Forster's Tern
Forster's Tern Sterna forsteri
Shooting with Don Metzner (aka hearman) in my local patch

I thought this was a handoff to a chick. Zifu Bob Power informs me that these are two adults:

"Adult to adult. juvenile would not have black cap, and should have a lot of rust still. Excellent capture of a guy showing off for a girl."
"When you have eliminated the impossible, whatever remains, however improbable, must be the truth."

Wandering through my new Audubon Pacific Coast field guide, I suspect the very fresh, very alive, fish is a Northern Anchovy.

Focal length: 700 mm fStop: 11 ISO: 400 Shutter Speed: 1/1600
Redwood City, CA - Radio Road Ponds
May 15, 2009