degrees now, so the climbing was hot, sweaty work. The team bands, measures, and weighs the nestlings, and takes a blood sample from each. They send the nestlings back up to me and I snap a quick selfie, and then rappel down.

All in all, it’s been a good day.