First Thayer's of the Fall and More LBBGs - 2012

I went up to the Lake County Fairgrounds in northeastern Illinois this morning. There was a good presence of Thayer's Gulls (5) and Lesser Black-backeds (8). Best of all, birding was from the car which made the 30 mph winds a bit more tolerable.

Adult Thayers with adult LBBG. Lake County, IL. 23 November 2012.

 

First cycle LBBG. Lake County, IL. 23 November 2012.

2nd Cycle LBBG. Lake County, IL. 23 November 2012.

4th Cycle LBBG. Lake County, IL. 23 November 2012.

Adult LBBG.  Lake County, IL. 23 November 2012.

Adult Thayer's Gull (front) with American Herring Gulls. Lake County, IL. 23 November 2012.

Adult Thayer's Gull with Herrings in background. Lake County, IL. 23 November 2012.

Adult Thayer's Gull. Lake County, IL. 23 November 2012.

Adult Thayer's Gull. Lake County, IL. 23 November 2012

 

 

 

Both the Thayer's and the LBBGs were still undergoing outer primary and variable secondary molt:

 

Adult Thayer's. Lake County, IL. 23 November 2012.

 

Adult type LBBG. Lake County, Il. 23 November 2012.
 

Still waiting on this season's first Iceland and Glaucous Gull!

Can You Say "Astaxanthin"

Astaxanthin is the carotenoid thought to be responsible for the pink feathers we see in gulls (McGraw, Hardy 2005). I've written on this subject in a previous post, but I'm now wondering if this same carotenoid is responsible for the extra yellow/orange we see in bare parts.


Adult Ring-billed Gull. 25 March 2012. Chicago, IL.
Note the pink blemish on the face, neck and breast.

Not only does this individual display pink in its plumage, but the bare parts are on hyper-orange!

Compare it to these ordinary March RBGUs:

It's curious to say the least...

Indiana Bonaparte's Gulls

Today was a relatively good day for BOGUs on the Indiana lakefront. I observed scattered flocks in Michigan City and at Miller Beach, but the real reward came in Whiting at the BP refinery where I found 71 individuals feeding at the discharge.

Adult BOGU. Michigan City, IN. 11 November 2012.

First Cycle BOGU. Michigan City, IN. 11 November 2012.

First Cycle BOGU. Whiting, IN. 11 November 2012.

Adult BOGU. Whiting, IN. 11 November 2012.

2nd Cycle BOGU. Note the faint black marks on the subterminal part of the tail.

Same individual as above. The black tips to the greater primary coverts and black
markings on the outer web of P9 point away from an adult.

Sadly, Bonaparte's declined greatly on lower Lake Michigan after the 1990s. Of the four states surrounding Lake Michigan (Wisconsin, Illinois, Indiana and Michigan) it seems Illinois sees the least of this species.