The Hawks in Your Backyard

Biologists scale city trees to bag a surprisingly urban species, the Cooper's Hawk

  • By Eric Wagner
  • Smithsonian.com, August 23, 2011, Subscribe
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Bob Rosenfield with Coopers hawks
Bob Rosenfield holds a pair of Cooper’s hawks in a city park in Victoria, Canada. The female, in the foreground, is a third again as large as her mate. (Eric Wagner)

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Bob Rosenfield stares up into the high canopy of a Douglas fir in Joanie Wenman’s backyard, in the suburbs of Victoria, British Columbia. “Where’s the nest again?” he asks.

“It’s the dark spot near the top, about 100 feet or so up,” says Andy Stewart. “The first good branch is around 70 feet,” he adds helpfully.

“All right!” Rosenfield says. “Let’s go get the kids.” He straps on a pair of steel spurs and hefts a coil of thick rope. Hugging the tree—his arms barely reach a third of the way around it—he starts to climb, and soon falls into a labored rhythm: chunk-chunk as the spurs bite into the furrowed bark; gaze up; scout a route; feel for a grip with his fingertips; hug the trunk, chunk-chunk. Those of us pacing beneath listen to him grunt and huff. As he nears the nest, the female Cooper’s hawk dives at him with an increasing, screeching fervor: kak-kak-kak-kak-kak!

“Woah!” Rosenfield yells. “Boy, she’s mad!”

“Man, I hate watching him do this,” Stewart mutters. Most people, he says (his tone implies he means most “sane” people), would use a climbing lanyard or some other safety device should they, say, get thumped on the head by an irate Cooper’s hawk and lose their grip and fall. “But not Bob.”

At last, Rosenfield reaches the nest. “We got four chicks!” he calls down. “Two males, two females!” He rounds them up (“C’mere, you!”) and puts them in an old backpack. He uses the rope to lower the chicks to the ground. Stewart gathers up the backpack and takes the chicks to a large stump. They are about 19 days old, judging by the hint of mature feathers emerging from their down. He weighs them, measures the lengths of their various appendages and draws a little blood for DNA typing.

Meanwhile, Rosenfield stays in the canopy, gazing off into the middle distance. After the chicks have been hoisted back to the nest, I ask Stewart what Rosenfield does while he waits. “I don’t know for sure,” Stewart says. He chuckles. “I think he likes to watch the hawks fly underneath him.”

Rosenfield, a biologist at the University of Wisconsin, Stevens Point, has been free-climbing absurdly tall trees in pursuit of Cooper’s hawks for more than 30 years. Cooper’s hawks are about the size of a crow, although females are a third again as large as males, a size disparity apparent even in chicks. The sexes otherwise look alike, with a slate back, piercing red eyes and russet-streaked breast, the exact color of which varies with geography. Rosenfield has worked with other, perhaps more superficially impressive species in more superficially impressive places—gyrfalcons in Alaska, peregrine falcons in Greenland. But even though he’s most likely to study Cooper’s hawks in a city, he has a special fondness for them. “They’re addicting,” he says. “DNA really outdid itself when it figured out how to make a Cooper’s hawk.”

Not everyone thinks so. With their short, rounded wings and long tail, Cooper’s hawks are well adapted to zip and dodge through tangled branches and thick underbrush in pursuit of prey. They occasionally eat small mammals, like chipmunks or rats, but their preferred quarry is birds. Cooper’s hawks were the original chicken hawks, so called by American colonists because of their taste for unattended poultry. Now they are more likely to offend by snatching a songbird from a backyard birdfeeder, and feelings can be raw. After a local newspaper ran a story about the Victoria project, Stewart received a letter detailing the Cooper’s hawk’s many sins. “Two pages,” he says. “Front and back.”


Bob Rosenfield stares up into the high canopy of a Douglas fir in Joanie Wenman’s backyard, in the suburbs of Victoria, British Columbia. “Where’s the nest again?” he asks.

