Cooper's Hawk

This Cooper's Hawk took my Dad and I by surprise. We were walking on a peaceful trail, looking for birds, when all of a sudden there was this large raptor perched on a log in front of us. The Cooper’s Hawk let us watch it for a while before taking off in a flurry (see the video at the end of this post).

Cooper's Hawks are hunters by nature, birds of prey that hunt other birds (and small mammals, insects, and reptiles).^[1] They thrive on surprise. Stealthy hunters, they fly low and slow, closing in, before shooting out to snatch the unsuspecting prey. Sometimes they sneak along the branches, creeping up before making their attack. They'll even steal birds from nests.

Cooper's Hawks hunt so aggressively that sometimes they whack into branches.^[2] In one study, researchers examining healed broken bones chose to examine them for that reason, along with two other kinds of hawks. Out of the 115 wild Cooper's Hawks studied, over 20% had healed broken pectoral girdle bones. 

In short, they're fierce birds. 

Even bird feeders aren't safe! Cooper's Hawks will stake them out.^[3] On that note, if you notice a Cooper's Hawk using your bird feeder as a hunting ground, the Cornell Lab of Ornithology says to take the feeder in for a few days until the hawk moves on.

Flying is important for how Cooper's Hawks hunt, but it's also important to their romantic life. When they court, they fly slowly, flourishing their flight with dramatic wingbeats.^[1] When it's time to start a family, both parents craft a nest, though the dad works on it more ^[4] The outer structure is made of sticks, and then they make it comfy by adding soft strips of bark.^[1] 

With a new home for the babies, the mom will typically lay up to 5 eggs.^[4] She will do most of the incubating, which takes about a month. Meanwhile, the dad brings her food and incubates the eggs as she eats.^[1]

The dad keeps up his food delivery service once the babies are born.^[1] He'll pass the mom food, who gives it to the babies. It takes about a month for the babies to learn to fly, so for a while, the male is gathering enough food for up to 7 birds (including himself).

Getting fluffy.

We can’t talk about the Cooper’s Hawk without mentioning its lookalike: The Sharp-Shinned Hawk. Take a look at this helpful identification guide from the Cornell Lab's Feeder Watch to see how similar they are.^[5] Identifying them from each other can be tricky since on top of looking similar, they share much of the same range.^[4] (However, does the Cooper's Hawk seem like the kind of bird willing to share a territory? No. It kicks Sharp-shinned Hawks out if it notices them.^[4]) 

One key difference between the birds is size. Cooper’s Hawks are larger than Sharp-Shinned Hawks overall.^[5] But there’s a twist: like Great Horned Owls, the females of both hawks are larger than the males.^{[4, 6]} Female Sharp-shinned Hawks can reach 13.4 inches in length, which is only about an inch shorter than the lower range for the length of a male Cooper's Hawk.^{[7, 8]}

So, if size won't help you identify them, some key features to look for are their tails, legs, and heads.  Cooper's Hawks' tails tend to be rounder, their legs thicker, and the contrast between their head and neck feathers starker.^[5] 

Ultimately, I think this is a Cooper's Hawk since it seems (a) large, (b) to have thick yellow legs, and (c) to have lighter neck feathers than on the top of its head. However, I'll admit that I looked through that identification guide several times before deciding. Take a look to see what you think!

The Details:

Common Name: Cooper's Hawk

Scientific Name: Accipiter cooperii (Even the scientific name sounds fierce!)

Order: Accipitriformes

Family: Accipitridae 

Seen: Resting on a log in a wooded area

Month: February

Range: These birds are found coast to coast in the United States. They can also be found in parts of Canada, Mexico, and Central America.^[9]

Learn More About Cooper's Hawks & Friends:

1. Kaufman, K. (1996). Lives of North American birds. Houghton Mifflin.
2. Roth, A. J., Jones, G. S., & French, T. W. (2002). Incidence of naturally-healed fractures in the pectoral bones of North American accipiters. Journal of  Raptor Research, 36(3), 229-230
3. Cornell Lab of Ornithology. (n.d.). Cooper's Hawk: Overview. All About Birds.
4. Alsop, F. J. (2002). Birds of North America (American ed.). Dorling Kindersley Limited. 
5. Cornell Lab of Ornithology. (n.d.) Sharp-shinned and Cooper's Hawks. Project FeederWatch.
6. Cornell Lab of Ornithology. (n.d.). Great Horned Owl: Overview. All About Birds.
7. Cornell Lab of Ornithology. (n.d.). Cooper's Hawk: Identification. All About Birds.
8. Cornell Lab of Ornithology. (n.d.). Sharp-shinned Hawk: Identification. All About Birds. 
9. Cornell Lab of Ornithology. (n.d.). Cooper's Hawk: Range map. All About Birds.