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Winchester-Nabu Detective Agency Year Seven: Case File No. 16-328

Cooper's Hawk on a thin tree branch

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Where We Left Off:

In our previous case file, there was a deadly hit and run to investigate.

Hangin’ with Mr. Cooper:

August may primarily be known as a Leo month under the great lion’s Sun sign; however, we’ve had a fair amount of new observations with the aves of the region. The Grumpy Old Man has been doing some of his own surveillance, usually with Oliver by his side, and has spotted some wonderful beasts: bats and hawks.

For this case file, we’ll address a particular hawk visitor—a Cooper’s Hawk.

Cooper's Hawk on a thin tree branch - front and back views with Merlin app ID

For detailed instructions about submitting a report to the state of New Jersey for a witnessed interaction, please see the previous case file 15-327.

Seeing this hawk consistently for about a week made me think about what it must eat. I thought a bird of prey like this would be mostly interested in small mammals like our beloved chipmunks. I haven’t seen the chipmunks in a month and I’m worried. However, The Cook told me that this hawk eats smaller birds. I’m not surprised since eagles will do that too.

Cooper’s Hawks mainly eat birds. Small birds are safer around Cooper’s Hawks than medium-sized birds: studies list European Starlings, Mourning Doves, and Rock Pigeons as common targets along with American Robins, several kinds of jays, Northern Flicker, and quail, pheasants, grouse, and chickens. Cooper’s Hawks sometimes rob nests and also eat chipmunks, hares, mice, squirrels, and bats. Mammals are more common in diets of Cooper’s Hawks in the West. —Cornell

Of those birds listed, the only ones that are not common are grouse and quail. In fact, I would not be surprised if this Cooper’s Hawk has been visiting specifically because it knows there are chickens next door. I’m still concerned about the chipmunks though.

Gus has been sticking by me when I try to get to closer to the hawk for photos. So far, we’ve only had one great day (by my standards because my photos are rarely any good) and that was all because Gus led me up the driveway to trespass and find the exact perfect spot for viewing this visitor.

We had to learn more about it. Who would most likely talk to Gus, Ollie, or myself about this particular bird? Since we’ve lost contact with the Chipmunk Mafia, our next source of information would be the Blue Jay Gang—if they were willing to share information. As previously noted, the Blue Jay Gang has been having its own problems with violence and murder. In one day, Oliver and I found five feathers and then Gus and I found more! It’s been rough for the jays lately, but they get plenty of peanuts and seeds to comfort themselves.

From the balcony, the three of us could hear two blue jays. They had to be close—not farther than Gnome Grove. I took the can of peanuts and tossed a few out. Ollie reached his head through the railing to watch. Gus decided to jump over to the roof. It looked like one of our friends/informants, “Lorry Sheep” Biretta, was in the dying maple tree. I let Oliver do the talking since he has a way with the birds and a softer disposition compared to Gus.

Lorry has been a helpful CI in two previous cases, including the one where I was attacked by the Smoke Shifter. She swooped down from the tree to the grass beneath Oliver’s vantage point.

“Lorry says the bird’s name is Christian Coopershawk. New to this immediate area, but knows his way around,” Oliver said.

“Is it because of the chickens?” I asked and Oliver confirmed that it was the presence of the domesticated Galli attracting this shy, but friendly hawk.

On one our sightings, Gus was distracted by his olfactory sense while I listened attentively to Christian Coopershawk. The pitch of his call was much higher than a red-tailed hawk, almost as if he were a baby hawk crying.

Female Cooper’s hawks have roughly double the number of calls as the male. The female is also louder, with a deeper, harsher voice. —Birdfact

Based on our photographic comparison and input from another user on iNaturalist, he is a juvenile. I didn’t realize it at first. His head and back are not a slate grey yet. It’s possible Christian is a female juvenile, but I haven’t received any input about the sex from other community members. We’ll have to hope the bird continues visiting and allows me to photograph its life. These are the changes the detectives and I will have to look for:

First and foremost, female Cooper’s hawks are much, much larger than males – up to 20% longer and 40% heavier. This is amongst the most pronounced reverse sexual dimorphisms of any bird. Besides size, male and female Cooper’s hawks look similar, though females are more brownish and grayish, and males are often a subtle powder-blue color across the wings and back. —Birdfact

Several weeks ago, all of us thought the rooster disappeared. It had been quiet for at least two weeks. Then we started hearing a rooster again. I believe it was replaced with a younger one because it went through that puberty voice change I clearly noticed when the neighbors first brought home the birds. The rooster sounds also seem to come from various directions. I know sound can play tricks bouncing off surfaces and I’m willing to admit that I may be all wrong about the direction. The fact that it changes direction is what I find peculiar. It’s not from next door specifically close to the house. I swear I’ve heard it cock-a-doodle-doo from the woods.

Case Findings:

With no way to investigate next door, we can’t be certain without a doubt that Christian Coopershawk killed the rooster for food. As of this writing, there have been ten opportunities to photograph the hawk. The observations were sent to the NJDEP tracking system. And still, no chipmunks have resurfaced.

Dates of Documented Sightings 2023:

  • August 3, 8, 9, 11, 13, 17, 18, 20, 22, 23

Case Status: Open


Cooper’s Hawk Life History, all about birds, Cornell Lab of Ornithology (no date) All About Birds. Available at: (Accessed: 09 August 2023).

Female cooper’s hawks (identification guide) (2023) Birdfact. Available at: (Accessed: 09 August 2023).

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