American Herring Gull - Larus smithsonianus
Juvenile
American Herring Gull, juvenile: Roberts Lake Park, Monterey, California, USA - 26th November 2009
A dark individual. Aged as juvenile by virtue of the still juvenile scapulars; mid-dark brown with largish white tear droplets at the tips, colour matches that of the wing coverts and general plumage tone.
Interestingly for a bird with still juvenile plumage the bill has become pale based.
The head is rather contrastingly pale whitish with darker streaking, especially around the eye. Note the more solid outer greater coverts, the rather dark and solid tertials with neat notching and strongly barred under-tail coverts.
American Herring Gull, juvenile: Salinas River Mouth, Monterey, California, USA - 24th November 2009
A little more advanced than the previous bird in that a number of the scapulars are new 'barred' grey based feather; the anchor marked.
The head is also rather pale and the bill is strikingly pale pink based, early again for a juvenile.
The greater coverts are darker and more solid towards the outer wing whilst the tertials are dark brown with fine whitish notching at the tips and friners.
I think it would be difficult to pick such a bird out in a flock of European Herring Gulls as it doesn't fit the 'classic' appearance.
Same bird below.
American Herring Gull, juvenile: Bodega Bay, California, USA - 28th November 2009
A with the bird above another rather European Herring Gull type individual. Note the piano keyed patterned greater coverts and pale based bill.
Could such a bird be picked out in Europe?, doubt it. Are these birds within range of American Herring Gulls or are they hybrids, or even possibly from the west and are not American Herrings at all?
American Herring Gull, juvenile: Salinas River Mouth, Monterey, California, USA - 24th November 2009
A more unlike American Herring Gull that you could possibly find. Perhaps the slightly milky primary and tertial tone indicates a hybrid perhaps. The wing coverts are whitish and strongly pattered whilst again in Europe it would stand out from the crowd. With such difficulties in separating Eurpean Herring Gulls from Vega Gull could this bird be the latter, unlikely but outside chance.