Verification of Unusual
Sight Record
For Utah
Rec. # 2024-92
| Common name: |
Yellow-billed Loon |
| Scientific name: | Gavia adamsii |
| Date: | 12-20-2024 |
| Time: | 2:45pm~ |
| Length of time observed: | 30 minutes |
| Number: | 1 |
| Age: | immature |
| Sex: | ? |
| Location: | Rockport Reservoir |
| County: | Summit |
| Latilong: | 40.769102, -111.397934 |
| Elevation: | 6,000ft~ |
| Distance to bird: | 200m at closest |
| Optical equipment: | Kowa 66mm Spotting Scope |
| Weather: | Sunny, clear, calm, 55F |
| Light Conditions: | Excellent |
| Description: Size of bird: | large loon |
| (Description:) Basic Shape: | streamlined diver |
| (Description:) Overall Pattern: | buffy brown overall |
| (Description:) Bill Type: | Piscivor |
|
(Description:)
Field Marks and Identifying Characteristics: |
Large loon, notably bigger than the Common Loon it was associating with,
bulky square head with knob on forehead and chubby cheeked look, brown
back with buffy barring, pale head with a buffy brown cast, faint hint
of a collar in neck, large pale ivory bill with yellow cast, curved
lower mandible, upper mandible straight and pale. Bill often held
slightly pointing up while swimming. Bill was noticeably longer, thicker
and paler than the Common Loons bill. (see photos) |
| Song or call & method of delivery: | None heard |
| Behavior: | Swimming on the water, often diving |
| Habitat: | Freshwater reservoir. |
| Similar
species and
how were they eliminated: |
Common Loon-one present offering direct comparison. Overall darker with
a charcoal gray head that always showed a prominent partial collar in
the neck, darker gray back, smaller bill that was silvery gray and all
dark upper mandible often(but not
always)held level. Smaller knob on the forehead, and smaller overall by
about 25%. This juvenile Common was very pale, but always had 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. Pacific/Arctic Loons-smaller with a smaller gray straighter bill held level, rounded paler gray head, straight edged neck line. 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 6th. All juveniles in Utah |
| References consulted: | Sibley app |
| Description from: | 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: | Initially found on 12/19 by Dave Handscom, seen by many over then next few days |
| Date prepared: | 12/28/24 |
| Additional material: | |
| Additional comments: | eBird checklist: https://ebird.org/checklist/S206031911 |