16 August 2012

String of Pearls

Gulls never seize to amaze me. Besides the incredible amount of variation found on the species level, there are enough aberrations to be found in almost any flock of your most common species.

Here's an interesting juvenile American Herring Gull with what looks like a series of pearls all across the subterminal tips to the primaries and greater primary coverts:

Juvenile American Herring Gull. Chicago, IL. 15 August 2012.
I'm not really sure what this is caused by. The closest thing I could relate it to is a fault bar, but not exactly.

Juvenile American Herring Gulls have been out and about for a couple of weeks now on the Chicago lakefront. This species is our only other summering gull, found in much smaller numbers than Ring-billeds.

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