Forster's Tern or Sterna forsteri II
and in the background we have California Gulls easily showing the size difference. The Forster's Tern are much smaller. These seem to be a mated pair cause they stayed together the whole time. Interestingly, the right one is in Summer plumage while the right one is in Winer according to my "Stokes Field Guide To Birds" Western Region
NIKON CORPORATION NIKON D300, f/8 @ 800 mm, 1/1600, ISO 400, No Flash
Copyright © Lil Judd aka LilKnytt Photography 2008