Hawks on the rise
Artwork by Chicago-based artist Diana Sudyka.
Editor's note: This episode of the Curious City podcast includes a story about the resurgence of Cooper's Hawks in Chicago. It starts at 4 minutes, 45 seconds into the program. (Subscribe via iTunes or Feedburner!)
This story about hawks was a long time coming for Carole Zemont of Chicago’s Norwood Park neighborhood. Carole thinks she’s “genetically predisposed” to be interested in birds, after growing up watching them at the bird feeder her mother put up in their backyard.
That lifelong interest — as well as a recent hawk sighting of hers — led Carole to ask Curious City:
Is anybody studying the increasing hawk activity in Chicago’s neighborhoods?
Her question covers several topics, including the people on the lookout for hawks, but we thought we owed it to Carole to suss out whether — in fact — there’s a local population of hawks on the rise. While tracking this down, we came across a bit of a wildlife conservation success story.
(Chicken) hawks on the increase
Observant bird-watchers like Carole suspect there are more hawks in the area, but have professional researchers taken note, too?
Well, there are several local researchers who study and document the goings-on of wild critters in our urban and suburban environment, but when it comes to studying hawks specifically, we can turn up only one: Mason Fidino of the Urban Wildlife Institute. Founded in 2009, the Institute’s part of Chicago’s Lincoln Park Zoo.
For the first part of Carole’s question, does Fidino’s work show that there is an increased hawk population in Chicago? “Yes! It’s a pretty resounding yes,” he says. Fidino is recreating a historic bird count that was conducted in Lincoln Park from 1897 to 1903, and he’s able to compare current bird populations with this century-old data. One hawk in particular stands out in Fidino’s studies: the Cooper’s Hawk, which he describes as the “most abundant,” frequently seen bird of prey in Lincoln Park. This is quite a change from the historic study, where the Cooper’s Hawk “was not seen whatsoever.”
These birds were once widely viewed as a menace and even hunted in the past. Nicknamed “chicken hawks,” they were despised as chicken thieves.
Fidino points me to the historical record, where we can find sentiments from people like Alfred O. Gross, a man who eventually became a respected ornithologist. In 1906 Gross conducted a bird census in Illinois. He described the Cooper’s Hawk as a “handsome robber” with a “perverted taste for chicken.”
Later, the pesticide DDT also damaged their population. Cooper’s Hawks mostly eat other birds, so they would have ingested all of the DDT concentrated in their prey animals. The pesticide caused eggshells to thin, and they would crack under the weight of the large birds. The Cooper’s Hawk was even on Illinois’ endangered species list from 1977 through 1997.
Eventually, human interference loosened: We stopped shooting “chicken hawks,” we banned DDT, and, according to Fidino, the hawks came back.
How easy is it to see one?
Mason Fidino says you can find hawks in the city if you look for them —especially Cooper’s Hawks. “Often enough you’ll see hawks circling around,” he says, adding you can also spot them perched on tree branches. Fidino advises curious residents to “spend some time on a weekend, take a walk out in a park. You should be able to see a bird of prey or two.”
Fidino says he sometimes even sees hawks hunting in Chicago’s Lincoln Park. If you see something quickly zooming towards the ground, it could be a hawk looking for lunch. For his part, Fidino will see the hunting bird just out of the corner of his eye. It will be “this really quick movement going from the top of the tree downwards to whatever it’s trying to catch. Then its talons go out, and it grabs what it’s going after and then it’ll swing back up or land with it,” he says.
Cooper’s Hawks have nests that are smaller than squirrels’ bulky, leafy nests. Another way to catch a glimpse of a hawk is to keep an eye on their nest “and see who shows up,” Fidino says.
A possible hawk menace?
It’s reassuring to see a previously struggling species thrive, but perhaps you’re wondering about a downside. Cooper’s Hawks survive mostly by hunting smaller birds. Will we be hearing about a “save the chickadees” campaign in a few years?
Fidino is not worried. Populations of top predators like hawks tend to be much smaller than their prey species. The relatively few chickadees or pigeons who end up being a hawk’s lunch shouldn’t significantly damage their population. The various bird populations, Fidino says, “should be able to work themselves out into what you’d kind of consider an equilibrium.”
Hawks mostly hunt birds, although they’ll also dine on small mammals. It’s very rare for pets to come under attack by raptors. However, when pressed, Fidino will advise that owners of small pets might want to “be mindful of the species that they’re adding to the ecosystem,” and perhaps not leave especially tiny dogs unattended in the back yard.
The adaptation game
Carole wondered if we’re seeing more hawks in Chicago because they’ve developed adaptive behaviors to live in cities. Dr. Seth Magle, the Urban Wildlife Institute’s director, says that’s not the case. He described the concept of “habitat analogs,” where parts of our built environment function to animals the way their natural habitat does.
Magle provides the example of pigeons. “They’re cliff-dwelling species, but in cities we build these big tall buildings, so to pigeons they may kind of look like cliffs,” and thus look like home, he says.
Hawk behavior is similar. Red-tailed hawks like to perch on something tall, and power lines along the highway function perfectly for that task. Other species, including the Cooper’s Hawk, feel perfectly at home in trees near humans. And why not, now that we city-dwellers and suburbanites are more interested in watching hawks than shooting them.
Special thanks to the Cornell Lab of Ornithology for permission to use images, bird listings and sound for this story.
Katie Klocksin is an independent producer. Follow her on Twitter at @KatieKlocksin.