“It’s the dark spot near the top, about 100 feet or so up,” says Andy Stewart. “The first good branch is around 70 feet,” he adds helpfully.

“All right!” Rosenfield says. “Let’s go get the kids.” He straps on a pair of steel spurs and hefts a coil of thick rope. Hugging the tree—his arms barely reach a third of the way around it—he starts to climb, and soon falls into a labored rhythm: chunk-chunk as the spurs bite into the furrowed bark; gaze up; scout a route; feel for a grip with his fingertips; hug the trunk, chunk-chunk. Those of us pacing beneath listen to him grunt and huff. As he nears the nest, the female Cooper’s hawk dives at him with an increasing, screeching fervor: kak-kak-kak-kak-kak!

“Woah!” Rosenfield yells. “Boy, she’s mad!”

“Man, I hate watching him do this,” Stewart mutters. Most people, he says (his tone implies he means most “sane” people), would use a climbing lanyard or some other safety device should they, say, get thumped on the head by an irate Cooper’s hawk and lose their grip and fall. “But not Bob.”

At last, Rosenfield reaches the nest. “We got four chicks!” he calls down. “Two males, two females!” He rounds them up (“C’mere, you!”) and puts them in an old backpack. He uses the rope to lower the chicks to the ground. Stewart gathers up the backpack and takes the chicks to a large stump. They are about 19 days old, judging by the hint of mature feathers emerging from their down. He weighs them, measures the lengths of their various appendages and draws a little blood for DNA typing.

Meanwhile, Rosenfield stays in the canopy, gazing off into the middle distance. After the chicks have been hoisted back to the nest, I ask Stewart what Rosenfield does while he waits. “I don’t know for sure,” Stewart says. He chuckles. “I think he likes to watch the hawks fly underneath him.”

Rosenfield, a biologist at the University of Wisconsin, Stevens Point, has been free-climbing absurdly tall trees in pursuit of Cooper’s hawks for more than 30 years. Cooper’s hawks are about the size of a crow, although females are a third again as large as males, a size disparity apparent even in chicks. The sexes otherwise look alike, with a slate back, piercing red eyes and russet-streaked breast, the exact color of which varies with geography. Rosenfield has worked with other, perhaps more superficially impressive species in more superficially impressive places—gyrfalcons in Alaska, peregrine falcons in Greenland. But even though he’s most likely to study Cooper’s hawks in a city, he has a special fondness for them. “They’re addicting,” he says. “DNA really outdid itself when it figured out how to make a Cooper’s hawk.”

Not everyone thinks so. With their short, rounded wings and long tail, Cooper’s hawks are well adapted to zip and dodge through tangled branches and thick underbrush in pursuit of prey. They occasionally eat small mammals, like chipmunks or rats, but their preferred quarry is birds. Cooper’s hawks were the original chicken hawks, so called by American colonists because of their taste for unattended poultry. Now they are more likely to offend by snatching a songbird from a backyard birdfeeder, and feelings can be raw. After a local newspaper ran a story about the Victoria project, Stewart received a letter detailing the Cooper’s hawk’s many sins. “Two pages,” he says. “Front and back.”

Due in part to such antipathy, Cooper’s hawks were heavily persecuted in the past. Before 1940, some researchers estimate, as many as half of all first-year birds were shot. In the eastern United States, leg bands from hawks that had been shot were returned to wildlife managers at rates higher than those of ducks, “and it’s legal to hunt those,” Rosenfield says. Heavy pesticide use in the 1940s and ’50s likely led to eggshell thinning, which further depleted populations. On top of that, much of the birds’ forest habitat was lost to logging and development. The species’ predicament was thought so dire that, in 1974, National Geographic published an article asking, “Can the Cooper’s Hawk Survive?”

It was this worry that brought Rosenfield to Cooper’s hawks in 1980, in Wisconsin, when the state listed the species as threatened. “They had a bit of a conundrum on their hands,” Rosenfield says. Once a species is listed, the state has to put in place a plan for its recovery. “How do you call a bird recovered if you don’t know how many there are in the first place?” he says. So he went in search of them. First, he looked in places they were supposed to be: in mixed forests, or next to rivers. But he started to hear about hawks in odd places. There were reports of them nesting in towns and cities, in places like Milwaukee. If so, their habits were not in keeping with conventional raptor natural history.

