Sighting Record for Utah

Common name:	Western Gull
Scientific name:	Larus occidentalis
Date:	02/28/2014
Time:	3:40 pm
Length of time observed:	15-20 minutes
Number:	1
Age:	2nd Cycle
Sex:
Location:	Ogden Bay WMA
County:	Weber
Latilong:
Elevation:
Distance to bird:	55 yards
Optical equipment:	Vortex Viper HD Spotter, Pentax 10x50 Binos, Canon sx50 hs Camera
Weather:	Mostly Cloudy
Light Conditions:	Good
Description: Size of bird:	Very Large Gull, 28"
(Description:) Basic Shape:	Gull
(Description:) Overall Pattern:	Black, dark gray and white
(Description:) Bill Type:	Large, slightly bulbous tipped
(Description:) Field Marks and Identifying Characteristics:	Jet black, mirror-less primaries. Dark gray mantle with white head, breast and underparts. Pinkish legs. Large, slightly bulbous tipped bill that was yellow at the base and tip with black area about 2/3 of the way out. Head size/shape, eye size in comparison to head and iris color all matched what I've seen in WEGU on the coast. Overall size was large. Much larger than surrounding RBGU and CAGU, slightly larger than surrounding HEGU. In flight had dark underwing lining and tail. Top of tail was black with white tip, rump was white. (see photos)
Song or call & method of delivery:	N/A
Behavior:	Gull-like, stand in one spot for a couple of minutes and then would fly over to another. Bald Eagle in the area was keeping all the gulls on their 'toes'.
Habitat:	Shallow pond in marsh.
Similar species and how were they eliminated:	Pink legs, iris color, color of primaries and mantle, overall size eliminated most species of gull. For the closest in resemblance, the Slaty-backed was eliminated by bill size/shape/color and lack of whitish molting of scapulars (seen in most 2nd cycle birds). Great Black-backed would have had a different pattern to the tail, darker mantle, pinker legs and white coloring through secondaries.
Previous experience with this & similar species:	Have none with GBBG or SBGU. Experience with HEGU is quite extensive. WEGU, although I've seen a few in different cycles in Utah, is a bird I've seen quite often in the Santa Cruz area of the Pacific Coast.
References consulted:	Memory, Petersen's Reference Guide to compare notes taken at time of sighting and photos, Nat Geo Field Guide to the Birds of North America while in the field and opinions of other, more experienced birders (from Photo).
Description from:	Notes taken at the time of the sighting
Observer:	Mike Hearell
Observer's address:	173 W 1825 N, North Ogden, UT
Observer's e-mail address:	**
Other observers who independently identified this bird:	None at time of sighting. Solicited opinions of Kenny Frisch and Taylor Abbott later from photos taken.
Date prepared:	03/04/2014
Additional material:	Photos
Additional_Comments:	After seeing that WEGU was no longer flagged for rarity with last sighting in Salt Lake County I wasn't going to report to record committee. This is why there is a slight delay in my report.