This is a Great Blue Heron fishing during low tide at the bay. He just caught a small fish, and now he is shaking and flipping the fish to position the fish head first before swallowing. A bird that eats fish whole will orient a fish head first when swallowing it so that the fins can't expand and injure the bird's esophagus on the way down.

Nikon P1000

Shadow highlights HDR and PS