Verification of Unusual Sight Record
For Utah

Rec. # 2006-37

Common name:

Magnolia Warbler

Scientific name: Dendroica magnolia
Date: September 9, 2006
Time: 9:30am
Length of time observed: 1 minute
Number: 1
Age: unknown
Sex: unknown
Location: Parley's Nature Area, near junction of I-80 and 2300 E, [Salt Lake City]
County: Salt Lake
Elevation: lowland riparian
Distance to bird: 10-15 meters
Optical equipment: 8x42 binoculars
Weather: clear
Light Conditions: typical mid-morning light conditions. I was looking north at the bird and the sun was from the east; bird was in the shade of riparian trees during observation
Description:        Size of bird: medium-sized Dendroica. More or less similar in size to accompanying Black-capped Chickadees
(Description:)       Basic Shape: typical shape for a wood-warbler
(Description:)  Overall Pattern: grayish above, yellow breast, with longitudinal streaking below, white wing bars, white tail with broad black tip (as seen from below)
(Description:)            Bill Type: thin insectivore bill, typical wood-warbler type
Field Marks and
Identifying Characteristics:
I was looking through a mixed-species flock containing chickadees and a plumbeous and a warbling vireo, when I noticed a warbler that was generally dark grayish above and yellow below. I kept my binoculars on it and saw a grayish face, white wing bars, and yellow breast, with longitudinal dark streaking on the yellow breast. The bird gave me an immediate general impression of a Magnolia Warbler. While the bird was foraging actively I occasionally saw flashes of white coming from the UPPERSIDE of a generally blackish tail. What really clinched the ID was when I got a great view of the UNDERSIDE of the tail. The UNDERSIDE of the tail was white with a broad black tip (the black region was approximately as long as the tail was wide). I'm not sure on the sex/age of the bird, but based on the amount and intensity of streaking
on the underside, I would guess that it is neither an adult male nor a first fall female.
Song or call & method of delivery: not heard
Behavior: actively gleaning from foliage and moving about from branch to branch in mid-level of tall riparian trees, associating with 2 black-capped chickadees, a plumbeous vireo, and a warbling vireo in a
mixed-species flock.
Habitat: riparian woodland. Cottonwoods, box-elder, etc.
Similar species and how
were they eliminated:
By foraging behavior, posture, and bill shape, goldfinches and other yellowish non-warbler birds are eliminated. The white wing bars and dark grayish-above/yellowish below pattern with breast streaking eliminate many other species of warblers such as Nashville, Wilson's, Yellow, MacGillivray's, etc. The undertail pattern that I observed eliminates all other small yellowish species I am aware of (including vagrants) that might be confused with Magnolia Warbler, including the most similar species in fall, Prairie Warbler. American Redstart also has a similar bicolored undertail, but it is yellow/gray or orange/black, NOT white and black.
Previous experience with
this & similar species:
I just moved to Salt Lake from Michigan in early August. My previous 10 years of birding experience have been in Michigan, where Magnolia Warbler is one of the most common fall migrants. I have seen approximately 25-50 Magnolias per fall for the last 10 years. Many similar species also occur in Michigan as common fall migrants, such as Yellow-rumped Warbler, Cape May Warbler, Black-throated Green Warbler, and Blackburnian Warbler. I am accustomed to confidently identifying Magnolias during fall migration because in Michigan it is necessary to be able to rapidly identify a warbler as "just another Magnolia" while in search of more sought-after species. This is usually accomplished by rapidly assessing overall color of the bird and undertail
References consulted: None, but I recommend consulting Peterson's Warbler field guide, and viewing the last color plate, depicting the underside of the tail of all North American wood-warblers, to see just how distinctive the Magnolia Warbler's undertail is.
Description from: From memory
Observer: David Slager
Observer's address: 1345 University Village, Salt Lake City, UT 84108
Observer's e-mail address:
Other observers who independently identified this bird: none yet
Date prepared: 9/9/06 11:30am
Additional material:  
Additional comments: