Verification of Unusual Sight Record
For Utah

Rec. # 2014-0

Common name:

Blue-headed Vireo

Scientific name: Vireo solitarius
Date: 09-01-2014
Time: 12:30pm
Length of time observed: 5 minutes
Number: 1
Age: ?
Sex: Not an adult male
Location: Garr Ranch, Antelope Island
County: Davis
Elevation: 4200ft
Distance to bird: 5m
Optical equipment: Nikon 10x50 Binoculars
Weather: Sunny,warm-80F
Light Conditions: Excellent
Description:        Size of bird: Small passerine-5.5in
(Description:)       Basic Shape: Small short tail passerine with a horizontal posture
(Description:)  Overall Pattern: Green back,yellow flanks,white belly and throat, with a dark gray head
(Description:)            Bill Type: Short,stout hooked bill of a Vireo
Field Marks and
Identifying Characteristics:
My first impression upon seeing this "Soliary: Vireo was that it was a Blue-headed, because of the darker gray head and amount of yellow and green in the body,so Matt started taking photos as I observed the bird. I've had experience with bright "Solitary" Vireos before and wanted to be cautious and make sure it wasn't a Cassin's. But even in the field it appeared to have a high contrast throat/cheek line and had a darker gray head than I would expect for a Cassin's. Upon review of the photos,and while consulting online articles about the complex, it became clear that this Vireo was a Blue-headed.
Dark gray head contrasting with greenish back
High contrast throat and cheek line
Head a darker shade of gray than typical Cassin's
Lores not contrastingly darker than the rest of the head
(see photos)
Song or call & method of delivery: None heard
Behavior: Methodically moving through a Russian Olive thicket, low to mid canopy.
Habitat: Ranch house on the shore of the Great Salt Lake, with many cultivated planted trees and a spring. Know migrant trap.
Similar species and how
were they eliminated:
That day there were many Cassin's Vireos at the ranch for direct comparison, and none had as dark of a gray head or a sharply delineated cheek line as the bird we saw, and all were duller olive brownish, not the bright green and yellow of this Vireo. Upon examination of the photos we got of both species, the contrasting darker lores of the Cassin's also became apparent, and seems a good field mark to distinguish the two.
Previous experience with
this & similar species:
I've never seen a definite Blue-headed Vireo before, but I've seen many Cassin's Vireos, including at least 9 at the ranch that day, and 2 years ago I had a possible BHVI in the same location.
References consulted: 'The Sibley Guide to Birds'D.A. Sibley 2014,'SOME THOUGHTS ON THE 'SOLITARY VIREO' COMPLEX ' D. Robertson(online article),many online photos of Cassin;s and Blue-headed
Description from: From photo(s) taken at the time of the sighting
Observer: Bryant Olsen
Observer's address: 688 East 700 South #105, SLC, UT 84102
Observer's e-mail address: **
Other observers who independently identified this bird: Matt Pendleton
Date prepared: 09-03-2014
Additional material: Photos