Sighting Record for Utah

Common name:	Yellow-billed Loon
Scientific name:	Gavia adamsii
Date:	11/15/2022
Time:	10:00am~
Length of time observed:	30~ minutes
Number:	1
Age:	juvenile
Sex:	?
Location:	Hyrum Reservoir
County:	Cache
Latilong:	41.624864, -111.870928
Elevation:	4,700~ft
Distance to bird:	150m at closest
Optical equipment:	Kowa 66mm Spotting Scope
Weather:	Sunny, clear, calm, cold 28F
Light Conditions:	Somewhat backlit but OK
Description: Size of bird:	Large loon
(Description:) Basic Shape:	streamlined
(Description:) Overall Pattern:	mostly pale buffy brown
(Description:) Bill Type:	Long-piscivorous
(Description:) Field Marks and Identifying Characteristics:	Bird_Description: "Juvenile on west side near dam buoys. Large loon(but no direct comparison with other loons), bulky square head with knob on forehead and chubby cheeked look, brown back with buffy barring, pale head with a buffy brown cast, no collar in neck, large pale ivory bill with yellow cast, curved lower mandible, upper mandible straight and pale. Bill held slightly pointing up while swimming." From my notes taken at time of sighting. (see photos)
Song or call & method of delivery:	Silent
Behavior:	Preening and sleeping on the reservoir near the dam, did some diving for a few minutes then resumed preening/sleeping
Habitat:	Freshwater reservoir
Similar species and how were they eliminated:	Common Loon-several present offering plumage comparison, but never right next to the YBLO. Overall darker with a charcoal gray head that always shows a partial collar in the neck, dark gray back, smaller bill that is silvery gray and all dark upper mandible often(but not always)held level. Smaller knob on the forehead. Some juvenile Common can be very pale, but always a smaller bill and colder gray tones. An addition feature that is not mentioned in books is YBLO have a swollen thick neck and chubby cheeked look, which was apparent on this loon. Apparently hybrids between YBLO and COLO have been documented, so some intermediate birds may occur, however this looked like a text book YBLO with no intermediate features. Pacific/Arctic Loons-smaller with a smaller gray straighter bill held level, rounded paler gray head, straight edged neck line. One Pacific Loon was present for comparison, notably smaller bill and silvery head. Red-throated Loon-smaller with very small gray bill held upright. Pale gray back with spots(not bars) either very whitish(adult basic) or uniform pale grayish(juvenile). Usually ride lower in water.
Previous experience with this & similar species:	Yes, my 5th. All juveniles in Utah
References consulted:	Memory
Description from:	Notes taken at the time of the sighting From photo(s) taken at the time of the sighting
Observer:	Bryant Olsen
Observer's address:	84102
Observer's e-mail address:	**
Other observers who independently identified this bird:	Stan Croft initial posted photos of a Loon that Merlin called a Yellow-billed on 11/14 here. I got the rare bird alert, photos looked good so I went to investigate. I hate to say it, but Merlin was right for once.
Date prepared:	11/16/2022
Additional material:	Photos
Additional comments:	eBird checklist: https://ebird.org/checklist/S122473711