After the first sub-zero intrusive air mass, there were several new birds in and around Thoreau's Nine Acre Corner. Here's a young adult Redtail exhibiting the Rough-legged Hawk behavior of daintily grasping the top sprays of an evergreen. This is not uncommon as birds from coniferous areas move into our area.
A second young adult bird, with a red tail but a yellow iris over near Walden Pond. To me, and other Redtail-gaters, the least interesting thing you can say about a bird is, "It's got a red tail; it's an adult."

Our Redtails attain that marker first while the eye color, flight feathers, and belly band continue to mature for a few more years.

At least 5 Redtails in the trees near the NYS game farm in Ithaca. Close-up of the adult dark rufous morph Redtail [a bird of this description has Wintered here for several years now]. My January 21st sighting was the first for this Winter though. Jay and Kevin McGowan have a couple of classic images of this Winter phenomenon online on a Cayuga Bird Club page.

Another interesting [aren't they all], older adult digiscoped near the game farm in Ithaca. Nice dark-eyed individual with a wide belly band sitting maybe half-a-mile from the other Redtail commotion and hundreds of miles from home.

Oh, more Old Testament talk from a recent online post [1/8/04 post to Arlington Birds listserv]: "[W]e now know that some hawks in temperate latitudes tend to remain paired on or in the close vicinity of their breeding territories all year long. Some of our locally breeding Red-tailed Hawks in the greater Boston area and the coastal littoral definitely occupy the same basic territory on a year round basis. This is much more obvious in the mid-Atlantic states."

Obfuscation. The Christmas Count math just doesn't work out to account for the numbers of Redtails present. The adult numbers are often too high to be even mostly 'local' birds. The age classes vary from year to year and within a given Winter.
I like the NFL term "tendencies" to describe the laws and rules of biology as they apply to variability within species and toward speciation:
Gloger's Law is the tendency of races from moist areas to be darker [for Redtails, that's birds from denser coniferous forests];
Bergmann's Rule would be the tendency to have a larger body in a colder climate [but mostly if you don't migrate];
Allen's Law is the tendency to have shorter beaks, wings and legs than others of your species if you're from a colder climate.

More Wintertail images ::::::)