Cooper’s Hawk

Over a century ago, birds of prey were near-universally reviled because of their overstated roles in killing domestic poultry and game species, and from this the Cooper’s Hawk earned the nickname “chicken hawk.” They were shot indiscriminately across a large portion of the east and didn’t receive widespread legal protection until the 1960s. At the same time, they were being negatively affected by persistent organic pesticides like DDT, which reduced reproductive success just like it did in high profile species like Bald Eagle and Peregrine Falcon. As a result, Cooper’s Hawk was listed as threatened or endangered in many states, including New Hampshire. After DDT was banned, populations rebounded much more quickly than those of other affected raptors, and the chicken hawk managed to get off the threatened list with no other help from us. As it recovered, it also began to change its behavior, and adapted to urban and suburban landscapes. Now it’s generally believed that Cooper’s Hawks are the most abundant backyard raptor in the United States.

No discussion of the Cooper’s Hawk would be complete without mentioning the challenges in identification. The “accipiter” hawks are notorious in this regard, especially in their immature plumages. Size can be helpful, but because males are much smaller than females our three species overlap significantly. Sharp-shinned Hawk is the smallest, and the males are quite tiny indeed – weighing less than a Mourning Dove. At the other extreme (leaving the massive goshawk out of the discussion) a female Cooper’s is the size of a crow. There’s actually no overlap in weight between the two species, but this is hard assess this in the field, and in linear measurements the female Sharp-shinned is only marginally smaller than the male Cooper’s. There’s not space here for an exhaustive treatment (check your field guide!), but a good starting point is the shape of the tail. In Sharp-shinned Hawks all the tail feathers are roughly the same length, giving the tail a squared-off look (or slightly notched when perched). In contrast, the tail feathers of a Cooper’s get shorter away from the center and give a rounded appearance.