As he heard from more colleagues around North America, Rosenfield expanded his study and confirmed that Cooper’s hawks are thriving in urban areas. He now works with populations in Stevens Point, as well as Albuquerque, New Mexico and Victoria, where the hawks were first detected in 1995. He goes to each place for a week or so each summer to catch adults and band chicks with local biologists. (Stewart, who himself has studied Cooper’s hawks yards for 17 years, is a retired biologist formerly with the British Columbia Ministry of the Environment.) More often than not, the people he and his colleagues visit not only invite them to conduct research on their property, but they also take an active interest in the birds’ welfare. “It’s good PR for the hawks,” Rosenfield says. “People get to see them up close, and then maybe they hate them a little less.”

In cities, Rosenfield has found, Cooper’s hawks can take advantage of a near bottomless supply of pigeons, sparrows and starlings. Unlike other species that stray into cities, Cooper’s hawks are as likely to survive there as in more natural habitats, and pairs produce similar numbers of chicks. “We’re seeing some of the highest nesting densities in cities,” Rosenfield says. Not only that, cities may be one of the best options for the long-term viability of the species. In Victoria, Cooper’s hawk populations are stable. In Milwaukee, their numbers are increasing rapidly.

In the end, Rosenfield suspects that Cooper’s hawks may not have been so rare after all. It may just be that people weren’t going to the right places. They sought them in forests and mountains, when really all they needed to do was go to their own backyards and look up.

The next day, we go back to the Douglas fir behind Joanie Wenman’s house. This time Rosenfield is going for the chick’s parents. He sets up a 12-foot-high fine-mesh “mist net,” concealing it among firs and big leaf maples. He and Stewart tether a long-suffering captive barred owl to a stand a few feet from the net—Cooper’s hawks hate barred owls—and place a speaker beneath it. In the early years, Rosenfield tells me, trapping the adult hawks was hard. “We had to do so much to hide the nets,” he says. “Because Coops have eyes like—well, you know.”

We retreat as the speaker blasts out different renditions of Cooper’s hawk distress calls. After a few minutes, we hear a series of kaks. “There she is,” Stewart whispers. We look and see the female glowering at the owl from a branch 50 feet above it. She kaks again, and then dives, steep and swift. The owl flails off its perch as the hawk sweeps over its head and slams into the net. “Got her!” Rosenfield yells. He sprints over to the hawk as she thrashes, thoroughly trussing herself, and carefully extracts her. He hands her off to Stewart, who takes her vitals as Wenman watches, asking the occasional question about the hawk’s biology.

When Stewart is finished, he gives the female to Rosenfield. “Aren’t you something,” Rosenfield says. He holds her out, appraises her, strokes her back. The female glares at him. “Hey, want to hear something cool?” he asks Wenman. He moves the female toward her head. Wenman jerks back. “Don’t worry,” Rosenfield laughs. “It’ll be fine!” Wenman does not look entirely convinced, but she makes herself stand still. Rosenfield gently brings the female toward her again, Wenman flinches—she can’t help it—but Rosenfield nods encouragingly as he presses the bird’s chest to Wenman’s ear. Wenman cocks her head, hears the hawk’s wild thudding heart. Her eyes widen at strength of the sound, and she smiles.

Eric Wagner has written about cranes in the Korean Peninsula’s demilitarized zone and penguins in Punta Tombo, Argentina.

Next: The path from devastation to recovery »


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Comments (26)

There is no organization or indndividual that know more of Northern goshawk migration, habitat, and distribution than what I know. And every bit of my knowledge has been garned only by me, with zero help fron the Smithsonian Institute!
All field guides need to be modified to show the true habitat, distribution, and migration of Northern goshawks. If the population of Northern goshawks increases dramatically, and if they can begin breeding in cities and suburbs, then you will observe a huge decrease in the populations of Cooper's Hawks, at least in cities and suburbs. As northern Goshawks have been moving into cities and suburbs, and have been doing so for many years! Nelson Briefer- Goshawk Specialist- Anacortes, WA. Please heed.

Posted by Nelson Briefer on November 18,2011 | 06:08 PM

I enjoyed reading the aricle from Bob Rosenfield about Cooper's Hawks. I live in an inland valley of southern California and I have Cooper's Hawks in my yard most every day. I have four bird feeders which attract many House finches, a favorite food of the Cooper's Hawks. I have watched birds for years and feel strongly that the Hawks play an important ecological niche in maintaining healthy populations of songbirds. I find 4 or 5 dead house finches a week in my yard which simply die from old age or disease. The Cooper's Haawks take these weak birds and, as a consequence, the flock remains healthy and strong.
I am a big fan of Cooper's Hawks. They are a magnificent accipiter and deserve our respect.
Thanks, Bob, for your efforts to help these wonderful birds of prey.

Posted by Joe Castino on October 28,2011 | 02:30 PM

I raise pigions in Chico Ca. In late October the coopers migrate down from the North. I lose about half a dozen a year to coopers. There have been time during the Winter where I have witnessed 4 0r 5 attacks a day on my pigeons.
Today it happened again , the cooper came out of the sky and hit one of my birds hard knocking many feathers from it. I have seen this many times but I'm amazed that many times after the pigeon has been hit hard it still escapes. After a few attacks the pigeons stay in the coop. I have also had coopers get in the pigeon coop and were unable to find their way out. I had to catch them to release them from the coop.

Posted by Michael Teply on October 17,2011 | 07:41 PM

Don't see any Coopers Hawks at my home in metro Atlanta, but a whole family of Red Shouldered Hawks have lived in the neighborhood for years.

Posted by Ken on October 10,2011 | 08:41 AM

We live in a large, established neighborhood in the urban Columbia, SC area. We see Cooper's hawks frequently. Several times we had them flying low near our bird feeder. Once we saw one eating it's kill right outside our bathroom window. Quite gruesome, but majestic all the same. There has been a great upswing in the number of hawks just recently in SC. We' ve also had a red tailed in our yard. He sat in a tall pine for an hour or more.

Posted by Sandy Osborne on September 29,2011 | 09:58 AM

We have a Cooper's Hawk that comes to visit our backyard feeders. It is fantastic to see him sitting atop the feeders. We haven't seen him catch any prey yet, but we have found evidence of his hunting with piles of feathers appearing on certain mornings.

Thanks for a fascinating article.

Posted by Larry Neumann on September 28,2011 | 02:44 PM

My family and I had the opportunity to see a Cooper's hawk in action. First, he attempted to hunt some sparrows in one of our neighbor's trees but they proved too quick for him. We saw him fly away after the failed hunt. But, about 5 mins later he silently glided into another tree where several squirrels live. We stood under the tree and watched him hunt down one of the squirrels. It was one of the most amazing things I've seen. I wasn't aware that hawks hunted like that until I saw him (or her). I looked up the bird on the Internet and have been a fan ever since!!! We see him (or her) fly over our yard about once a week and have even begun calling him Coop!

Posted by Kristina Campbell on September 27,2011 | 05:26 PM

We live in an inner suburb of St. Louis also. Our tiny fish pond has attracted many possum and racoons(who eat the fish!)several wild turkeys, one redtailed hawk, and finally one Cooper's Hawk.Cool bird-never saw one before, didn't know there were any around.

Posted by jim shanahan on September 25,2011 | 05:30 PM

During my walks along the irrigation ditches in Albuquerque's South Valley, I see Cooper's all the time. A half block from my house a pair raised four chicks to adulthood and it was great to see all six of them perched on telephone wires and a pole as a group portrait. They had no fear of me. I got within five feet of one and he never moved. I saw a male come out of the trees, fly 75 yards very fast, and nail a Eurasian collared dove on the ground. And one day I saw a black-chinned hummingbird chasing a female.

