Sighting Record for Utah

Common name:	Tennessee Warbler
Scientific name:	Oreothlypis peregrina
Date:	10/04/2018
Time:	6:00 PM
Length of time observed:	2 minutes (approx)
Number:	1
Age:	1st fall
Sex:	Unknown
Location:	Royal Oaks Park (along Halfway Wash), near Snow Canyon Pkwy/1400 West in St. George
County:	Washington
Latilong:
Elevation:
Distance to bird:	18 feet
Optical equipment:	Nikon 200-500mm lens, Leupold 10X50 binoculars
Weather:
Light Conditions:	Evening light
Description: Size of bird:	Warbler-size
(Description:) Basic Shape:	(See photos)
(Description:) Overall Pattern:	Uniformly yellow-green (darker above) with pale undertail coverts
(Description:) Bill Type:	Sharp, straight, quite thin and long
(Description:) Field Marks and Identifying Characteristics:	As a crossed the foot bridge at Royal Oaks Park, I glanced behind me and noticed a warbler foraging from a willow branch. This warbler just looked a bit different from nearby orange-crowned warblers, which were abundant in the area. As I looked closer, I was first struck by the pale undertail coverts, which immediately made me think this was a Tennessee warbler. Description: An overall yellow-green warbler, with little contrast between its head and back. Entirely dark yellow-green above, and almost entirely yellow below, except for very pale (almost white) undertail coverts. Inconspicuous narrow, pale wing bars. A thin, pale eyebrow contrasts with a dark eye line below. Dark wingtips. (see photos)
Song or call & method of delivery:	I think this bird was silent. I heard some call notes but I think they were from nearby orange-crowned warblers.
Behavior:	Foraging in a willow tree at about eye-level. It remained in view for 1-2 minutes before it joined a small flock of orange-crowned warblers in thicker vegetation below. I was unable to relocate the bird after this.
Habitat:	Riparian: willows, cottonwoods, tamarisk, etc.
Similar species and how were they eliminated:	Orange-crowned warbler: by far the most similar species. Unlike the reported bird, orange-crowned warblers do not normally show a prominent pale eyebrow that extends from the lores to behind the eye. This is the first point in favor of Tennessee warbler. Orange-crowned warblers usually have a grayish head that contrasts with a yellow-greenish body. First-year Tennessee warblers show very little contrast between their head and back, which is in line with the reported bird. The reported individual shows narrow, pale wing bars, which would be lacking on an orange-crowned warbler. Lastly, orange-crowned warblers have yellow undertail coverts. The undertail coverts of this bird are very pale, which is another point in favor of Tennessee warbler. Other superficially similar species could include female yellow and Wilson's warblers, and perhaps warbling vireos. However, I believe my description above (and especially my photos) more than rules out those species.
Previous experience with this & similar species:	Tennessee warbler: no previous experience Orange-crowned warbler: many previous observations (including the day of this observation)
References consulted:	Sibley Western Field Guide, National Geographic Field Guide, various online resources
Description from:	From memory From photo(s) taken at the time of the sighting
Observer:	Mike Schijf
Observer's address:	354 Vermillion Ave
Observer's e-mail address:	**
Other observers who independently identified this bird:
Date prepared:	10/06/2018
Additional material:	Photos
Additional comments: