San Diego County, California, US
there was a large number of gull/tern like birds flying and diving, not sure whether they were really all the same species
Sterna is a genus of terns in the bird family Sternidae. It used to encompass most "white" terns indiscriminately, but mtDNA sequence comparisons have recently determined that this arrangement is paraphyletic (Bridge et al., 2005). It is now restricted to the typical large white terns occurring near-globally in coastal regions.