Gulls Gulls Gulls

[Greg Neise]

Karen Mansfield, Tom Lally, Jeff Skrentny and I had a lot of fun working over the gulls at North Point Marina/State Line Beach today. There were thousands of mostly Herring gulls split between the harbor and the beach. Among them we found several THAYER'S GULLS, 4 LESSER BLACK-BACKED GULLS, 1 GREAT BLACK-BACKED GULL, 1 (Kumlien's-type) Gull, and because Tom Lally was with us, he pulled out an adult CALIFORNIA GULL.

Here's some pictures with some discussion


Adult Lesser Black-backed Gull


First cycle Great Black-backed Gull


First cycle Great Black-backed Gull among Herring Gulls, showing it's size, pattern and impressive bill

Now, this was an interesting bird...

The wingtips look too dark to be a Thayer's



...but the bird's head looks very much like a Thayer's Gull, with the dark eye and rather small greenish/yellow bill


Another shot of the same bird:

We left this as a "dark eyed" Herring Gull

Here's a third cycle Lesser Black-backed Gull:


...and here's a nice, distinctive first second cycle Thayer's Kumlien's Gull:




Here's an adult Thayer's Gull (in front) showing a nice comparison with a Herring Gull:








...and the same bird showing spread wingtips:


Here's a different, somewhat darker Thayer's Gull:






...and yet another Thayer's Gull, this one a bit paler. Getting it to do this synchronized preening routine with the Herring Gull was challenging:

[frakerpovc]

Superb photo thread, Greg -- except that it was the first thing I read after counting nearly 1500 Ring-billed Gulls for 6 hours -- seriously, I would have tied a strong one on if I had found a Herring Gull today.

If you have a Hell, Neise, it will be a place where you do what I did today, day after day after day....

Fraker

[Greg Neise]

Good stuff.  Thanks.

"..and here's a nice, distinctive first cycle Thayer's Gull:"
I'll bid up a cycle (2ND)

Yeah...I think you're right.

[Greg Neise]

Lastly, here's the "Kumlien's-type" bird:





It's wingtips were very pale...just a shade or so darker than the mantle.

[Robert D. Hughes]

Karen Mansfield, Tom Lally, Jeff Skrentny and I had a lot of fun working over the gulls at North Point Marina/State Line Beach today. There were thousands of mostly Herring gulls split between the harbor and the beach. Among them we found several THAYER'S GULLS, 4 LESSER BLACK-BACKED GULLS, 1 GREAT BLACK-BACKED GULL, 1 (Kumlien's-type) Gull, and because Tom Lally was with us, he pulled out an adult CALIFORNIA GULL.

Any photos of the California Gull?

Bob H

[Greg Neise]

Karen Mansfield, Tom Lally, Jeff Skrentny and I had a lot of fun working over the gulls at North Point Marina/State Line Beach today. There were thousands of mostly Herring gulls split between the harbor and the beach. Among them we found several THAYER'S GULLS, 4 LESSER BLACK-BACKED GULLS, 1 GREAT BLACK-BACKED GULL, 1 (Kumlien's-type) Gull, and because Tom Lally was with us, he pulled out an adult CALIFORNIA GULL.

Any photos of the California Gull?

Bob H

No, that was a frustrating moment. Tom found the bird mixed deep in the flock, with no real landmarks or anything to fix a location. We all took turns looking at it through his scope, and then went back to our own to attempt to find it ourselves...and get a picture or two. While this was going on, someone decided to take a walk on the beach and reshuffled the deck. We weren't able to locate it after that.

[Robert D. Hughes]

No, that was a frustrating moment. Tom found the bird mixed deep in the flock, with no real landmarks or anything to fix a location. We all took turns looking at it through his scope, and then went back to our own to attempt to find it ourselves...and get a picture or two. While this was going on, someone decided to take a walk on the beach and reshuffled the deck. We weren't able to locate it after that.

Bummer. I wish they all could be California Gulls. Nyuck, nyuck, nyuck. I was dying to say that...

Bob H

[Greg Neise]

No, that was a frustrating moment. Tom found the bird mixed deep in the flock, with no real landmarks or anything to fix a location. We all took turns looking at it through his scope, and then went back to our own to attempt to find it ourselves...and get a picture or two. While this was going on, someone decided to take a walk on the beach and reshuffled the deck. We weren't able to locate it after that.

Bummer. I wish they all could be California Gulls. Nyuck, nyuck, nyuck. I was dying to say that...

Bob H

ughh.   

[bill rudden]

These are really a great series of pics, with the juxtaposes with Herrings.

Note the gull marked Thayer's in Frames 19-22.
Caption states: ...and yet another Thayer's Gull, this one a bit paler. Getting it to do this synchronized preening routine with the Herring Gull was challenging:
The back shows as a bit more leaden (darker than Herring). Seems correct for Thayer's.  

Now go back to the gull marked Thayer's in Frames 11-15:
Caption states: Here's an adult Thayer's Gull (in front) showing a nice comparison with a Herring Gull:
Note the paler back than Herring. Seems more correct for Kumlien's here.


Thanks for posting.

 

[Greg Neise]

These are really a great series of pics, with the juxtaposes with Herrings.

Note the gull marked Thayer's in Frames 19-22.
Caption states: ...and yet another Thayer's Gull, this one a bit paler. Getting it to do this synchronized preening routine with the Herring Gull was challenging:
The back shows as a bit more leaden (darker than Herring). Seems correct for Thayer's.  

Now go back to the gull marked Thayer's in Frames 11-15:
Caption states: Here's an adult Thayer's Gull (in front) showing a nice comparison with a Herring Gull:
Note the paler back than Herring. Seems more correct for Kumlien's here.


