Caspian Tern (Hydroprogne caspia)

The first time I saw terns like these I had no telephoto lens with me but that didn't stop me from enjoying their hovering and missile-like diving. The photo above is the second time I saw them out at Esquimalt Lagoon but they were quite far away and mostly obscured by the many seagulls surrounding them. I am not 100% certain of my identification of these birds as Caspian Terns. They are the birds in this photo with the large red bills. The distinguishing feature that I think identifies them as Caspian Terns is the black feet and legs visible on the tern just coming in for a landing in this photo.