Verification of Unusual
Sight Record
For Utah
Rec. # 2025-04
| Common name: |
Black-headed Gull |
| Scientific name: | Chroicocephalus ridibundus |
| Date: | 1/25/2025 |
| Time: | 2:30pm~ |
| Length of time observed: | 30~ minutes |
| Number: | 1 |
| Age: | adult |
| Sex: | ? |
| Location: | Lee Kay Ponds |
| County: | Salt Lake |
| Latilong: | 40.7389386, -112.0495961 |
| Elevation: | 4250ft~ |
| Distance to bird: | 200m at closest |
| Optical equipment: | Kowa 66mm Spotting Scope |
| Weather: | overcast, snowing lightly, 31F, light winds |
| Light Conditions: | flat light but OK |
| Description: Size of bird: | small gull |
| (Description:) Basic Shape: | gull like |
| (Description:) Overall Pattern: | pale gray above, white below |
| (Description:) Bill Type: | Piscivor |
|
(Description:)
Field Marks and Identifying Characteristics: |
I was scanning through the mass of gulls on the ice when I noticed a
small gull keeping to it self on the edge of some open water. It was
much smaller than all the Ring-billed near it, had a similar pale mantle
shade, but a dark ear spot, so I immediately thought Bonaparte's Gull,
which have overwintered nearby on Great Salt Lake(Antelope Island
Causeway). But as I studied it in the scope, I noted its bill and legs
were a dark blood red. Bonaparte's have bright orange legs and a black
bill. I then carefully observed it and photographed it over the next
half hour in the scope, hoping for a view of the underwing to cling ID.
Eventually it did make a couple short flights, as well as flapped its
wings, and I did see the unique pattern of black and white on the
underside of the primaries that eliminated Bonaparte's and confirmed
Black-headed Gull. Specifically the inner primaries were mostly black,
but P8 & P9 were contrasting white with a black tip (see photos) |
| Song or call & method of delivery: | None heard |
| Behavior: | Loafing on ice near a small patch of open water |
| Habitat: | Freshwater ponds near a landfill and the south shore of Great Salt Lake |
| Similar
species and
how were they eliminated: |
Bonaparte's-overall very similar but smaller, have no black in underwing. Legs are typically a bright
orange-pinkish, not dark red, and bill of adults is normally black. Some
immature can have an orange based bill, but in adults, which this bird
was, it should be black. Franklin's Gull-much darker mantle shade, more prominent tertial crescent when perched, different black and white pattern in wingtips: lack white P8 & 9 and the white leading edge of upper wing. Bill and legs usually black in basic plumage Laughing Gull-larger and darker mantle shade, different black and white pattern in wingtips: lack white P8 & 9 and the white leading edge of upper wing. Bill and legs usually black in basic plumage Ring-billed Gull-direct comparison. about 50% larger, yellow bill and legs, different pattern of black and white in wingtips. No ear spot |
| Previous
experience with this & similar species: |
None, lifer. Many with Boneparte's, Franklin's, Laughing and Ring-billed |
| 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: | Several others independently relocated it after I left, see eBird |
| Date prepared: | 1/25/25 |
| Additional material: | |
| Additional comments: | eBird checklist: https://ebird.org/checklist/S210678243 |