Verification of Unusual Sight Record
For Utah

Rec. # 2020-73

Common name:

Yellow-billed Loon

Scientific name: Gavia adamsii
Date: 11/17/2020  (confirmed on 11/22/2020)
Time: 7:30am
Length of time observed: 1 ˝ hours
Number: 1
Age: Juvenile
Sex: Unknown
Location: South Dike of Willard Bay (Accessed from Willard Playa)
County: Box Elder
Latilong: 41.355690, -112.132903
Elevation: N/A
Distance to bird: 500+ m (estimated.) Difficult to gauge distance accurately.
Optical equipment: Swarovski 20x60 Spotting Scope, Nikon Monarch Binoculars, Canon 7D w/ 100-400mm lens, and iPhone 6s+ for digiscoped images.
Weather: Intermittently cloudy, no precipitation. Slight to moderate wind. Cold temperature.
Light Conditions: Viewed for about 10 minutes before the sun rose over Willard Peak to our right. Heat wave ensued approx. 30 minutes after. Poor viewing conditions due to heat wave, indirect sunlight, and sheer distance from the bird.
Description:        Size of bird:  
(Description:)       Basic Shape:  
(Description:)  Overall Pattern:  
(Description:)            Bill Type:  
Field Marks and
Identifying Characteristics:
Notes from 11/17/2020: Observed a single loon towards the center of the reservoir while scoping directly north of our position from the south dike. First impressions were that it seemed off for a Common. Quinn and I spent the next hour+ watching the bird, gathering everything we could from the visible field marks at long distance. Following our time with the loon, we put together the following observations, all of which convinced us further of our ID as a Yellow-billed:

It appeared larger headed with an entirely pale, heavy-set bill. The bill was closely examined in various lighting scenarios and angles, and was consistently pale, lacking any presence of dark coloration on the upper mandible. Head and body appeared to be relatively dark, but not blackish like COLO at that distance, nor white/gray-toned as was visible in Red-throated and Pacific Loons seen at this location recently. There was no sharp delineation between the white throat and hood, which we described as an “undefined” neck border. It should be added that no triangular-shaped indent from the throat to the hind-neck was readily visible either. Even at a great distance, conspicuous pale-barring was visible on the back, while a confirmed, similarly distant Common Loon appeared uniformly dark-backed. Perhaps the most intriguing, and perhaps distinguishing feature able to be noted was the birds’ posture. It consistently held its’ head and bill upwards at an obvious angle, atypical of Common Loons to display for such extended periods of time. Unfortunately, the bird was never compared visually with any other Loon to effectively gauge size.


Despite the length of our observation and convincing summary of field marks, Quinn and I still withheld reservations and decided to leave the identification as tentative. Uncertainty remained due to distance, distortion, and inconclusive digiscoped images, however our views through the scope were quite convincing.

On September 22, 2020 Bryant Olsen, Lauri Taylor, and Vivian Schneggenburger found presumably the same individual, confirming the consensus that Quinn and I shared regarding the loon observed on the 17th. It was initially spotted with two Common Loons within 100 meters of the south dike while Quinn and I were scoping the bay from the northwest corner. We arrived shortly after getting word and were delighted to find it in direct comparison with a Common Loon within binocular range. Many photos were taken by multiple observers at this time (DSLRs, point-and-shoots, and digiscoped images).

Many of the same field marks noted on the 17th applied to this bird as well. The so called “undefined” neck border, conspicuous pale-barring across back, large-headed appearance with a peaked forehead, large and entirely pale bill, head and bill held at an upwards angle consistently, and pale-brownish head and body (although appearing darker at a distance on 11/17). The head shape was more readily observable, showing a flatter crown than common with a strong peak at the forehead. Additionally, side-by-side comparisons were obtained with a Common Loon, which properly displayed the dramatic size difference between the two species (YBLO being considerably larger). The sighting today (11/22) comes five days after the initial sighting by Quinn and I, confirming our inconclusive report and validating the field marks which we both observed and recorded in the field.

Attached will be two pics attached from 11/17 showing the best of our inconclusive photos and perhaps more accurately portraying the distance it was from us. Both were digiscoped through spotting scope at 60X. All other photos will be added from our observations of the Loon on 11/22.
(see photos)
Song or call & method of delivery: Silent
Behavior: Sat on the water casually, preening and resting from time to time. Diving occasionally.
Habitat: Center of Willard Bay – Deep, fresh-water reservoir.
Similar species and how
were they eliminated:
Common Loon: Conspicuous pale barring across back; Entirely pale-yellow bill lacking dark-coloration on upper mandible; Much larger with bulkier head, flatter crown and peaked forehead; head and bill consistently held at upwards angle, atypical of COLO. Much paler brown overall, especially on the face and neck without a well-defined neck border. No conspicuous inverted triangle on lower neck.
Previous experience with
this & similar species:
I have encountered a juvenile Yellow-bill Loon once before, but have studied them extensively. Extensive experience with Common and Pacific Loons and limited experience with non-breeding Red-throated Loons.
References consulted: Sibley Guide to Birds, Macaulay Library,
Description from: Record compiled from an accumulation of notes made during and after the sighting. Some details added from memory.
Observer: Kendall Watkins, Quinn Diaz
Observer's address: 2622 W Dry Creek Drive, Riverton,: Utah  84065
Observer's e-mail address: **
Other observers who independently identified this bird: Quinn Diaz, James Loveless, Mike Hearell, Taylor Abbot, Bryant Olsen, Vivian Schneggenburger, Lauri Taylor, Mike Malmquist, Max Malquist, Ryan Painer and others.
Date prepared: November 22, 2020
Additional material: Photos
Additional comments: