Sharp-shinned Hawk and Cooper's Hawk

Over the past couple weeks I happened to get a couple decent in-flight photos of two species of hawk very difficult to distinguish: Sharp-shinned Hawk and Cooper's Hawk. The first photo is a Sharp-shinned Hawk I photographed flying over Nalle Bunny Run Wildlife Preserve on 1/9/2021. The second is a Cooper's Hawk flying over Lake Creek Trail in northwest Austin on 1/16/2021. The main differences these photos show are the angle of the wings and size of the heads. The Sharp-shinned often holds its wings pitched just a little bit forward and has a smaller head, protruding out in front of the wings less. The Cooper's usually has wings held more straightly out to the sides and has a larger head protruding out in front of the wings more.

So why are these two species so similar?

I can only speculate. They have similar ecological niches, both specializing in hunting other birds in the woods. So they both have broad, rounded wings and long tails. Why such similar plumage? They may have also had a common ancestor, and speciated as two different populations found slightly different specialization.

Posted on 18 de janeiro de 2021, 03:56 PM by mikaelb