CA Gull or Herring Gull?

[simonthetanner]

Just had an interesting gull flyover on my walk this morning, and I need some help nailing down an ID. Odds are it's CA, but I'd like some confirmation from some gull gurus. I'm located in southern OR in Grants Pass, well inland from the coast and far from any large bodies of water. It was the briefest of flyovers, as it was just trying through and was probably driven over by the poor weather. We do not regularly have any gulls (except for a few RBGU in late March/April), so whatever this is it is an excellent bird for the county. 

It's a faded, younger bird, with plumage and head-shape generally matching a 1st winter CAGU; however, the beefy bill seems to fit HERG and my photos show a distinctly light eye on the bird. My impression in the field was that this was a rather large gull, and it was striking as it flew directly overhead and disappeared to the south.

Any suggestions?

[AlexHenry]

I think its Herring

[Nivalis]

I would go for California I see about 30 herring gulls every day and this bird would definitely have caught my attention if i had seen it, mainly because of smaller head size and because the bill is yellow while a juvenile herring gulls bill would be black.

[Connor Cochrane]

I would say 2nd Cycle Herring.

1. Shape seems good for Herring (seems to bulky for a California)

2. In the first photo, you can see a pale eye, which California Gull's don't have

Edited May 12, 2020 by Connor Cochrane

[Nivalis]

I guess I could see that but I still thing this bird is a cali

[Benjamin]

1 hour ago, Nivalis said:

I guess I could see that but I still thing this bird is a cali

It's more helpful to explain why, 

To me, this is a second cycle Herring Gull. The gray saddle and relatively light underside helps age this bird, as well as the dark outer primaries and light inner primaries. California Gull always shows a sharply bicolored bill, and I'm not really seeing one on this bird.

Also, it's worth noting that 2nd cycle Herring would not necessarily show a pale eye- the actual point at which the iris lightens seems to be pretty variable, and it's easy to find images of 2nd cycle birds with dark eyes. And fwiw, I don't think this bird actually has a pale eye- the images are very noisy, and in comparison to other dark areas of plumage (tail, wings) the eye looks significantly darker.

[rlp]

it seems to me the beak of a similarly coloured herring gull would be darker, and that the california might have black near the edge of the wings. are these the only two practical options? has Iceland been considered?

[Tony Leukering]

This is a weird bird. It's certainly a member of one of the four-year gull species, but it's plumage is not right for a first-year of any of them. The bird's outer primaries are pointed, identifying them as juvenile feathers. The wear of the flight feathers is consistent with a bird still in its first year of life. If that is true, then why does this bird have an adult color and pattern to its bill and have extensive adult-color plumage on upperparts and wing coverts? A second-cycle Herring in May should have replaced all of its juvenile flight feathers, which it obviously hasn't. Additionally, a 2nd-cycle that had retained all of its juvenile flight feathers would have horribly worn feathers, not feathers like these, which are in reasonable shape.

Thus, despite the plumage, I suspect that this is a first-cycle bird and Herring seems a much better fit for bill pattern -- there appears to be no black on the mandible proximally to the red -- than does Cal.