Idaho Bird Records Committee Rarities Report Form

Species: Red-shouldered Hawk

Reporter: Jay Carlisle

989 W Sherwood #306D, Boise, ID 83706; jaycarlisle@boisestate.edu

Other Observers: Heidi Ware & Gary Robinson

Date Report Prepared: 6-20-10

Date Sighting Occurred: 10-25-08

Locality of Observation: CJ Strike Reservoir, Jack’s Creek WMA, Owyhee Co.

Habitat: a large patch of Russian Olive on the SE side of the reservoir surrounded by cropfields and near an extensive riparian/marsh ecosystem where the Bruneau River enters the reservoir

Conditions: I don’t remember exactly but a warm October day

Did you take notes? no

Did you consult a field guide or other reference work? After the observation.

What guide(s) or reference(s) did you consult?

‘Hawks in Flight’ by Dunne, Sibley, and Sutton; Sibley & National Geographic

Description: We were approaching the far SE corner of the olives (we were mostly searching for sparrows or owls) when a large-ish raptor flushed and flew along an old 2-track that runs along the S side of this olive grove. B/c my search image was for owls, it took a moment to shift gears and realize it was a hawk. Then my first impression was of an immature Northern Goshawk b/c of the medium to large size and the rapid flapping. It began to circle up and we could then make out pale crescents formed by pale portions of the inner part of the outermost primaries as well as a rapid flap & glide pattern that the bird used to get lift. The bird was in good lighting when it first flushed and we could see that it was brownish overall on the back and whitish underneath. The bird was backlit by the time it started to circle up so it was hard to make out streaks or any pattern on the undersides. But, we could see the brownish tail with many narrow light bands. Also, once it started circling, I could observe the typical Buteo shape with long, rectangular wings and a medium length tail.

I will note that I was not able to make out any reddish coloration on the bird and that immature birds of the elegans subspecies (California) typically show more obvious black in the wings/tail and reddish areas on the shoulders. This made me wonder about an eastern subspecies but since the bird quickly became backlit, I don’t feel confident about this.

Behavior: The bird was flushed by our approach and then circled up to gain altitude and flew NE in the direction of the extensive marsh area.

How and when did you positively identify the bird, and what clinched the identification for you? Though it took me a moment to get my bearings, the combination of the rapid flapping behavior, the pale crescent-shaped patches in outer wings, and size (smaller than the average Red-tail) all led towards the ID.

How did you eliminate similar species, and what were they? Possibilities include Red-tailed Hawk, Swainson’s Hawk, Broad-winged Hawk, and Northern Goshawk but the rapid flapping behavior and size led me to quickly rule out everything but the goshawk. Northern Goshawk, possibly most similar in size to Red-shouldered Hawk, has a longer tail (never with white bands) and a distinct pale supercilium in all plumages. And, although immature Red-tails will show a generally square-shaped pale panel in the outer primaries, neither the Goshawk or Red-tail show a crescent-shaped panel in the primaries.

Experience with this species (and similar species): I have seen well over 100 Red-shouldered Hawks in many US states (CT, CA, SD, ID, etc.) as well as in Mexico and have seen several in Idaho previously. I have observed many thousands of the other above-mentioned Buteo species all across the US (western/central US for Swainson’s) and in Latin America and I have observed hundreds of Northern Goshawks in many states and in all seasons. This was Heidi’s first Red-shouldered Hawk and one of just a few for Gary.

General birding experience: extensive; 14+ years in US and Latin America

Were photo(s), video, and/or audio obtained by you? (If yes, please include or attach) No.