Idaho Bird Records Committee Rarities Report Form

Species: Rose-breasted Grosbeak (female)

Reporter: Jay Carlisle

989 W. Sherwood, Boise, ID 83706 jaycarlisle@boisestate.edu

Other Observers: Caroline Poli, Nathan Banfield, and Stephanie Coates (IBO field assistants @ Lucky Peak)

Date Report Prepared: 6/20/10

Date Sighting Occurred: 9/9/09

Locality of Observation: Lucky Peak, Ada Co.

Habitat: mosaic of deciduous shrubs, Douglas-fir forest, and shrub-steppe

Conditions: don’t remember

Did you take notes? No

Did you consult a field guide or other reference work? yes

What guide(s) or reference(s) did you consult? Pyle guide & Sibley

Description: The bird was captured during standardized fall migration banding. The bird had relatively wide streaks that came across the entire chest, orange/salmon-colored wing-linings, a lot of pink on the bill, and a narrow but distinct patch of white on the chin. The bird was an adult based on skull development and symmetric flight feather molt. The wing measured 95mm and the tail 72mm.

Behavior: N/A.

How and when did you positively identify the bird, and what clinched the identification for you? The wide and extensively-placed chest streaks, more extensively pink bill, the white throat patch, and the different-colored wing linings all pointed to Rose-breasted. Another key is that symmetric flight feather molt is normal for adult RB Grosbeaks in late summer/early fall but adult BH Grosbeaks normally wait until after fall migration to begin molting flight feathers.

How did you eliminate similar species, and what were they?

Black-headed Grosbeak females tend to have thinner streaks (that are more restricted to the sides of the chest & flanks), some orange or tawny coloration to the underparts, less of a white throat, and more dark on the bill.

Experience with this species (and similar species):

I’ve seen 100s of each grosbeak species but this is one of only a few Rose-breasteds I have seen in Idaho.

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) Yes – 1 by Caroline Poli in which the bird is shown on left in direct comparison to an immature male Black-headed.

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