Sterna sandvicensis

Sandwich Tern with juvenile at Lovers Key State Park at New Pass
Fort Myers Beach, Florida USA

I'm going to speculate that this tern was injured by a Laughing Gull which
I've observed attempting to steal fish from the terns quite often. The pass of
fish from the beak of an adult tern to the juvenile happens extremely
fast perhaps to avoid confrontation with the Laughing Gull.