Sighting Record for Utah

Common name:	Connecticut Warbler
Scientific name:	Oporornis agilis
Date:	10/7/23
Time:	7:50 am
Length of time observed:	30 min
Number:	1
Age:	Immature, hatch year
Sex:	Unknown (could be female, but I've been told its best to leave this unsexed)
Location:	Rio Mesa Field Station
County:	Grand
Latilong:	38.7992853,-109.2046978
Elevation:	1280 m
Distance to bird:	In hand
Optical equipment:
Weather:	Sunny, clear
Light Conditions:	Great, sunny
Description: Size of bird:	Wing 70 mm, tail 44 mm, expose culmen 11.4 mm
(Description:) Basic Shape:	Warbler
(Description:) Overall Pattern:	Yellow, olive
(Description:) Bill Type:	Insectivore
(Description:) Field Marks and Identifying Characteristics:	Hatch Year bird (FCF), possible female but best to leave unsexed. Yellow throat, brownish-yellowish-olivish head and back, and long projection of undertail coverts, nearly to the end of the tail. The primary coverts contrast with the greater coverts and are not as yellow as they would be in an adult. The a1 feather, the carpal covert, and the gr covs are all a rich olive-yellow, while the pp covs and the remiges are a more brown-yellow. Measurements taken: wing chord 70mm, tail 44mm, exposed culmen 11.4mm; and wing minus tail 26mm. (see photos)
Song or call & method of delivery:
Behavior:
Habitat:	Riparian habitat along the Dolores River; shrubby, scrubby vegetation with tamarisk trees and other plants.
Similar species and how were they eliminated:	The long projection of the undertail coverts, nearly to the end of tail, helped differentiate from MacGillivray's or Mourning Warbler. The eye-ring was complete, distinct, and a bold white, separating from the incomplete eye-ring of MacGillivray's. It had a yellower underside than immature common yellowthroat (plus a different plumage and the eye-ring again), and no supercilliary line or breast streaking as in Orange-crowned Warbler. Additionally, the wing length and wing-tail measurements helped key this individual as CONW, and it received a band size of 1, which is larger than we place on MGWA.
Previous experience with this & similar species:	I have seen this species once before, 13 years ago in NC. I have seen and held countless MacGillivray's Warblers and Common Yellowthroat here in Utah, and seen a number of Mourning Warblers in the eastern U.S.
References consulted:	Pyle guide, Sibley 2nd edition, and Blaine Carnes
Description from:	Notes taken at the time of the sighting From photo(s) taken at the time of the sighting
Observer:	Kyle Kittelberger
Observer's address:	370 E Kensington Ave
Observer's e-mail address:	**
Other observers who independently identified this bird:	Malcolm Conner, Caroline Wolfe-Merritt. David Blount, Atoosa Samani, Tim Anderton, Jenna Simkins, Stephanie Weems, Flavio Mota, and Rose An were also present.
Date prepared:	10/9/23
Additional material:	Photos I have many pictures that I can provide, though I have also uploaded some key ones to the eBird checklist
Additional comments:	https://ebird.org/checklist/S151660832