Sighting Record for Utah

Common name:	Rusty Blackbird
Scientific name:	Euphagus carolinus
Date:	Jan 30, 2018
Time:	Noon
Length of time observed:	Bird in a shared scope for 3-4 minutes with both observers getting a couple observations each before mixed flock flushed.
Number:	1
Age:	Adult
Sex:	Male
Location:	Gilmor Livestock, 3200W. 3300N.
County:	Salt Lake
Latilong:
Elevation:	4225 ft
Distance to bird:	85 yards
Optical equipment:	85 mm spotting scope with 20-60x zoom eyepiece
Weather:	Temps in the 50's, light clouds, dry, very mild for January
Light Conditions:	Light clouds but bright; occasional sun
Description: Size of bird:	Medium passerine; same as nearby Brewer's
(Description:) Basic Shape:	Passerine
(Description:) Overall Pattern:	Generally inky black with pale accents on head and wing plumage
(Description:) Bill Type:	Insect-eating; finely pointed; about half the length of the head from front-to-back
(Description:) Field Marks and Identifying Characteristics:	Very dark bird; nearly the same dark glossiness as Brewer's Blackbirds in the flock. Same size and structure as Brewer's. Pale eye, pale supercilium about the same color as the eye. Wing covert/back plumage irregularly edged or tipped with paler color than glossy black body plumage, darker color than eye brow. Could not distinguish tertial edges as the bird was in profile facing south; observers east of bird and tertial edges not easily visible. Did not have the opportunity to study the shape of the bill.
Song or call & method of delivery:	None heard.
Behavior:	Perching in a treetop with a mixed flock of Brewer's, Red-winged and Yellow-headed Blackbirds and starlings; possibly Brown-headed Cowbirds as well. Flushed with the flock 3-4 minutes after being detected. Flock often on the move; landing on the ground in the feedlot or in weed patches; breaking into smaller flocks and landing on power lines or in other trees.
Habitat:	Feedlot and agriculture grassland near a river and large wetland.
Similar species and how were they eliminated:	From Brewer's Blackbird: Review bird's supercilium was bold and startling; nearly the same color as the eye while body and most wing plumage was as glossy-dark as male Brewer's. Exception was wing coverts/back plumage irregularly tipped or stippled with a paler color. Subsequent study of male Brewer's on power lines showed state of wear was virtually uniform glossy dark plumage on all birds. Dark glossy plumage and supercilium also eliminates pale-eyed female Brewer's variant. From all grackle sp.: Review bird was the same size as numerous Brewer's Blackbirds in the same tree top. From other blackbirds, cowbirds and European Starlings: Review bird showed distinct combination of pale eye and supercilium.
Previous experience with this & similar species:	One female Rusty; plenty with comparative blackbirds, grackles and cowbirds except cowbirds rare to Utah.
References consulted:	Sibley, Cornell's Birds of North America species profile
Description from:	Notes made later
Observer:	Kristin Purdy
Observer's address:	Ogden, Utah
Observer's e-mail address:	**
Other observers who independently identified this bird:	Pomera Fronce
Date prepared:	Jan 30, 2018
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