Confusing California Bird #1

[Dave]

Okay, here is the guy who really stood out of the crowd!














Well, you helped out my brother, now what are your thoughts on this one??

Dave

[Gord]

First impression was slaty-backed gull.

Yellow eye right?

Now I know the western gulls down south are a little different from northern ones, but Id say this guy doesnt fit due to heavy streaking on the head and bill shape which looks a bit thinner than it should be.


The things that hold me back from the slaty-backed idea:

It looks like there is dark on the bill above where the red should be? This bird looks like an adult winter plumage. (could always be mud or something!)

Looking at the ring-billed gull behind, this gull appears to be on the small side for slaty-backed. The size would work more for a lesser black-backed gull, but for starters, the legs are pink when they should be yellow.

I guess we always have to consider hybrid too. Lynn has good resources on gulls and possibly experience too with southern gulls and the possibilities to consider when birding there.

Other thoughts and other info to add to my comments Dave?

[Dave]

The Gull is definitely bigger than the Ring-billed Gull, so the picture might be decieving there.

Not sure on eye colour.

The legs were very pink, not light.

The challenge is that the sun is low on the horizon (late afternoon) so you have to take into account shadowing.

What really caught my eye was that the back was very, very dark. Distinctly darker than the normal Western, plus all the Western down there have cleanly white heads. This guy was very streaked. If I was in Chilliwack at the time, I would have been very confident this was a Slaty-backed from your pictures last year. Can you post them below again for comparison?

Dave

[Gord]

Darker than the westerns is good for slaty that's for sure. Pictures on the way.

[Gord]

[Dave]

white spots, no white spots

[Gord]

They are very small on your bird's wingtips arent they. I figured it was the lighting as you can see them if you look very closely.

[Gord]

Looking at the two, your bird looks a little more 'delicate' than the one we had up here. But then, a small female gull can look noticably smaller such as for example as in the herring gull, Thayer's gull ID challenge.

[henicorhina]

I was wondering about the dates and locations for both of these sets of photos. They both look like Slaty-backed Gulls, of which are only a few records in California.

[Gord]

I dont know the date for the California one, but the one we had in southwestern BC was January 22 of 2006.

I would imagine you guys wouldnt get too many slaty-backs down your way!

I think a slaty-back is a strong possibility. The only bird that fits to me.

[Dave]

I should add that the date the bird was seen was Saturday, Dec. 30. The location was right where Tijuana Slough meets the Ocean at the end of that rocky breakwater thing built there.

Dave

[henicorhina]

I would highly recomend that you submit these photos (and a description) to the California Bird Records Comittee. You can send them to the secretary at: [e-mail]
This would be a first county record, and the southernmost record in California.
I think it looks good for a Slaty-backed Gull. A number of marks that point to that species are the very dark back, streaked head, with streaks concentrated around the eye, broad white scapular and tertial cresents, a rather round head shape, a nearly straight-sided bill, and pink legs. However, there are some strange things about this bird, the main one being the apparent lack of bold white apical spots on the wingtips, but these could be worn off. It would help to know if this bird has a "string of pearls," is there a chance that you saw the bird in flight or got any flight or spread wing shots??? Adult gulls often retain some black on the bill, so that is not a problem. Glaucous-winged X Western Gulls sometimes show this head pattern, but they would have a paler back than a Western Gull, and would be structurally similar to one of those species, among other things.

Oscar Johnson

[Dave]

Thanks for your comments, Oscar.

I saw the bird fly-in, but was not looking at the particulars at that point. Once it landed (right in the middle of the terns I was looking at) I realized this gull was quite different from all the other Western Gulls I had seen in the previous days of birding the area, therefore lots of pictures! As a first-time to the area...I figured I could sort out the pictures once I got back home and had computer access. So no spread-wings or flight shots. Sorry

Dave

[henicorhina]

It would have been nice to have flight shots, oh well.
I would like to alert some local San Diego birders, as I'm sure they would all be very interested in looking for the bird. Also I'll forward the photos to the county NAB compiler (if that is alright with you). It would also be great if you could submit it the Bird Records Comittee.

Thanks,

Oscar

[Dave]

You can send the pictures where ever you think will be useful. Sorry about reporting this odd gull so late, but I had no access to the website. I did show the pictures to several people on the pelagic boat January 1 out of Mission Bay (I was on the boat), but most of them showed little interest and no one helped with the ID of this bird. The boat was overloaded with people, and perhaps I picked the wrong strangers to show the pictures to. (They were also on my small screen on the back of the camera). I will send the pictures to that email address, but since I am not very familiar with Western Gull variations (the only other option in my mind - other that LBBG with borrowed legs) I am not ready to stand behind any conclusion yet. Can I just send them the pictures with date/location and let them take it from there?

Dave