Greater Black-backed Gull 4-25-2012

The photos below are digiscope photos of a gull at Hoover Reservoir on April 25, 2012. I believe this is a third year Greater Black-backed Gull, but I have very little experience with Gulls. I would like comments from those with expertise in this area.

Unfortunately I was unable to get any better photos. The bird was preening, and when I had a side view the bird hid its head every time I took a photo.  Hopefully the photos are sufficient to ID the bird, however.

Note the pale pink legs, which I noticed while viewing the bird. Also note that in several of the photos there is a Herring Gull in front of the subject bird.