Date: 3/10/26 11:17 am From: Jane Hadley via Tweeters <tweeters...> Subject: [Tweeters] Follow up on the call for ID help on a gull
Hello Tweetsters - Thank you to those who responded to my request for help
identifying a gull my husband and I saw at Cedar River Mouth March 1st.
Twenty-seven people weighed in. I think it's safe to say that we do not
have a consensus on the identification. That's not surprising given the
continuing debate about subspecies vs. hybrids and the difficulties
identifying the subspecies. Birds of the World says "Subspecies ... are
not always separable."
I had other pictures of the bird standing next to other species, which
might have been helpful in identifying it. I should have included those
pictures. Here is a link to them now:
Three subspecies of Iceland Gull are generally recognized today: 1) the
nominate or Iceland subspecies of the Iceland Gull; 2) Kumlien's; 3)
Thayer's.
The three subspecies mainly differ in the darkness and patterning of the
wingtips in adults and older immatures. Iceland subspecies has very pale,
often pure or nearly pure white wingtips. The Kumlien's wingtip tone is
intermediate gray. The Thayer's wingtips darkest of the three: dark gray to
almost black.
There are also geographical differences, with Thayer's the most common in
our area, Iceland rare, and Kumlien's in between. If you look under
"Systematics" and then "Geographic Variation" of the Iceland Gull at Birds
of the World, there is a discussion and links to eBird range maps for each
of the subspecies.
I think I made a mistake in relegating the Iceland subspecies to the
"Other" category rather than listing it as a third option, even though it
is mostly found in Greenland, Iceland and Europe. Within the "Other"
category, I am assuming that when people said "Iceland," they were
referring to the subspecies rather than the species name, unless they said
otherwise. Under that interpretation, there were 4 votes for the Iceland
subspecies (6 if you count "Leucistic Iceland"). So in presenting the
results, I'm counting Iceland subspecies as a third option.
Total votes: 27
Leucistic Thayer's 8 or 30%
Kumlien's 8 or 30% [Includes one vote by email]
Iceland subspecies 4 or 15%
Other 7 or 26%
The 7 Other IDs:
1. Leucistic Iceland - 2 votes
2. Immature Glaucous - 2 votes
3. Thayer's 2nd or third year - 1 vote
4. American Herring Gull - 2nd year - 1 vote
5. Ring-billed - 1 vote
I submitted three pictures to Merlin, which identified all of them as
Iceland Gull. Merlin does not do subspecies. But Merlin does not think it's
a Glaucous, Herring or Ring-billed.
Below are the comments submitted along with the votes. I have removed the
names associated with the comments since I didn't ask permission to publish
the names on the Internet. (Probably another mistake on my part.)
===== Submission: 2026-03-09 15:00:28 =====
Vote: Kumlien's Gull
Explanation: While hard to eliminate a worn Thayer’s Gull, I see no reason
why this isn’t a Kumlien’s.
===== Submission: 2026-03-09 15:18:14 =====
Vote: Other
Explanation: It’s hard to say for sure but I’m fairly certain it’s not a
Kumlien’s type. I think this coloration is safe to rule that out. It
appears to be a leucistic Iceland sized gull though
===== Submission: 2026-03-09 15:18:46 =====
Vote: Other
Explanation: The bill is characteristic of a late second cycle or even
early 3rd cycle L.g. thayeri. The irides has not attained adult
coloration.Pink legs. Heavily bleached out indicating some retention of
previous cycle feathering, Next molt will be either full adult or
sub-adult. Not kumlieni.
===== Submission: 2026-03-09 15:20:03 =====
Vote: Other
Explanation: Iceland Gull
===== Submission: 2026-03-09 15:53:21 =====
Vote: Other
Explanation: Was it too big to be an immature Glaucous Gull?
===== Submission: 2026-03-09 15:56:18 =====
Vote: Kumlien's Gull
Explanation: Definitely some kind of Iceland Gull. Maybe Kumlien's. Mind
you, I am not a gull expert!
===== Submission: 2026-03-09 16:00:44 =====
Vote: Kumlien's Gull
Explanation: Looks very much like a subadult Iceland Gull to me. Tiny bill,
long wings, not to mention that all coloration elements look good for that
species. And it was good to see it in comparison with both larger and
smaller species.
===== Submission: 2026-03-09 16:01:33 =====
Vote: Other
Explanation: This gull looks a lot like the third cycle Iceland nominate in
Amar Ayash's The Gull Guide (Princeton University Press 2024). See page
422, photograph 21. That bird is a third cycle gull. Your gull shows the
bill of a second cycle nominate in photo 16 on the same page. The puzzle
that are many gulls can be frustrating but also such fun. Please post your
further thoughts, as well as a summary of viewer comments to Tweeters.
Thanks!
===== Submission: 2026-03-09 16:05:41 =====
Vote: Other
Explanation: Iceland Gull
===== Submission: 2026-03-09 16:05:43 =====
Vote: Leucistic Thayer's Gull
Explanation: Bill looks good for Iceland Gull (Thayer's). I don't believe
there are any gulls that are pure white without any markings. Love your
poll.
===== Submission: 2026-03-09 16:08:25 =====
Vote: Leucistic Thayer's Gull
Explanation: I'm not sure there is a right answer but it appears to have
molted some juvenile scaps so I'm thinking it is second cycle and the scaps
are a little darker than what might be found in some pale (per the Gull
Guide by Amar Ayyash) variants of Kumliens. So Leucistic Thayer's seems
right but a Kumliens might also have some leucism.
===== Submission: 2026-03-09 16:36:49 =====
Vote: Kumlien's Gull
Explanation: Bill slightly smaller than Thayer's. Rounder, slgithly smaller
head profile. Light iris. Looks a bit like some photos of second winter
Kumliens. But I'm no expert. there's a nice Gull ID page on FB that would
I'm sure give you some good feedback.
===== Submission: 2026-03-09 17:48:08 =====
Vote: Leucistic Thayer's Gull
Explanation: I have seen this bird at the Yellow Freight Building in
Tukwila! It doesn’t scream Kumlien’s to me due to the pure white and lack
of any light brown patterning that would be typical of immature Kumlien’s.
Apparently this is a bird that has been seen and documented returning to
the area over the past few years.
===== Submission: 2026-03-09 20:07:29 =====
Vote: Other
Explanation: American herring gull, 2nd year. The pink in the bill rules
out Icelandic gull, eliminating your other choices. herring gulls can be
nearly all white as second year gull but will have the dark wing tips,
which you can just see in this photo.
===== Submission: 2026-03-09 20:23:04 =====
Vote: Other
Explanation: It’s hard to say for sure but I’m fairly certain it’s not a
Kumlien’s type. I think this coloration is safe to rule that out. It
appears to be a leucistic Iceland sized gull though
===== Submission: 2026-03-09 20:58:08 =====
Vote: Leucistic Thayer's Gull
Explanation: I have seen this bird at the Yellow Freight Building in
Tukwila! It doesn’t scream Kumlien’s to me due to the pure white and lack
of any light brown patterning that would be typical of immature Kumlien’s.
Apparently this is a bird that has been seen and documented returning to
the area over the past few years.
===== Submission: 2026-03-09 22:16:28 =====
Vote: Other
Explanation: Iceland Gull, not sure what subspecies. If I were at home, I'd
get out my big gull book...but I'm in Hawaii!
===== Submission: 2026-03-09 22:41:48 =====
Vote: Other
Explanation: My first guess would be ring billed bill with a pigment issue
--but that's almost entirely a guess.