Posted by Dave DeWitt on September 23,2011 | 05:03 PM

I live in an inner ring suburb of St. Louis and last winter I saw a Cooper's hawk try get a starling on my deck. That starling got away. Unlike a lot of people, I would not be happy to see a starling get eaten but I accept it's nature's way. I just acquired my second pet starling yesterday - she's sitting on my arm right now. If you get to know starlings they are not only sweet birds but very smart and interesting too. They do just about everything a pet parrot does - play with toys, learn tricks, talk - except most of them don't like to be petted. If anyone is curious about pet starlings or talking starlings do some searches and you'll find out some interesting things.

Posted by Carolyn Hasenfratz on September 19,2011 | 09:55 AM

I also have a mating pair that reside in my backyard. I have only seen them hunt for birds, their favorite seems to be doves. It is incredible that such large birds are so agile and can easily navigate through tangled trees at such a high rate of speed. I may be crazy, but it seems that they hunt in pairs. One will flush the birds out while the other captures them. They had babies this year and it was incredible to listen to them. They are extremely interested in what I or my dogs are doing. They will sit and watch for quite some time. Luckily, so far all of my chickens have been safe!

Posted by Kat on September 18,2011 | 04:50 PM

My sister, who is also my neighbor, and our families enjoyed watching a pair of Cooper's Hawks nesting in one of our neighbor's backyard trees over the summer. Around the same time, a cardinal had discovered himself in an old mirror we'd left leaning against a little shed outside. Like clockwork, the little cardinal would come to that mirror every 15 minutes to admire himself. We enjoyed watching him for weeks. Then we went on vacation for 5 days. When we returned, my sister said the Cooper's Hawk had eaten our cardinal. It really put things into perspective.

Posted by Karen Riggins on September 17,2011 | 04:09 PM

I guess the Cooper's Hawk is all over the country. We have a nest in the top of a Cypress tree in our back yard in Ft. Lauderdale, FL. Watched the two chicks in training this summer with the mother, learning to fly and hunt. Fasinating!

Posted by Alfred Latimer on September 16,2011 | 07:25 PM

excellent article ~ thank you! we have at least one nesting pair Cooper's hawks here in our New Jersey suburban backyard "woods" and, as my desk faces out to those woods and our half dozen feeders, I've witnessed them taking out at least 4 mourning doves. Unbelievably fast, unbelievably lethal. It was very impressive. The squirrels barely have time to scramble out of the way.

Posted by Karen L Mertens on September 16,2011 | 02:05 PM

I had Bob as a professor at UWSP and his class was fantastic! I went into the class thinking it was going to be boring and ended the semester absolutely in love with birds. I now work full time with birds of prey in a zoo in Minnesota.

Posted by Julie on September 9,2011 | 06:45 PM

So, Bob Rosenfield spikes his way up those trees? Hardly good current arborist practice. He really should be setting ropes & climbing with them. (One shoots up a thin line and uses it to pull up the climbing line.)

The spikes damage the bark, and are not good for the tree. He would probably say that one person going up and down once isn't a lot, true enough, but it's something.

So if they run into some *tree-hugging* birders, they'll get an ear-full!

Posted by Arthur Shippee on September 3,2011 | 06:05 PM

The University of Minnesota raptor center took in more Cooper's hawks than Red-tail patients last year. That is telling us something about this versatile species.

Posted by Karen Carroll on September 3,2011 | 11:28 AM

For years we've been watching Coopers maneuver around through the dense shrubs under our bird feeders in Colchester CT. It's an amazing site. We see Red Tails and Red Shouldered also, but they can only land on a tree branch above the feeders and watch the birds that have taken cover in the forsythias and yews.

