Harris's Hawk

When we first moved here (a couple of years ago, now), Cooper's Hawks were very common. Scarcely a day would go by that we didn't see one. We frequently saw them catch their prey, mantle it for  few moments, then carry it to a broad horizontal branch in the middle of the back yard and pluck most of its feathers before eating it. They caught mainly Gambel's Quail, less often White-winged Doves (perhaps because those were faster flyers), and an occasional Cooper's would specialize in the Round-tailed
Ground Squirrels, which are very common here. The hawks paid almost no attention to us, so we got to watch them from close up for a good insight into their lives.

Sometimes we would see a dark hawk sitting near the top of a tree. This was the Harris's Hawk. It's quite a handsome bird, black and chocolate brown, with a black band on the tip of the tail, and white all the way around the base of the tail. There's a house across the street from us, and from our angle we could see into its backyard which had some big mesquite trees in it, and a pair of Harris's that may have been nesting in them. The birds never seemed to do anything, so we decided that it was a pretty mild bird compared to the Cooper's. Here's where we were wrong. We had a pair of half-tame Roadrunners  in a tree in our front yard with a nest-full of babies almost ready to fledge. The Harris's had a clear but distant view of the Roadrunners constantly flying in to feed them, and one day ripped through the nest and stole them all.

We suddenly had a good deal more respect for them as predators

 

Recently a Harris's visited us, landing in some trees in our backyard close to our house, and we had our closest view ever. Cheryl got this really nice picture. Look at those long legs and oversized talons, look at that meat-cleaver beak. This bird is built on the plan of a small eagle.

This is when I began patching together a theory. For months now we had scarcely seen a Cooper's Hawk. The horizontal branch on the "plucking" tree no longer seemed to be in use. When a panic suddenly cleared birds out of the bird feeders, if we looked at the top of a tall pine tree on the edge of our lot it was always the Harris's sitting there. I wondered if the Harris's had chased the Cooper's out of our yard. In a  fight, if these fierce birds ever fight with each other, I don't think the Cooper's would stand a chance.

The Harris's doesn't live as openly in front of us as the Cooper's, so we don't know as much about them. For instance with the exception of them robbing the Roadrunner's nest, we have never seen them with prey so we don't know what it is most likely to be. In one source, we read that they prey on small mammals, but have never witnessed that ourselves. We know that Cooper's favor quail, a sumptuous meal worth chasing down, but we have also seen a Cooper's catch a half-grown quail out of the line following its parents.

There is another development. Lately we have seen two Harris's together in our backyard. Are they thinking of nesting here now?

This is probably stretching my theory that the Harris's has driven the Cooper's  out of our yard, but if Harris's indeed prefer mammals, and Cooper's quail, it could be the Harrris's are in a sense preserving quail in our yard, and this year we have noticed that we seem to have more quail than ever, with the young that follow behind them preserving their numbers exceptionally well.

We will watch how this develops.