first cycle Thayer's Gull

see proposed thayeri-kumlieni-glaucoides scale

October

Oct 10, 2000. Lake Winnipeg, Manitoba. Photo by Ann Cook.
From the underside, note the pale wings but also the thin dark trailing edge to the outer primaries, similar to a tern. Glaucous-winged Gulls do not show this.

November

Nov 1, 2013. Davis, California. Photo by Steve Hampton.
This is a very typical juvenile.

Nov 19, 2015. Petaluma, California. Photo by Steve Hampton.
Thayer's on right; Gl-W x Western on left. Note the latter has already molted its scapulars.

Nov 22, 2014. Davis, California. Photo by Steve Hampton.

Nov 22, 2014. Davis, California. Photo by Steve Hampton.
This one with more white in the scapular pattern; the other gulls are California.

Nov 30, 2010. Lake Mendocino, California. Photo by Matt Brady.
This is a fresh, dark, nicely marked, bird. While the brown parts are rather dark, the patterning is still fine for Thayer's Gull.

December

Dec 2, 1998. Southern California. Photo by Don DesJardin.
Note the touch of pale in the bill, which is uncommon but not extremely unusual. This bird is oiled above the left leg.

Dec 6, 2014. Davis, California. Photo by Steve Hampton.

Dec 9, 2014. San Francisco, California. Photo by Steve Hampton.
An example of one with messier greater coverts. Western Gull in the background.

Dec 10, 2014. Davis, California. Photo by Steve Hampton.
Thayer's on left; juvenile Herring (with holly-leaf patterned scapulars) on the right. Note bill size comparison.

December 10, 2001. Ventura, California. Photo by Don DesJardin.
Note the pale inner webs and darker outer webs of the flight feathers; also the extensive pale markings on the outer rectrices. The large pale terminal areas of the rectrices are a common characteristic, but is not shown by all birds.

Dec 14, 2013. Davis, California. Photo by Steve Hampton.
This one has exceptionally white greater coverts. The other gulls are California.

Dec 21, 1998. Southern California. Photo by Don DesJardin.

Dec 21, 1998. Southern California. Photo by Don DesJardin.
This one has exceptionally patterned tertials. Note the smooth brown head. Thayer's Gulls keep this nicely checkered juvenile plumage into February, later than most gulls.

Dec 28, 2014. Davis, California. Photo by Steve Hampton.
Two Thayer's Gulls; the lower bird has scapulars that approach the holly-leaf pattern of Herring Gull.

January

Jan 4, 2014. Davis, California. Photo by Steve Hampton.
Note the amount of pale in the scapular and covert pattern on this bird. All Herring Gulls in the background.

Jan 4, 2014. Davis, California. Photo by Steve Hampton.
Near-adult Herring Gull on the left; juvenile Thayer's on the right.

Jan 19, 2014. Davis, California. Photo by Steve Hampton.
This one has more patterned scapulars than most. Herring Gulls in the foreground.

Jan 24, 2014. Fort Baker, California. Photo by Steve Hampton.
This bird is beginning to fade. It is surrounded by California and Mew Gulls.

Jan 24, 2014. Fort Baker, California. Photo by Steve Hampton.
Another late winter bird beginning to fade.

Jan 24, 2014. Fort Baker, California. Photo by Steve Hampton.
Still a dark and crisp juvenile; Western and Gl-W Gulls in the background, with monstrous difference in bill size.

Jan 24, 2014. Fort Baker, California. Photo by Steve Hampton.

February
Feb 5, 2012. Davis, California. Photos by Steve Hampton.
This is a pale faded Thayer's with a hint of Kumlien's blood. The dark tertials and primaries rule out Iceland/Kumlien's, but the overall paleness and pale in the bill suggest some Kumlien's genes back down the line. At right, a more typical Thayer's is in the foreground. An apparent Herring Gull is in the background; note the larger bill.

Feb 7, 2014. Davis, California. Photo by Steve Hampton.

February 12, 2012. Sausalito, Calfornia. Photo by Steve Hampton. Unlike most other gulls, Thayer's retain their juvenile scapulars well into February. Birds along the coast, like this one, seem to be subject to more fading than inland birds during the course of the winter.

February 12, 2012. Sausalito, Calfornia. Photos by Steve Hampton. Finally, in mid-February we begin seeing Thayer's that have molted their juvenile scapulars, replacing them with some fresh feathers that show bits of adult gray.

This bird, undoubtedly a male, shows how strong a Thayer's bill can appear.

February 12, 2012. Sausalito, Calfornia. Photos by Steve Hampton. A typical faded juvenile in late winter.

February 12, 2012. Sausalito, Calfornia. Photo by Steve Hampton.This bird, on the pale side to begin with, has Kumlien's-like scapulars and patterned tertials, and an extensive pale ghost-bar on the tail. It likely has Iceland genes.

This photo shows Thayer's of all four cycles, including a variety of first cycle birds.

February 16, 2012. Petaluma, Calfornia. Photos by Steve Hampton. These are two different birds taken on the same day. Some birds have much more white in the upperpart checkering and look quite frosty from the back.

February 16, 2012. Petaluma, Calfornia. Photo by Steve Hampton. Here is a faded bird well into winter.

Feb 18, 2014. Morgan Hill, California. Photo by Steve Hampton.

Feb 21, 2014. Davis, California. Photo by Steve Hampton.
This bird is beginning to show some scapular molt; the other gulls are California.

March

March 1, 2012. Davis, Calfornia. Photo by Steve Hampton. This late season bird is showing extreme fading of the coverts.

March 23, 2011. Clearlake, Calfornia. Photo by Steve Hampton. This late season bird is showing some moulted scapulars with some adult gray in them, as well as some head and body molt. Otherwise, this bird is still in juvenile plumage, which is very typical. Note the much blacker primaries of the Herring Gull behind it (back right).

Take a look at these illustrations of first cycle wing patterns.