Verification of Unusual
Rec. # 2016-31
|Scientific name:||Larus occidentalis|
|Length of time observed:||15 minutes|
|Location:||Lee Kay Ponds|
|Distance to bird:||50m|
|Optical equipment:||Bushnell 20-48X spotting scope|
|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
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.
|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|
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
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's address:||688 East 700 South #105, SLC, UT 84102|
|Observer's e-mail address:||**|
|Other observers who independently identified this bird:||none|
|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.|