Sighting Record for Utah

Common name:	Chestnut-sided Warbler
Scientific name:	Setophaga pensylvanica
Date:	05/10/2016
Time:	16:30
Length of time observed:	~10 minutes
Number:	1
Age:	Unknown
Sex:	Unknown
Location:	Birdsong Trail
County:	Weber
Latilong:
Elevation:	4217'
Distance to bird:	15'
Optical equipment:	N/A
Weather:	Sunny/Clear
Light Conditions:	Great
Description: Size of bird:	N/A
(Description:) Basic Shape:	N/A
(Description:) Overall Pattern:	N/A
(Description:) Bill Type:	N/A
(Description:) Field Marks and Identifying Characteristics:	(listen to the audio recording - mp3 version)
Song or call & method of delivery:
Behavior:	Actively singing and moving.
Habitat:	Dense deciduous. Scub Oak, Walnut, Rocky Mtn Maple, Cottonwood, Willow...
Similar species and how were they eliminated:	Having only heard the bird the only form of comparison I had was to eliminate the warblers with the closest songs( Magnolia and Yellow Warblers). The Magnolia's call shorter and the Yellow much longer when listening to their "average" songs. In going through The Warbler Guide vocalizations nothing seemed to match except CSWA. When comparing the sonograms of the 3 the CSWA was a good match.
Previous experience with this & similar species:	Have seen this species multiple times, but prior to this observation was mostly new to its song.
References consulted:
Description from:	The Warbler Guide (iPad app), ibird West (iPad app), the Macaulay Library.
Observer:	Mike Hearell
Observer's address:	173 W 1825 N, North Ogden
Observer's e-mail address:	**
Other observers who independently identified this bird:	None
Date prepared:	5/12/2016
Additional material:	Audio Recording - mp3 version ( comparison - mp3 version )
Additional comments:	When I first heard the song I knew it was one that I wasn't used to hearing. I took a quick recording of the bird's song and then tried to locate the bird. After a couple of minutes passed without seeing or hearing the bird I played back my recording. After getting a good feel for the song I went to the ibird west app on my phone to search through playbacks. The song seemed somewhat familiar to me as I had been trying to brush up on songs lately, and knew it was one I had been trying to familiarize myself with. As I scrolled through the likely candidates Chestnut-sided Warbler was the first one I came to alphabetically. I played its song and immediately could tell I was on the right track. Moments later the bird began singing again 20yards below the trail. I made my way down to the tall Cottonwood that it was singing from and made another recording, but was unable to see the bird. After only 30-45 seconds I watched a warbler sized bird fly from the tree in the direction I had originally heard it. Although I couldn't positively ID the bird from the brief look, I saw nothing to tell me that it wasn't a CSWA.