Thanks for posting.

The lighting was low and changing (clouds scudding through)...we only saw one bird that I would have called "Kumlien's", and that bird was was fairly solid...being about J-K on the Howell and Mactavish scale (page 252 of Howell and Dunn, Gulls of the Americas)

[Amar Ayyash]

Bill, I think I follow what you're sayiing...the bird in frames 11-15 is paler than the Herring which could help eliminate Thayer's. Thayer's should be a shade darker than Herring and both birds are shot at the same angle. There are some Thayer's that can "appear" to have the same mantle color as Herring, but my understanding is that Thayer's should not be lighter.

Greg, look at the photograph above (35A.6) those primary plates in Howell (p.252). Even though we don't typically think of Kumlien's as having that dark primary pattern, some Icelands could resemble "q-r". Notice the black subterminal bar on P5 is not complete on both q and r.

Here is a quote from Olsen, "Note that younger adult kumlieni may show more dark on wing-tip, thus matching Thayer's. But any fully adult of these gulls [Thayer's or Kumlien's] with both black subterminal band on P10 and complete dark subterminal bar on P5 is Thayer's" (p.226).

I think frame 15 is the closest thing you have to an open wing...If I'm counting my primaries correctly, I'm sure P5 has no black on it. Kumlien's???

Good gulling,
Amar Ayyash

[Greg Neise]

We had a very similar discussion last year concerning this bird:



Of this bird, Micheal Retter said, "The white apical spots of the 2nd gull are huge in comparison to the Herring Gulls sitting behind it, and its dark primary markings are dark slaty, not black.  There are also white trailing edges to the inner webs on the near wing.  The bird's mantle seems lighter than the Herrings to me, but this could be lighting. Both the extensive white in the wing and the seemingly paler mantle speak to possible Iceland Gull parentage, and I'd suggest it could be what some call a "Kumlien's" X Thayer's intergrade.  In fact, there is a Kumlien's Gull shown in Howell & Dunn (35A.6 on p252) with a seemingly identical wingtip pattern, so perhaps it's just fine for a "pure" Kumlien's . . . whatever that is!"

Indeed, if I look closely at all of the "Thayer's" Gulls that I've photographed in the last 3 years, nearly half of them fit better with Kumlien's (as per Howell and Dunn).

In that thread, I posted pictures of these two birds I photographed at Fullerton Beach on 12/7/07 (that I called Thayer's Gulls):






...here's that last bird in flight, with P5 pointed out. Of this bird (both, actually...their wingtips were identical) Bill Rudden commented,
"The last pic would fit Kumlien's.
 RE:  P10 white tipped   
       P9 mirror crossing both webs
       P5 unmarked
       IMO. Respectfully."

And here's a closeup of yesterday's bird with the spread wing blown up, and P5 pointed out (showing the lack of a dark sub-terminal band):



I was a bit sloppy, I suppose for—as at least for the moment—these are two different species. So to recap, of the birds I photographed yesterday, I think 3 fit Kumlien's...including the 2nd cycle immature bird. With that bird, if we look again at Howell and Dunn, the relative lack of contrast between the mantle and the wingtips fits much better with Kumlien's (page 255, fig. 35A.20 and 35A.21) than 2nd cycle Thayer's (page 267, fig. 36.19, 36.21, 36.22).

Here they are again:








Then there's this bird, which has slaty, rather than black wingtips, but has a solid gray sub-terminal mark on P5:


Here we see the gray vs. black primaries, P10 mirror crossing both webs (arrow), but P9 mirror limited to the inside.


Here we see P5 with gray sub-terminal band (arrow).

The slaty tone of the primaries, plus the markings pointed out would seem to make this bird to be a Kumlien's X Thayer's intergrade.

[Amar Ayyash]

Greg, thanks for this great series of pics...so much to learn--so much fun! I'm convinced Tom Lally has a whistle that he uses to call in CA Gulls.
Tom, do let me know the next time you're going to Stateline Beach--I'd really like to see a CA Gull again.

All the best,
Amar



 

[Jeff Skrentny]

Tom Lally has a whistle that he uses to call in CA Gulls. Tom, do let me know the next time you're going to Stateline Beach--I'd really like to see a CA Gull again.

Amar, if that ain't the truth, I don't know what is! 

Tom, you need to be nice and go there with Al Stokie.  I am pretty sure he still would like to see a Cali Gull in Lake County.  He would love for you to use the whistle in his presence!

[troglodytes]

The Iceland, Kumlien's and Thayer's complex poses a real problem in that only Iceland is universally recognised as a true species.  Thayer's and Kumlien's are often considered as sub-species of Iceland.  This complex readily hybridizes within itself leading to birds that cannot be readily ascribed.  In addition F1 crosses also do hybridise within the complex .  See this from Wikipedia

There is continuing debate about the taxonomic status of this species, and some authorities consider Thayer's Gull to be the dark-mantled form of Iceland Gull, with Kumlien's Gull (variously treated as a subspecies of either Thayer's or Iceland Gulls) as an intermediate example, forming a cline rather than separate species. The American Ornithologists' Union considered Thayer's Gull a subspecies of American Herring Gull from 1917 until 1973, when they determined it was a separate species from Herring Gull. While numerous papers have since been written suggesting downgrading this species to a subspecies or even a morph of Iceland Gull, the AOU as well as all North American field guides continue to treat Thayer's Gull as a separate species. The British Ornithologists' Union follows the publication Birds of North America in lumping the three as forms of Iceland Gull.

The net  result is that we have birds that look like true Iceland, Thayer's and Kumlien's, but also many that fall somewhere in between.    It makes sorting through gull flocks challenging.