Rare Bird Report #:  84-B-06

 

Idaho Bird Records Committee Rarities Report Form

 

Species: Tennessee Warbler

 

Reporter: Jay Carlisle

6105 Kirkwood Rd

Boise, ID 83709

jaycarlisle@boisestate.edu

 

Other Observers: Joselynn Plank, Emily Stoddard, Casey Richart

 

Date Report Prepared: 12-11-06

 

Date Sighting Occurred:  8-31-01 (capture)

 

Locality of Observation: Lucky Peak (Boise Foothills), Ada Co.

 

Habitat: montane deciduous shrubland bordered by coniferous forest

 

Conditions: I do not remember

 

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’, National Geographic

 

Description: A small Vermivora warbler with a slender bill; a bright yellowish/greenish back and head; a distinct, dark eye-line splitting a broken eye-ring; a yellow wash on the throat, upper chest, and flanks; whitish undertail coverts and belly; and a relatively short tail (as compared to similar appearing Vermivora warblers like Orange-crowned).  Wing: 60mm; Tail: 43mm.

 

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

 

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

 

How and when did you positively identify the bird, and what clinched the identification for you?  Clinching features included the whitish undertail coverts, bright greenish-yellow coloration to back and head, and the dark eye-line. Additionally, the relatively short tail was another diagnostic field mark.

 

How did you eliminate similar species, and what were they? Orange-crowned Warbler (always has yellow undertail) is the most likely to be confused with this species, especially for immature Tennessee Warblers which are a brighter yellow than all subspecies of Orange-crowned.  However, the combination of the features mentioned in the above section all help to separate from Orange-crowned and other Vermivora species.  Additionally, Orange-crowned Warblers have a longer tail and an Orange-crowned Warbler with a 60mm wing is most likely to have a tail measuring 49 or 50 mm (as opposed to 43mm).

 

Experience with this species (and similar species): I have observed many hundreds, if not thousands, of each during migration and winter in both the US (especially South Dakota for Tennessee) and Mexico (Orange-crowned) and Central America (Tennessee).  I have also captured and several immature and 2 adult (1 male & 1 female) Tennessee during fall migration at Lucky Peak and Camas NWR along with well over 1000 individuals of Orange-crowned Warbler 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 Joselynn Plank.  One is a close-up. Two others are comparison shots: 1 showing the Tennessee with a Nashville and an Orange-crowned and the 2^nd showing the Tennessee with 2 Orange-crowned – one brighter one and a dull one (possibly of 2 different subspecies).