Sunday, November 23, 2014

Birds of Prey

After a dark and rainy day yesterday, I was excited to spend some time on Lake Creek Trail in the sun this morning. I spent about two and a half hours on the trail between the Braes Valley parking lot and the playing fields just beyond the footbridge. The most interesting observations I made were related to birds of prey. Near the second bench on the trail I was standing still, watching and listening. (Lately I've been getting interested in bird alarm calls and how they relate to different disturbances the birds experience, like people walking by or the presence of a predator.) Very close by, I heard the distinctive call of a Cooper's Hawk in the narrow and dense strip of trees between the trail and the creek. I looked for the hawk but couldn't find it. All I could find was a Blue Jay. Then I realized it was the Blue Jay making the call, imitating a Cooper's Hawk. I've heard Blue Jays imitating Red-shouldered Hawks, but never a Cooper's Hawk. There has been a resident pair of Cooper's Hawks in this area for a couple years now, so I'm sure it had plenty opportunity to learn the call. I'll have to research why.

Later on the other side of the footbridge I was watching Song Sparrows, Lincoln's Sparrows, and House Sparrows all in the same binocular view in the creek bed when another bird flew into the view. The sparrows all dove for cover as I saw the grey back of a Sharp-shinned Hawk dive at the bush they were in. The hawk continued up the tributary branch of the creek and flew out of view over the woods. A few minutes later I saw probably the same bird that had circled around and was approaching from the same direction. Watching it fly towards me with my binoculars, I saw another bird below it flying in the same direction. The second bird had pointier wings and I realized it was a falcon. It flew almost right over me and from its streaked breast I recognized it as a Merlin. It dove at one of about 40 Great Tailed Grackles that were in the field beside the trail, missed it, and continued out of view.

All three of these birds of prey specialize in hunting other birds. Cooper's Hawks and Sharp-shinned Hawks have round wings and a long tail for chasing birds through the woods and brush. Merlins have narrow pointed wings and tail for fast flight in the open sky. I had seen a Sharp-shinned Hawk dive at birds in a bush on one side of the trail, then a Merlin dive at a bird in an open field on the other side of the trail, in the space of 10 minutes! Merlins and Sharp-shinned Hawks are winter residents here. A few Cooper's Hawks are here year-round, but more are here in the winter. So in central Texas, winter is a dangerous time for songbirds!

As I returned across the footbridge, this Red-tailed Hawk soared over me, looking for a much wider range of prey in the creek bed.

Red-tailed Hawk

Here's my complete bird list. What a fun morning!

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