Western Gull, the commonest gull on the west coast after California Gull. A large, short-winged and dark gull that is prone to huge amounts of variation and hybridization with Glaucous-winged Gull. There are two forms that occur on the coast, the darker wymani and the paler more American Herring Gull like occidentalis. These birds are more apparent in adult plumage as immature plumages are identical.
California - November 2009
Western and Yellow-footed Gulls
Heermann's Gull
Boneparte's Gulls
Mew Gull
Ring-billed Gull
California Gull
Thayer's Gull
Hybrids
Albino Gull sp.
Glaucous-winged Gull
Yellow-footed Gull
Western Gull
American Herring Gull
A typical dark, dingy looking first-winter Western Gull. Some of the lower scapulars are still juvenile. Obvious features are the large bill with large Gonydeal angle, the bulging prominently white tipped dark tertials and contrasting blackish primaries. This bird was photographed at the Salinas River Mouth. For more images of Western Gulls click here.
A second-winter Western Gull. Dark grey fresh scapulars are showing through whilst the head is mottled grey down to the breast and lower neck sides forming a hooded affect. The bill is bulbous tipped.
Third-winter Western Gull still showing the extensive grey mottling on the head and neck coming to a halt on the upper-breast creating the hooded affect. The bill on this bird is especially deep and bulbous.
The heavy head streaking could indicate a Glaucous-winged gull influence?
This full adult birds upper-parts are blackish with less contrast with the short black primaries indicating it is of the form occidentalis. Note the very broad white tertial crescent.
Compared with the occidentalis bird in the previous image the birds above and below which are paler above and have a slightly long primary project indicating that they are possibly wymanii. The bird above has a large tertial step and broad white tertial crescent, bulky appearance, white skirt as a result of the white trailing edge to the flight feathers, small dark eye and deep based, bulbous tipped bill are all suggestive of Western Gull however the upper-parts are a little pale for a pure Western Gull of the form occidentalis and the head streaking is also a little heavy thus the possibility of this bird being Western x Glaucous-winged Gull hybrid cannot be fully ruled out.
The Western Gull below does appear to have a more American Herring Gull stance with a fairly long looking primary projections and large white mirror to the underside of P10.
However the eye is dark, the upper-parts to dark and a bill shape and structure of Western Gull.
Along with Thayers Gull this species, the Yellow-footed Gull, was my other primary target species. As tis was a November trip the vast majority of Yellow-footed Gulls were back in Mexico but a few still spend the winter at the Salton Sea, which I was heavily reliant upon. I was lucky in getting this excellent adult at Obsidian Butte, albeit fairly distant thus resulting in a heavy crop.
Western Gull is rare at the Salton Sea however so is Lesser Black-backed Gull and there was one there whilst I was there thus providing a possible confusion; both being dark backed and yellow-legged. However Yellow-footed Gull has a huge, deep bill, relatively small looking head compared to body size, which is rather large and bulky and short primary projection. I'm pleased with the end result given the distance to the bird. For more pictures of Yellow-footed Gull click here.
Presumed occidentalis Western Gull due to slightly paler upper-parts, compare with the Western Gull in the slight foreground. There is a fair amount of streaking around the head though there doesn't appear to be any Glaucous-winged Gull features in this bird thus is probably within range of plumage variation of a pure Western.