Sighting Record for Utah

Common name:	Costa's Hummingbird
Scientific name:	Calypte costae
Date:	5/17/26
Time:	3:20pm
Length of time observed:	At least 1 hour
Number:	1
Age:	U
Sex:	M
Location:	Rio Mesa / Bonderman Field Station
County:	Grand
Latilong:	38.79785° N, 109.20742° W
Elevation:	Approximately 4200
Distance to bird:	< 1ft
Optical equipment:	Camera - Canon EOS Rebel T7 with Sigma 100-600mm
Weather:	Partly cloudy
Light Conditions:	Partly cloudy
Description: Size of bird:	About the size of BCHU, maybe slightly smaller
(Description:) Basic Shape:	Hummingbird shaped(?) tiny, long skinny bill, tiny feet, etc.
(Description:) Overall Pattern:	Iridescent purple head and throat, green back, pale eyebrow.
(Description:) Bill Type:	Long, skinny, nectar-feeding bill, slight droop at the end
(Description:) Field Marks and Identifying Characteristics:	Bright purple throat, appearing more vibrant and more magenta than BCHU. Purple gorget extending off and out to both sides, pale eyebrow behind eyes that goes down the cheeks; separating the gorget and top of head. Some purple on head, green feathers on back appear more of a blueish-green, especially compared to nearby BCHU. (see photos)
Song or call & method of delivery:	Silent for the most part, heard occasional brief calls, high-pitched chirping, almost more bubbly than a BCHU, and less sad sounding. Another call heard from it was sharper and higher-pitched than a BCHU call, not identical, but closer to a BTHU call but less ringy. From what I remember, sounds identical to calls on Merlin description.
Behavior:	Sipping from flowers on feeder. Hovering around, chasing off all other hummingbirds at the feeder. Landing occasionally on small twigs briefly, before taking off to chase away other hummingbirds again.
Habitat:	Arid shrubby desert within the canyons, few cottonwoods nearby, riparian corridor.
Similar species and how were they eliminated:	BCHU - Head not entirely dark, iridescent magenta as opposed to black. Pale eyebrow separating gorget from rest of head, no black chin. More of a bluish tint to back feathers. Higher-pitched chirping.
Previous experience with this & similar species:	None with COHU, but watched RTHU at home feeder every spring and summer. Experience observing western hummingbirds such as ANHU, RUHU, ALHU, & BTHU. In addition, I ve been to Costa Rica twice and been to their hummingbird gardens, with and without a professional birding tour guide as a part of Audubon s Costa Rica Teen Camp - identifying and picking out each individual species.
References consulted:	Liz Held
Description from:	Notes made later From photo(s) taken at the time of the sighting
Observer:	Cailyn Buchanan
Observer's address:
Observer's e-mail address:	**
Other observers who independently identified this bird:	Liz Held, Chris Zevellos, Hau Troung, Aidan B
Date prepared:	5/19/26
Additional material:	Photos
Additional comments:	Back of camera photos, can download digitally if needed.