Rare Bird Report #: 73-B-06

Idaho Bird Records Committee Rarities Report Form

Species: Black-throated Blue Warbler

Reporter: Jay Carlisle (I did not see bird – verified through photos)

6105 Kirkwood Rd

Boise, ID 83709

jaycarlisle@boisestate.edu

Other Observers: Caroline Poli, Stephanie Eyes, Erin Kiely, Chad Merkley (all IBO field crew members)

Date Report Prepared: 9-27-06

Date Sighting Occurred: 9-11-06 (capture)

Locality of Observation: Camas NWR headquarters, Jefferson Co.

Habitat: riparian woodland

Conditions: clear, light breeze

Did you take notes? not at all

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

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

Pyle’s 1997 ‘The Identification Guide to North American Birds’, Sibley, National Geographic

Description: A Dendroica warbler with dusky greenish upperparts; a white wing patch at the base of the outer primaries that extends past primary coverts; light underparts (yellowish-white); a prominent whitish supercilium; dark auriculars; and brownish flight feathers. Wing: 61mm; Tail: 50mm.

Based on incomplete skull development and plumage, this bird was identified as an immature (hatch-year) female.

Behavior: none observed as this was a bird captured as part of a standardized bird migration study at 930am

How and when did you positively identify the bird, and what clinched the identification for you? The bird was captured and ID’d by the crew listed above whereas I identified the bird after viewing the attached photo. Clinching features included the pale supercilium, white wing patch, dark auriculars, and greenish coloration to back and head.

How did you eliminate similar species, and what were they? Given a good look at this species, such as in-hand, the ID is straightforward as no other warblers or small greenish birds combine a pale supercilium and dark auriculars with the white in the wing. However, some possible similarities might include Orange-crowned Warbler (more yellowish than green, no wing patch, and with yellowish below), Ruby-crowned Kinglet (wing bars, tiny), or Tennessee Warbler (brighter green back, short tail, no wing patch).

Experience with this species (and similar species): The crew listed above had little to no prior experience with this species, though Caroline had seen them back east. However, they were quick to make this straightforward ID once the bird was in-hand.

I personally have observed moderate numbers (> 50) during breeding, migration and winter in both the US (esp. Connecticut, South Dakota, Wisconsin, and Minnesota) and Jamaica. I have also previously captured and banded 2 Black-throated Blues (1 adult female, 1 immature male) during fall migration at Lucky Peak (see separate reports, in preparation).

General birding experience: moderate for the crew listed above as each has several years of field/birding experience

Were photo(s), video, and/or audio obtained by you? (If yes, please include or attach)

Yes, but not by me. See attached photo taken by Erin Kiely.