Posted by Lynn on September 2,2011 | 10:45 AM

My neighbor, Rich and I enjoy frequent glimpses of our resident Cooper's Hawk here in the Chicago suburbs. We often call each other's cell phones upon hearing or seeing one of our favorite birds such as the hawks or falcons. I first noticed our resident hawk when a decapitated pigeon almost fell on me from high up an ash tree. Thought the predator was a kestrel at first until I saw how much larger this bird was; very exciting.

After reading this excellent article, I had to send Rich a link to it and I brought up the idea of taking up a new hobby beside bird watching and photography. Just think two sixty plus year old guys free climbing trees to get better pictures! He wasn't as keen on the idea as I was; not surprisingly he is the smarter one of us. Keep up the good work, my family enjoys every issue of Smithsonian!

Posted by Claude Schlecker on September 2,2011 | 06:17 AM

We have Cooper's Hawks near Houston Texas. They have taught us a whole new meaning to the term "bird feeder", but the one I saw best sat outside my kitchen window eating a rat for 20 minutes. I only hoped he had not found it in my yard.

Posted by Susan on September 1,2011 | 05:48 PM

We have many Cooper's hawks around our area and many hunt on or near our property in NJ. Very sadly, a few years ago, there was a beautiful female who injured her wing and was seeking protection under our deck. We were able to capture her with a blanket and placed her in a large carton with water for the night. We took her to the Raptor Trust the next morning. Unfortunately, they decided her injury was too severe and she was put down. They did tell us that she was young and that wing injuries are common because of the speed at which they fly and manuver through thick forested areas. They also told us that of all hawk species, Cooper's hawks simply do not adapt to life in captivity. We also learned many are found to have multiple healed chest fractures from impact as well. Truly a gorgeous hawk to see up close.

Posted by Christina on September 1,2011 | 02:29 PM

Here in Tucson, AZ we have had Cooper's in our backyard for almost 10 years. We have seen several generations on a regular basis. They usually catch doves, which we have plenty of, or pigeons from surrounding apartment buildings. I have seen them go after squirrels, but their main diet is birds. We are starting to see them sooner in the year now. They used to appear in early fall(Oct. Nov.) but this year they started sitting in the trees in Aug. We have to make sure we look up whenever we go outside, or be surprised by the flap of wings as we get to close. I love them. They are good parents, fierce about territory and beautiful.

Posted by Sheri Owens on September 1,2011 | 12:07 PM

I live in San Jose, CA, where there is a very well-known nesting pair of peregrine falcons that live at City Hall! The nest can be viewed online at http://www2.ucsc.edu/scpbrg/nestcamSJ.htm

I have never seen a Cooper's hawk hereabouts, but redtails soar above my neighborhood (a residential area near downtown San Jose) frequently, and I have seen a merlin in hot pursuit of a blue jay fly right through my backyard at eye level! (The jay got away by dint of some of the most spectacular flying I have ever seen…)

I have never understood the prejudice against raptors, and I applaud the efforts of these researchers to protect these amazing birds.

Posted by Gary K. McCormick on September 1,2011 | 11:57 AM

Bob is my colleague here at UWSP and I commend Eric for capturing Bob's greatest talent; teaching. I've seen him net Coops with a group of students, and to see Bob with a hawk in hand surrounded by his students is to see Bob in his natural habitat Wonderful article.

Posted by Christopher Yahnke on August 29,2011 | 12:35 PM

Thanks to your pictures and article, I think we have Cooper hawks at my place in Mashpee, Cape Cod.

Posted by lorraine johnson on August 24,2011 | 02:34 PM

Great article!
I've sighted several Cooper's Hawk in my backyard(in Northern Virginia) over the past 3 years. I began to notice them when I kept a birdfeeder filled for songbirds. I have seen a Cooper's Hawk kill at least 4-5 birds and I'm sure many more were killed when I wasn't watching. It is strangely thrilling to watch even though it is grotesque. I've only seen them kill the obnoxious Starlings, blackbirds, or common House Sparrow. It would not be thrilling to watch if I ever saw them catch a Cardinal, Robin, or some other sweet songbird. But it is how nature works.

Posted by Kathy on August 24,2011 | 12:33 PM



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