Record #: 74-B-06  

Idaho Bird Records Committee Rarities Report Form

Species: Chestnut-sided Warbler

Reporter: Jay Carlisle

6105 Kirkwood Rd

Boise, ID 83709

jaycarlisle@boisestate.edu

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

Date Report Prepared: 9-20-06

Date Sighting Occurred: 8-22-06 (capture)

Locality of Observation: Camas NWR, Jefferson Co.

Habitat: riparian woodland

Conditions: partly cloudy and light N 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 small Dendroica warbler with white spots in a dark tail; a bright greenish back and crown; grayish face and auriculars; and whitish below with several chestnut-colored feathers on the flanks. Wing 65mm and tail 58mm.

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

Behavior: This was a bird captured as part of a standardized bird migration study at 1000am on 8-22-06. At around 730am the following morning (8-23-06), I observed the bird foraging about 40’ high in a cottonwood tree about 250m east of its original capture location. It was found within a large mixed-flock including many other species of warblers.

How and when did you positively identify the bird, and what clinched the identification for you? Chad originally identified the bird after extracting it from the net and I confirmed identification soon thereafter. Clinching features included bright greenish coloration to back and crown, gray cheeks, the whitish tail spots, and the few chestnut feathers along the flanks.

How did you eliminate similar species, and what were they? Chestnut-sided Warbler is a very straight-forward identification given good views. The combination of gray auriculars, wing bars, the few chestnut feathers, and extensive tail spots eliminate all other warblers with yellowish/greenish upperparts.

Experience with this species (and similar species): I have observed many hundreds, if not thousands, during breeding season, migration and winter in both the US (especially Connecticut and South Dakota) and Central America (especially Panama). I have also previously captured and handled 3 immature Chestnut-sided during fall migration at Lucky Peak and Camas NWR 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, but not by me. See attached photos taken by Erin Kiely.