The broad brown wings and barred plumage and short broad tail made identifying the type of bird straight-forward. Almost all respondents identified this species as a raptor (the guess of Brown Pelican was insightful). Identifying the species was harder.

The broad wing tips eliminate falcons. So, then, Eagle? Buteo? Harrier? Owl?

Before we go too far, let's examine exactly what we see. The upper parts seem to be a flat brown with darker bars on the flight feathers. The primaries have very long "fingers." The tail is paler with dark bars. The wing is mostly white underneath, again with visible barring on all the flight feathers. The outer primaries are dark from below, while the inner primaries and base of outer primaries are paler, creating a hint of a white wing patch. The secondaries are darker. There is one obvious patch of dark feathers at the bend of the under wing. The vent, belly, and at least the lower chest is pure white. As for shape, the bird is long-winged and short-tailed.

Could this bird be an owl? Of the owls, the only ones with large dark patches on the bend of the under wing are the Long-eared and Short-eared Owls. In fact, when I first saw this photo, it was Short-eared Owl that I wanted to make sure and eliminate from my first guess. However, these birds show a buffy or rufous patch at the base of the upper primaries, and the fingers would never be that prominent. Both species of these owls should show some streak on the underparts.

Neither Bald nor Golden Eagle have such strong barring on the wings or tail. Both have at least some dark markings on the belly.

Northern Harriers can fool you if you don't get a good look. But this bird clearly does not have a white rump.

In the West we are very used to the wide variety of plumage in Red-tailed Hawk--and juveniles have barred tails, not red. Could this be a Red-tailed Hawk, then? One of the things we look for on the underwing of Red-tailed Hawk is the dark patagial--the leading edge of the wing. But looking carefully at the quiz bird, we see that this dark mark isn't on the patagial--we can't see that inner part of the wing. Rather, this is a dark patch at the bend of wing--the wrist. Now, this alone doesn't eliminate every Red-tailed Hawk, just the light phase birds. That's too bad, because the intermediate and dark phase birds have dark bellies. Even the light phase birds usually have a dark belly band. In fact, finding a bird with this much dark at the bend of the wing, and a totally unmarked belly is problematical.

Worse, there is something wrong with the wings. They are much too long and thin for a Buteo! How do you prove that? While most birds have 9 or 10 primaries, the number of secondaries varies. Most songbirds have 9 secondaries. Longer-winged birds have more (albatrosses up to 40), shorter-winged species less (hummingbirds 6). I count about 20 secondaries on this bird. I count about 12-13 secondaries on photos of Red-tailed Hawks. Thus, this bird has much longer wings than Red-tailed Hawk or other Buteo.

The only raptor with unmarked white belly, dark wrist, and 20 secondaries is Osprey. This Osprey was photographed by Vernon DiPietro in July 2007 at Sauvie Island, Oregon.

Guesses:
Red-tailed Hawk 22
Osprey 15
Rough-legged Hawk 3
Golden Eagle 2
Short-eared Owl 1
Brown Pelican 1
Northern Harrier 1
Prairie Falcon 1

Correct responses, in order received:

Lois Miller, Port Orford, OR
Shawneen Finnegan, Portland, OR
Russ Namitz, Coos Bay, OR
Robert Lockett, Portland, OR
David Fix, Bayside, CA
Craig Bennett, La Grande, OR
Darin Rhein, Newberg, OR
Christine Sheridan, Sherwood, OR
Jeff Marks, Portland, OR
Laura Whittmore, Portland, OR
Stephen Holt, Coos Bay, OR
Chris Warren, Portland, OR
Kristina Gifford, Portland, OR
Mark Thoni, Rancho Santa Margarita, CA
Mary Ann P, Hillsboro, OR