Rare Bird Report # / Supplemental information
This information was compiled by:
Cliff Weisse
4125 Beaver Springs Rd.
Island Park, ID, 83429
cliffandlisa@octobersetters.com
On 12/29/2008 I received an email from Bill Schiess that included two photos of a buteo he was seeking an identification for. I identified the bird as a Swainson's Hawk and asked him when the photos were taken. He first told me they were from the last week in November 2008 so I encouraged him to document the sighting. When I asked for a specific date Bill said they were taken on 12/3/08 so I recommend that he submit a report to IBRC.
Field marks that I saw in the photos that I feel confirm the identification of Swainson's Hawk include:
-The overall pattern of the under side of the wing is typical for Swainson's Hawk. Specifically the coverts are pale and the remiges are medium to dark gray with widely spacied fine darker bars.
-The underwings coverts are fairly heavily marked but still appear pale overall. Patagium is pale and no dark "commas" are visible on the primary coverts. A few greater secondary coverts are visible and are barred black and white, again consistent with Swainson's Hawk.
-Upperwing has brown coverts and gray remiges that comtrast darker than the coverts.
-wings are long, narrow and straight edged, lacking bulging secondaries of Red-tailed Hawk. Wing tips are pointed.
-underparts fairly heavily marked with brown or rufous bars. Upper breast is solidly brown.
-Tarsi unfeathered
-Head is gray, malar stripe brown, throat white
-bill is small, smaller than typical for Red-tailed Hawk
-undertail pattern is typical for Swainson's, grayish tan with widely spaced fine darker bars and narrow dark subterminal band.
-body is slender
I can see no field marks that suggest other species. The unfeathered tarsi eliminates Rough-legged and Ferruginous Hawks. Red-tailed Hawks in all plumages have dark patagial spot, blackish "comma" on under primary coverts, paler head that is usually golden on light/intermediate morphs or dark brown on Harlan's but never show a gray head, have wings that are more rounded with bulging secondaries, pale primaries/secondaries from below, and upper wing uniform brown with extensive whitish markings on coverts. Less common species that could occur include Red-shouldered and Broad-winged Hawks. Red-shouldered Hawk in all plumages shows pale crescents across the base of the primaries, which this bird does not have. Broad-winged Hawk has entirely whitish underwings in all plumages including the remiges.
I sent these photos to Travis Rosenbury at the Peregrine Fund and he forwarded them to Bill Clark. The following is the reply Travis received from B. Clark, forwarded to me on 1/5/09: