Thursday, December 27, 2012

Mewsings

I took these photos at Doran Beach on 15 December 2012, but haven't had a chance to post them until now.  Do you recognize this gull?


Mew Gulls (Larus canus) are relatively small gulls with long wings.  Note the rounded head, short and slender bill, and relatively large, dark eye.

The color of the bill and legs varies from gray-green to green-yellow.  Here's an individual on the gray-green end of the spectrum.


The next image shows the range in leg color between two birds standing next to each other.  Also note how the shape of the head can look different depending on whether the neck is extended or pulled in.


Although Mew Gull eyes often appear very dark, occasionally individuals show pale yellow eyes (next image).


Fourteen species of gulls have been documented on Bodega Head (for this number, I'm only including species with "gull" in their common name).  Ring-billed Gulls (Larus delawarensis) can look somewhat similar to Mew Gulls, but side-by-side it's easy to pick out some of the differences.

In the next two pictures, compare the following:

- overall appearance (Mew Gulls are more delicate)
- bill (Ring-billed Gulls have a more robust bill with an obvious black ring near the tip of the bill)
- mantle or back color (Mew Gulls are slightly darker gray)
- white spots on primary feathers (Mew Gulls show larger white spots) 
- tertial crescent (the white "patch" between the gray back and black wing tips; it's wider and more obvious in Mew Gulls)



Mew Gulls winter along the Pacific Coast, so you can see them in the Bodega Bay area from fall through spring (most depart by the end of April, heading north to breed in northwest Canada and Alaska).


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