CROW Case of the Week: Cooper's Hawk (#18-3731)

A Cooper’s hawk (Accipiter cooperii) is a medium-sized hawk that is about the size of a crow. Like many other birds of prey, males are generally smaller than females. Both genders do have long tails and small but strongly hooked bills. 

An adult Cooper’s hawk has reddish eyes compared to a juvenile’s yellow eyes. Adults also have more mature upperparts with reddish-barred chests in contrast to juveniles’ brown upperparts and brownstreaking, white underparts. 

Cooper’s hawks sport a flap-flap-glide flight pattern, not a consistent flapping sequence. The wing beats become more aggressive if this hawk is in pursuit of prey. This hawk doesn’t mind crashing through tree branches in pursuit of birds, its primary source of food. In fact, Copper’s hawks are not known to be fish-eaters. They prefer mourning doves, jays, robins, pigeons or game birds such as grouse, pheasants and quail. While smaller birds are usually not targeted, the so-called chicken hawk does attack small mammals like mice, squirrels or chipmunks, rabbit and bats. 

At CROW, an adult Cooper’s hawk was admitted to the clinic from Cape Coral on September 20. The finder reportedly discovered the hawk on the ground in his backyard. Its wings had been splayed for more than 12 hours. When the patient arrived at the clinic, it received diagnostic tests including an intake exam, radiographs and blood work. The intake exam did not reveal any obvious signs of trauma, but the hawk was a bit thin, dehydrated and unable to stand. X-rays did not show any broken bones or other abnormalities. Blood work was noted to be within normal limits, which was said to reduce the chance that toxicity, such as rodenticide, was the issue. 


While red tide poisoning was not totally ruled out, it does seem unlikely, according to Dr. Malka Spektor, CROW veterinary intern. 

“No testing was done to look for brevetoxicosis, but it would be extremely unlikely because Cooper’s hawks eat birds and small mammals, not fish or shellfish,” she said shortly after the patient’s intake. “It is still on the list of possibilities, but very low down.” 

CROW medical officials believe that the hawk possibly experienced some kind of trauma, leaving it temporarily stunned. It was given fluids, started on a re-feeding plan and given some time to rest. It was reassessed daily for further neurological symptoms. 

“Wild birds are very good at hiding signs of pain or injury as a survival mechanism,” said Dr. Spektor. “As far as visual signs of trauma, if they are there, we generally find them through thorough physical examination and radiographs. Generally, a patient that is temporarily stunned will recover within 24 to 48 hours. The patient has shown neurologic improvement, and is now using its feet more than it was on intake. No other neurologic symptoms have developed.” 

After more tests, medical treatment and rest during the weekend, the patient appears to be doing much better. “Based on the diagnostics, we were able to eliminate a number of potential causes. It is most likely that the hawk sustained some swelling near its spine as the result of a trauma, such as a window strike. As the swelling reduced, it was able to regain function of its legs,” said Dr. Spektor. “After the weekend, the hawk has shown great improvement and is not only standing, but is also flying. It will likely be released in the next couple of days.”

UPDATE: The hawk was successfully released after spending a little over a week in care at the CROW Clinic.


CROW Case of the Week stories are written by Bob Petcher and appear weekly in the Island Sun and River Weekly Newspapers.

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