Glaucous-winged Gulls, and their associated hybrids, are abundant in the bay area during the winter months. The most straightforward ones to ID look something like this; dark eye, pale bill, dark/barred (as opposed to streaked) hood, and pleasantly pale primaries. All photos from this post were taken at Oyster Bay Regional Shoreline, San Leandro, CA.
Here in the bay area, November is typically the month where birders begin looking at gulls again. I never look forward to this. By this time, I typically have not been obsessively looking at gulls since March, and my Larid skills have gotten a bit rusty. Luckily, November is generally not a great month for vagrant gulls (although Slaty-backed has shown up this early), so it's good to get my inner Gull Machine (a large part of my brain that is devoted to doing nothing but process gull identifications) firing on all cylinders again.
I hate gulls, but I just can't help myself. I must look at them. They demand my attention. I want the glory, the fame, and the sex of finding the state's second Great Black-backed Gull, or another precious Black-tailed Gull. I want to be able to competently discuss such obscure identification features that if I try to describe them to another birder, their eyes will just glaze over in utter horror and confusion...and you know what? I'm well on my way there, but unfortunately many birders are still able to understand what I am talking about, gulls are still frustrating to identify, and birding is still hard...and that is why I fail.
Thayer's Gulls are back; this is the first adult I've seen this year. Note how tiny it is compared to the big hybrid gull in the background. Speaking of the hybrid (note the almost-but-not-quite black primaries), it's clearly part Glaucous-winged, but I'm not sure who the other parent is. It's shaped like a classic Glaucous-winged X Western but the way the mottling/streaking (strottling?) looks on the head makes me wonder if Herring genes are in there. I don't know, you tell me...isn't birding hard?
Check out the massive white apical spots on this bird. Lookin' sharp.
My, what an appealing wing pattern you have Thayer's Gull. This is a pale-eyed Thayer's Gull, which are not uncommon locally.
The adult gulls here are still molting in their new primaries; check out p10 coming in on the leading edge of the wing, and how far it has to go before it's fully grown in. Wonderfully vivid feet on this bird, which is to be expected.
For more on Thayer's Gull ID, or if seeing a bunch of Thayer's Gull pictures is what gets you going, be sure to check out my sprawling Thayer's Gull post from earlier this year.
Shortly after the adult Thayer's Gull flew off, I spied this bird bathing in the same area. It looked rather similar...pale eye, heavily-marked head (not streaky like a Herring), relatively small...another Thayer's?
Hmm...there's no mirror on p9, which is highly indicative of Herring Gulls in the western U.S. And the mottled head is starting to look crosshatched, a very Glaucous-winged trait.
And now the bird seems pretty pale on the underwings...not dissimilar to a Thayer's. So if a gull has a wing pattern that looks like a Thayer's from below but a Herring Gull from above, what is it?
If you guessed that this bird was a Glaucous-winged X Herring Gull hybrid, I would wager that you are correct. If you ask me, this hybrid combination resembles Thayer's Gull more than any other. Fortunately, the "Cook Inlet Gull" is common here during the winter and provide ample opportunities for study. Unfortunately, the "Cook Inlet Gull" is common here during the winter months and I am forced to waste countless hours looking at them trying to figure out what the hell they are.
I only got to look at this bird very briefly in flight, and even more briefly on the water. At first glance I assumed this would be a 2nd-cycle Glaucous-winged X Herring Gull, but with my short look at the bird on the water and looking at these photos now, it appears to be Glaucous X Herring. Nelson's Gulls can be challenging to track down around here (for me, anyway), so this turned out to be a pretty nice bird.
Though a bit dark, I think if you took off this bird's head and attached it to a Glaucous Gull torso, it would look right at home.
Luckily, Bonaparte's Gulls are attractive and don't want to grind cloacas with all their closest relatives. And for that, Bonaparte's Gulls, I thank you.