Date: 2/13/18 8:57 am From: <phawk254...> [arlingtonbirds] <arlingtonbirds-noreply...> Subject: [Arlington Birds] Dan's Hawk ID
The hawk in question is a juvenile Red-tailed Hawk, not a Sharp-shinned. Check the two out carefully in a standard field guide and you'll see considerable differences between them. (The typically heavier markings of this juvenile bird might have been responsible for the thought it could be a sharpshin.) Redtails are chunky buteos with a hooded head, light breast and belly, separated by a highly variable belly band. Juveniles/immatures are more heavily marked than the typical adult. They have short, wide tails compared to the much longer, narrower tails of a sharphin or Cooper's Hawk.
Now is the beginning of higher-intensity Red-tailed Hawk pair bonding, especially for year-round residents, which will increasingly be seen perching together on "their" territory. (The smaller of the two is typically the male; the female can be 25% larger.) You also have wintering migrants around, including juveniles. Juveniles have light eyes and usually heavier streaking on the belly band, etc., than adults, and they do not have a redtail. Their tails are light brown above with many narrow slightly darker horizontal bands. Some might be into the first stages of molt into adult plumage, getting a red tail feather or two in early. Migrant Redtails move through the region, or wintering birds leave, primarily in March and early April.
Lorraine Kaplan reported an adult Red-tailed Hawk on the apex of 185 Alewife Brook Parkway this morning. This was almost certainly Buzz, a resident of that area for roughly 18 years, making a statement as to this being part of his territory, even though he has not used a nest within roughly a quarter mile of 185 for more than three years. His mate, Belle, is often in the area, though she has been paying attention to another nest site some distance away. There may also be "interlopers" in the area, looking to establish territories. Thus, one might often see three adult Red-tailed Hawks soaring together in February and March on bright, sunny or windy days (cold is okay). This is likely a bonded pair defending mate and territory from an interloper, who is looking for a place to establish his or her territorial home. (Males typically establish and defend the territory. Females might "flirt" with a territorial male to see if he is interested in bonding with her rather than his "current" mate. That can lead to females challenging each other for the male and his territory.) Territorial Redtails will also rise to challenge Bald Eagles flying through their territory, usually tailing them and even harassing them to escort them out of the area. Juveniles (esp males) do not typically establish breeding territories, and may not actually nest until they are 3-4 years old.