24 November 2016

Putative Chandeleur Gull, California and Thiceland Gull

Michigan City, Indiana. 20 November 2016.

Chandeleur Gull

Sunday was my first genuine attempt at finding large gulls this season. Southern Lake Michigan's putative Kelp x Herring Gull (Chandeleur Gull) was holding to its regular post at Michigan City.

Always a late prebasic molt, p-molt is only about 1/2 way completed. The mirror on p10 is still relatively small (as it has been for years) with a squarish shape.

Mantle color tending toward Kelp, being a couple of shades paler than the primary tips. The head is blocky and the bill is hefty - similar to many Kelps.
I've now committed this bird's distinct voice to memory and this is how I was alerted to its presence. The long call doesn't sound like Herring Gull at all. Back in 2014 I also found this bird via its long call. After listening to multiple Kelp recordings, I've concluded that the voice is about as close of a match as one could expect for a bird that presumably has mixed genes.

The assumption here is that this individual associates with Herrings, and likely breeds (or attempts to breed) in Herring colonies. This also implies that it probably summers to our north (as opposed to our south), moving in with the first big waves of Herring Gulls that arrive on Lake Michigan in the Fall.

The underside to the flight feathers is dark gray (not black), and the legs are variably greenish-gray with very faint hints of pink, particularly around the webbing of the feet.

California Gull

Moving on, a continuing adult California Gull also brightened up the day. It's believed this bird has been in the area since late August.

The upperparts are darker than most CAGUs I've seen in these parts, but the bill is longer and "stronger" than average. I'm not sure how useful it is to try to assign these out-of-range birds to a specific subspecies. Interestingly, California Gulls banded as chicks in the Great Basin - presumably nominate californicus - have been recorded in the Lake Michigan region.

Thiceland Gull

No Lake Michigan day of gulling would be complete without a "tweener". At rest on the water the bird looked like it was going to be a Thayer's Gull:


Take a look at it in flight...

The wingtips looked paler than expected, and the markings were limited to the outer webs.

Fine, we'll call it a Kumlien's or whatever suits your fancy...