Posted by Nick Lethaby (209.140.231.138) on August 08, 2000 at 10:09:10:
The swallow looks like a female/imm Violet-green. My impression is that females have a much less well marked head pattern than males.
Although one photo is rarely enough to attempt id of a difficult gull, I would be surprised if the gull is not a GW Gull. It's almost certainly photographed in the SF Bay area where adult Glaucous Gulls are pretty rare. I feel the all white head and small beady eye are strong pointers to GW Gull. I also agree with Steve Hampton's comments on the mantle color. Wing tip coloration is quite variable in GW Gull. For example, birds in Japan have much darker wing-tips than many of the birds wintering in California. ALthough, these wing-tips are definitely on the pale side for an adult GW Gull I think they are probably OK - I find you usually need to see the bird in flight to accurately check the wing tip tone. I agree the primary extension is on the long side for GW Gull, but I am sceptical about the value of this feature for diagnostically identifying individual birds, since I see a lot of variation in this due to wear etc.