A Thanksgiving Bird: Cooper’s Hawk

Probably Cooper’s Hawk
Probably Cooper’s Hawk
Probably Cooper’s Hawk

On Thanksgiving day, I walked right under this bird and didn’t see it until some folks on a side path stopped and pointed to the owl box along the northern leg of the paved perimeter trail.  There it sat, on top of the box, ignoring the humans below.  The cloudy afternoon and the late hour — 4:20 pm is nearly sunset these days — prevented a really clear, sharp portrait of this predator.  It was clearly a hawk of some kind, but it was smaller than the Red-tailed Hawk or the Red-Shouldered Hawk we’ve seen in and around the park from time to time.  And it had those big very red eyes.  I had to go home and get on the web to ID this bird, and I landed square in one of the classic birder dilemmas: distinguishing a Cooper’s Hawk from a Sharp-shinned Hawk.  Weighing all the clues, I’m putting my two cents here on Cooper’s Hawk.  It has the squat body, big head, dark cap and raised feathers on the back of the head that are typical of Cooper’s.  When a large group of walkers approached, the bird took off and flew to the next owl box to the east, where it sat until it got bored and flew off into the scrubby hillside.  This is a new bird to me, a small Thanksgiving gift from Mother Nature, for which I’m grateful. 

The Cornell bird lab website has these “Cool Facts” about Cooper’s Hawks:

  • Dashing through vegetation to catch birds is a dangerous lifestyle. In a study of more than 300 Cooper’s Hawk skeletons, 23 percent showed old, healed-over fractures in the bones of the chest, especially of the furcula, or wishbone.
  • A Cooper’s Hawk captures a bird with its feet and kills it by repeated squeezing. Falcons tend to kill their prey by biting it, but Cooper’s Hawks hold their catch away from the body until it dies. They’ve even been known to drown their prey, holding a bird underwater until it stopped moving.
  • Once thought averse to towns and cities, Cooper’s Hawks are now fairly common urban and suburban birds. Some studies show their numbers are actually higher in towns than in their natural habitat, forests. Cities provide plenty of Rock Pigeon and Mourning Dove prey. Though one study in Arizona found a downside to the high-dove diet: Cooper’s Hawk nestlings suffered from a parasitic disease they acquired from eating dove meat.
  • Life is tricky for male Cooper’s Hawks. As in most hawks, males are significantly smaller than their mates. The danger is that female Cooper’s Hawks specialize in eating medium-sized birds. Males tend to be submissive to females and to listen out for reassuring call notes the females make when they’re willing to be approached. Males build the nest, then provide nearly all the food to females and young over the next 90 days before the young fledge.
  • The oldest recorded Cooper’s Hawk was a male and at least 20 years, 4 months old. He had been banded in California in 1986, and was found in Washington in 2006.

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