In non-weather related news...Holiday activities and preparations for the Boulder Christmas Bird Count continue. Today marks the beginning of 'count week' for Boulder. For anyone new to the Christmas Bird Count concept, the count week incorporates the three days preceding and the three days following the date of the count. Birds recorded within the count circle during count week, but not seen on the actual date of the count can be added to the report which is sent back to Audubon by the count compiler.
In recognition of that, I spent my lunch in Superior - well outside the count circle. I had a couple of quick errands to run in the area, but did want to get out for a bit while the skies were clear and bright. I started at the Singletree Trail, but only caught a few species moving around, Magpies, Juncos, Spotted Towhees, a Raven and a couple of House Finches (above) were the only birds around.
As I drove back through old Superior after getting in my walk I caught an aerial dogfight passing me on the left. Peering around trees and houses I followed the progress of yet another juvenile Cooper's Hawk to a perch behind the firehouse. I circled the block and was able to shoot a couple of frames as it perched on the framing where hoses are dried after use. That perch was not to last though. A pair of American Crows were soon on the scene, chasing the Coop off its perch and into a nearby tree, where all three birds eventually settled down. In the picture below note how similar the Crow and Hawk are in size. Crows are often used as a mental reference for size comparison in the field. Cooper's Hawks are very similar, where Sharp-shinned Hawks would seem smaller, more along the lines of a Robin's size.
I am not sure why I have been seeing so many Cooper's Hawks this December, but they are certainly welcome. This bird offers another good chance to review the field marks for a juvenile of this species. From a distance the size is a solid starting point, and the vertical dark stripes on the breast are a good way to eliminate a juvenile Red-tailed, even when distance makes size tough to judge. From a closer vantage point the light-colored iris is a good indicator of youth across many raptor species. Cornell's Birds of North America Online also indicates that the streaking on a young Cooper's will end higher on the belly than a Sharp-shinned juvenile, but I'll admit I haven't had much of an opportunity to compare juveniles of both.
Our territory group for the CBC are getting the details worked out for Sunday, and hopefully we'll get a chance to compare some Cooper's and Sharpies along the way. I hope to swing by Baseline Reservoir on Saturday as well, as both a White-winged and Black Scoter have been there for over a week, and both would make nice life adds to my list as 2010 winds down.
Hopefully birds and weather will come together for you, wherever you may find yourself birding this weekend.
Great photos of the hawks!
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