Sighting Record for Utah

Common name:	Bronzed Cowbird
Scientific name:	Molothrus aeneus
Date:	3 Jan 2026
Time:	1440
Length of time observed:	Brief glimpses, <1 min
Number:	1
Age:	Adult
Sex:	Male
Location:	Ellerbeck Road, Grantsville Area
County:	Tooele
Latilong:	40.6780430, -112.5519152
Elevation:	4,250 ft
Distance to bird:	50 ft
Optical equipment:	8x42 ED Binoculars, Nikon Monarch Fieldscope20-60x82mm, Nikon D5600 w/ Sigma S1 150-600mm lens
Weather:	Mostly sunny, abt 40 degrees F, little to no wind
Light Conditions:	Mostly sunny. Obscured by shadows from brush frequently.
Description: Size of bird:	Very similar to nearby Brewer's Blackbirds
(Description:) Basic Shape:	Stocky, blackbird/icterid
(Description:) Overall Pattern:	Black with blue iridescence on wings
(Description:) Bill Type:	Large, bulky
(Description:) Field Marks and Identifying Characteristics:	I had been stalking a flock of blackbirds in the west Grantsville area for a couple weeks. The flock was feeding near the junction of Ellerbeck Road and SR-138 on January 3, 2026. The area has open range cattle, with a corral located nearby as well as a water tank. The flock was primarily feeding along shoulder of the road but flushed every few minutes to a new area within a .5 mile radius. While observing the flock through my scope I noted one bird which appeared to have a far larger bill than the Brewer's blackbirds or European starling. The bird was near the fenced off industrial section, drinking from a puddle with several Brewer's. The bird appeared to be the same size as the accompanying Brewer's but had a notably different tail. The bird was facing away from me which showed the tail well. I noted a lack of club shape, with the tail thickness being even throughout the entire length. The tail also had a blue tinge which was highlighted dramatically when it caught the light. The remiges also showed a brilliant blue tone which was evident even on the side not facing the sun. The flock once again flushed back to the brush near the highway. I tracked down the flock and continued hunting through them. Constant traffic along Ellerbeck Road drove the birds out into the field, and then back to the shoulder, cyclically for nearly an hour. During a particularly long gap between cars (~2 whole minutes), I was able to get some photos of the birds along the shoulder which all appeared to be BRBL. I noted a few others which rem ained farther out in the pasture / brush and grabbed a couple photos before the flock flushed once again, this time into the industrial area west of the train tracks and out of sight. After returning home and reviewing photos, I found that I did get a photograph of the bird. While somewhat obscured by the weeds it was in, I felt enough field IDs were present to solidify an ID and rule out any other species. The head shape is completely different than a blackbird, notably: Bill and head slope/shape: The bill is huge. Notablynfar wider at the base than any blackbird would have. The bill also tapers relatively quickly in relation to the thickness of the base. Bill appears silver/gray, notably lighter than head. The nasal tufts extend down the upper mandible, and gape line forms in line with iris. The head is notably very 'puffy'. The forehead slope into the supraloral area is visibly bulbous, as is the throat below the bill. The head is thicker than what you would find on a blackbird, with the back of the head / neck appearing to start farther back on the bird than a blackbird would, resulting in a blocky appearance. The puffy, blobby face is already a very distinct shape which is unique to BROC. Eye: The iris color is a dull red. Either male blackbird (BRBL/RUBL) would show a pale yellow iris. A female of either species would be obvious. The eye appears tiny in relation to the head, whereas a blackbird would have a larger-appearing eye in relation to the head. Brown-headed cowbird would have a solid black eye. Body: Limited visibility, but the bird appears to be the same color as head, solid black. A bright blue flash is evident on the upper wing. While not many features can be clearly seen, there is no distinction between the head plumage color and body, effectively ruling out brown-headed cowbird. The blue flash also supports BROC. (see photos, and Drawing)
Song or call & method of delivery:	N/A
Behavior:	Ground foraging in a brushy playa in a pasture utilized by cattle. Stayed on the ground to feed, only taking flight when entire flock flushed due to traffic disturbance. Remained in proximity with flock of BRBL and EUST.
Habitat:	Degraded wetland on the historic high shore of Great Salt Lake. Mixed sagebrush and rabbitbrush heavily trampled by cattle. Watering trough for cattle located a few dozen feet from photographed bird.
Similar species and how were they eliminated:	Brewer's Blackbird - Bill is massive compared to BRBL, and silver in color. Head shape, forehead slope, iris color, tail shape, body color. Rusty Blackbird - Same as BRBL, though a RUBL would be even more obvious. Brown-headed Cowbird - Iris color isn't black. Head shape, bill appears even larger than you'd expect on a BHCO. Head is black, not brown. European Starling - Obvious bill and plumage difference. Common Grackle - Iris color and size of eye, bill length, tail length. Please see analysis in description of field marks for species separation.
Previous experience with this & similar species:	Limited, observed with flock of brown-headed cowbird near Salton Sea, California. I found the species easily distinguishable from other cowbirds by iris color and bill size. Brown-headed cowbird - plenty of experience, local species. Brewer's blackbird - Plenty of experience, local species Rusty blackbird - limited, have not seen one in the field. Aware of facial patterns for both sexes in both plumages, bill size, behavior/gestalt (more horizontal, shorter tail, etc)
References consulted:	Sibley Guide, eBird / Cornell Library
Description from:	Notes taken at the time of the sighting From photo(s) taken at the time of the sighting
Observer:	Patrick McAtee
Observer's address:	247 S 360 W Tooele, Utah 84074
Observer's e-mail address:	**
Other observers who independently identified this bird:	N/A
Date prepared:	1/13/2026
Additional material:	Photos Drawing
Additional comments:	Single photo obtained, will provide original cropped photo along with upscaled version and edited version to highlight physical features. Drawing of bird seen initially through scope will also be provided.