 Roberts Lake Monterey (4).JPG)
 Roberts Lake Monterey (4).JPG)
 Roberts Lake Monterey (5).JPG)
 Roberts Lake Monterey (5).JPG)
 Roberts Lake Monterey (4).JPG)
 Roberts Lake Monterey (4).JPG)
 Roberts Lake Monterey (4).JPG)
 Roberts Lake Monterey (4).JPG)
Glaucous-winged Gull, 4th-winter: Roberts Lake Park, Monterey, California, USA - 11th March 2007
The two images above relate to the same individual. Compared with the 3rd-winter the primary spots are larger and the bill is predominantly pale off-yellow in colour with subterminal band. There is still a hint of brownish tones in the upper-parts, tertials.
Here also there is greyish lower hind neck and neck side mottling left over from winter plumage. Again note the short primary projection. The primaries themselves are grey, though only a little darker than the upper-parts.
Glaucous-winged Gull, 4th-winter: Roberts Lake Park, Monterey, California, USA - 11th March 2007
A cleaner, tidier looking bird with less obvious wear to the flight feathers. There is less head and neck streaking giving a whiter head and neck. The primaries are mid grey and are short. The white tips are small and inconspicous. The white tertial crescent is large and obvious.
Glaucous-winged Gull, 4th-winter: Roberts Lake Park, Monterey, California, USA - 11th March 2007
Same bird as above though showing wing pattern. On the upper wing note the large mirror on P10 and the small mirror on the outer web of P9. P10 lacks an obvious white tip as shown by P9-P7 though it does have a tiny white spot on the tip of the outer web. The primaries are a duller, dirtier looking grey than that on the wing coverts with the distal portions of the visible primaries even duskier.
On the underwing the primary patter is less obvious though the large mirror to P10 and the white tips to P9-P7 are still visible. As can be seen the underwing is pale grey which could cause misidentification at range.
Here also the upper-tail is just visible with the central feathers looking mid grey.
Glaucous-winged Gull, 4th-winter: Roberts Lake Park, Monterey, California, USA - 11th March 2007
Same bird above and below: Note the fine greyish barring from the head down to the breast which contrasts with the clean mid grey upper-parts and white under-parts. The primaries on this bird are heavily worn but can still be seen to be a few shades darker than the upper-parts. Note also the broad wing trailing edge to th secondaries.
Glaucous-winged Gull, 4th-winter: Roberts Lake Park, Monterey, California, USA - 11th March 2007
The above and below images show the respective upper and under-wing patterning.
Glaucous-winged Gull - Larus glaycescens
Fourth-years
Glaucous-winged Gull, 4th-winter: Salinas River Mouth, Monterey, California, USA - 26th November 2009
A typical fourth-winter bird; note the grey primaries which match in colour and tone the rest of the upper-parts and the fine but dense barring in the head, neck and upper-breast.
The legs are rather short and bubblegum pink and the ye is quite large, dark and central in the face. The bird is aged as a fourth-winter by virtue of the still immature bill patterning.
Jizz wise the bird is large bodied with a somehow disproportionately small, squarish looking head.
Same bird below amongst Western and California Gulls.
Glaucous-winged Gull, 4th-winter: Salinas River Mouth, Monterey, California, USA - 26th November 2009
Note the grey primaries are a little darker than the upper-parts which could indicate some hybrid influence, especially note P5 matches the closer to the upper-parts.
The white primary tips are rather small due to the bird not being adult whilst other fourth-years attributes are the the pinkish bill base and dark bill markings and the dark mark in the outer rectrices.
Other good Glaucous-winged Gull features are the upper-part tone, rather pale, bright pink legs, steep tertial step, dark eye and the fine head, neck and upper breast barring.
Glaucous-winged Gull, 4th-winter: Point Pinos, Monterey, California, USA - 25th November 2009
Aged as a fourth-year bird due to the still extensive dark bill markings and the darker grey markings in the tail whilst the white primary tips are small.
The most interesting features in this image are the noticeably broad white trailing edge and the slightly darker tips to the outer primaries. There is a largish mirror on P10 and a dark band across P5.
Most interesting though are the white moons on P6-P8 which create a half line of a 'string of pearls' across the spread wing. P9 is completely unmarkedr