Verification of Unusual Sight Record
For Utah

Rec. # 2016-31

Common name:

Western Gull

Scientific name: Larus occidentalis
Date: 09-13-2016
Time: 5:00pm
Length of time observed: 15 minutes
Number: 1
Age: Juvenile
Sex: ?
Location: Lee Kay Ponds
County: Salt Lake
Elevation: 4250 ft
Distance to bird: 50m
Optical equipment: Bushnell 20-48X spotting scope
Weather: Overcast, 70F
Light Conditions: Good
Description:        Size of bird: Large gull, 25in
(Description:)       Basic Shape: Typical Larus Gull
(Description:)  Overall Pattern: Very dark sooty brown
(Description:)            Bill Type: Fairly large, all black
Field Marks and
Identifying Characteristics:
What 1st caught my eye was the dark brown sooty color, also notably larger than California Gulls. Had a large black bill with notable gondynale angle, also had a relatively short primary projection past tail, and notable "secondary skirt", as well as a large round head with eye in the center, all this adds up to a juvenile Western Gull.
(see photos)
Song or call & method of delivery: None heard
Behavior: Swimming in pond, then loafing on an island
Habitat: Freshwater ponds near a landfill, not far from the Great Salt Lake
Similar species and how
were they eliminated:
California Gull: Smaller, with a smaller bill that usually has a pink base at this age, even the darkest juvenile California's are a shade lighter brown with more white checkering in the wing coverts, mantle and nape. Longer wings with longer primary projection and different overall structure. Direct comparison.

Herring Gull: Can be similar, but usually paler, often has a pink bill base, different structure with longer primary projection, lacking "skirt", and with a flatter head with more forward eyes. Bill usually smaller but there is overlap.

Yellow-footed Gull: always paler and bigger

Glaucous-wing Gull- always paler, has pale primaries.

Olympic Gull(Western X Glaucous-winged): Usually paler, and primaries not black, should be similar in shade to mantle.

Heerman's Gull: Immatures can also be uniformly very dark, but are much smaller and petite, smaller than California Gulls
Previous experience with
this & similar species:
Yes, many: adults, immatures and juveniles, also with all of the gulls listed above except Yellow-footed.
References consulted: Sibley, online photos, memory
Description from: From photo(s) taken at the time of the sighting
Observer: Bryant Olsen
Observer's address: 688 East 700 South #105, SLC, UT 84102
Observer's e-mail address: **
Other observers who independently identified this bird: none
Date prepared: 09-13-2016
Additional material: Photos
Additional comments: Initially seen on 9-9-16, but my view on that day was less than satisfactory, so not positive of ID, however this caused me to do more study on juvenile Western Gulls, when I relocated it on this day, all doubt was eliminated. As far as I can tell, this is the earliest fall record in Utah, by a couple months.