Monday, February 15, 2010

Quiz #336 (2010-1-07) Answer

Click the picture for a larger view.

Answer by Tony Leukering

A raptor in flight from above -- though at least one respondent was concerned by the angle, all respondents got the correct species. The wide wings and short tail, along with various plumage features, should take us immediately to the buteos.

The strong window visible (translucent area in the primaries) indicates that it's either an adult of either Red-shouldered or Ferruginous hawks or a juvenile of one of the following species: Red-shouldered, Broad-winged, Red-tailed, Ferruginous, or Rough-legged. When assessing ID via windows in buteos, the shape of the window is critical. Red-shouldered exhibits a thin crescent that cuts across the bases of the outer primaries and is the odd hawk out.

The windows of Ferruginous and Rough-legged hawks are restricted to the primaries, not extending onto the primary coverts, as in our quiz photo, but extending farther out the wing. Broad-winged's window is a bit more like that of Red-tailed, being shorter or squarer, but doesn't extend onto the primary coverts, as does that of Red-tailed. Broad-winged also shows fewer fingers on the spread wingtip than does our quiz bird.

Well, that means that we've arrived at our answer! I took this picture of a juvenile Red-tailed Hawk at Dinosaur Ridge, Jefferson Co., CO, on 22 April 2006. Harlan's (harlani), western (calurus), and eastern (borealis) subspecies occur here in migration, with westerns and mutts (eastern x western) being the local breeding form. The strong brown tones rule out virtually all Harlan's juvs, but given this view, I cannot determine whether the quiz bird is eastern, western, or a mutt.

One respondent's guess was precluded from being correct for the competition, as it included details directly in the answer that were incorrect (age and subspecies). Please read the competition rules.

Incorrect species provided as answers:
Tundra Swan - 1

Congratulations to the 28 of 28 getting the quiz correct:
John Bissell
Andy Dettling
Robert McNab
Kevin Kerr
Mark Dettling
Peter Burke
Aaron Brees
Chuck Carlson
Margie Joy
Tom Bunker
Su Snyder
George Cresswell
Chris Warren
Al Guarente
Peter Wilkinson
Tom Wilberding
Nick Komar
Joel Such
Ali Iyoob
Joe Bens
Bev Baker
William Velmala
Lori Conrad
Kirk Huffstater
Tyler Bell
Marcel Such
Andrea Smith-Guarente
Thomas Hall
Bryan Guarente
Chishun Kwong

Answer: Red-tailed Hawk