The one day pelagic season

For a number of reasons yesterday was the first time this year we got out on the boat.  I'm guessing that it was the last day this year we got out on the boat.  The big loon flock that stages some years off Lakeside seemed to have moved on, we only saw the winter resident Red-throats.  We were able to chum in good numbers of gulls which would frequently move past inside of comfortable camera range.  There wasn't a ton of diversity of species, but there were a handful of Thayer's class birds over the day.

This juvenile stopped by briefly and landed quite backlit so I only had a handful of shots at it.

The prominent secondary bar and the longish bill probably elminates Iceland fairly easily.

Next is a 3rd winter bird.

A couple of flight views:

I think the tail is too dark to be an Iceland.  In adults Kumlien's Iceland is said not to have subterminal markings on P5 which this bird has.  About 90-95% of my 2nd and 3rd year Herring gulls shots have light eyes, Iceland usually has light eyes so the dark eyes are supportive of Thayers; I don't know how fast Iceland typically gets light eyes though.  P9 has dark along the entire leading edge which in adults is very good evidence for pure Thayer's.  The bill does have some pinkish tones which Olsen and Larsson note in Thayer's; Iceland at this age trends more towards greenish tones to the yellow.
I like this next shot mainly for the way the wings are catching the air; you can get a sense of the curvature that gives them lift.

Finally an adult bird...

Its eye is on the light end of the spectrum for Thayers (Howell and Dunn describe it as dirty yellowish to dark).  It's heavily hooded as in Thayer's.  The wing pattern with a tiny fleck on P5, and a very very narrow black leading edge to P9, and very little subterminal black on P10 is a little borderline.  Howell and Dunn show this pattern for Thayers-Kumlein intergrade in one of their (borrowed) plates, Olsen and Larsson would seem to put this wing pattern more solidly in the Thayer's camp based on their spreadwing plate.

Other pics I've posted ... adult Thayers Gull (also from boat last year), and a Thayer's type.

And coming soon to a blog near you, (drumroll please), a different dark-mantled hybird!!!