Photo by Dennis Ghiglieri.
This photo shows both the adult Lesser Black-backed Gull (far right, with Ring-billed Gull)
and what was, at the time, a still-unidentified large dark gull, far left.
The then-unidentified dark gull is now endorsed by the NBRC as Nevada's earliest Lesser Black-backed Gull.
Additional photos of that bird are available on the ID Issues/Rarities page as "Lesser Black-backed Gull, Second-cycle..."
Photo by Dennis Ghiglieri.
Flight photo.
Photo by Dennis Ghiglieri.
Flight photo. I think the other bird is a Ring-billed Gull, but I'm not sure.
Notice the "mirror" on the outermost primary feather, the all white tail, and the yellow eyes.
Bill pattern is hard to make out precisely.
Notice also that the outermost primary is not fully grown.
Photo by Greg Scyphers.
Exposure makes the bird appear darker than it was, but the photo
shows the yellow legs along with other features.
Especially, note the very long wings.
Photo by Greg Scyphers.
Different exposure makes bird appear much lighter. (This is closer to what it looked like.)
Even with bird angled away, the long-winged appearance is obvious.