Monday, November 9, 2009

Weird gulls galore

Tim and I worked our way down the shoreline this morning, not finding a whole lot, until we hit a decent gull flock at New Buffalo. This Franklin's Gull isn't weird, but was a fun bird, probably my best photos of the species. Note how much bigger the white primary spots are and how much fuller the half hood is than what an adult Laughing gull would show. The bill is also shorter and more slender than a Laughing gull's. A hint of the breeding red color to the bill is retained at the bill tip.

Next is a pretty funky looking Herring Gull.
The eye is darker than the average Herring's (though in the field was more of a dark amber than truly dark), and the head is enormous with the heavy-jawed glaucous look to it. The orbital ring was a pale red. Herring gull's orbital ring is described as orange-yellow by both Sibley and Olsen and Larsson, and yellow-orange by Howell and Dunn. We wondered if the bird could have some Glaucous-winged genes somewhere in its history. I couldn't find any reference as to what percentage of adult Herring gulls have dark eyes, though experience would say the number is clearly not zero. We didn't get a view of the spreadwing as the flock was dissipated abruptly when a young Parasitic Jaeger flashed into view.

This Lesser Black-backed Gull shows the gnarly black bill that you see frequently in 3rd winter birds. I have one pic of similar bill in a bird I aged as 4th winter, which is the plumage I think this bird is attaining given the white tip to the fresh P8 and weathered black P9 and P10.

Next is probably a Kumlien's Iceland Gull (but conceivably a Thayer's intergrade)
It has pale slate markings on most of the primaries (it only briefly stretched its wings back), much too pale for a Thayer's. It does have more head streaking than what's typically illustrated in the guides, however, both Howell and Dunn and Olsen and Larsson show photographs of birds with an equal, or more, head streaking. A 1991 paper by Kevin Zimmer reviewing Kumlien's ID in Birding magazine states that possibly up to 20% (though probably less) of Kumlien's Iceland gulls can have dark eyes.

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