The term 'ocean-diving bird' can be summarized as an AUK, which is a three-letter word. Auks are a group of seabirds that live in the Northern Hemisphere and are adapted for swimming and diving in the ocean. They have short wings and webbed feet, which help them to maneuver underwater. They feed on small fish, crustaceans, and mollusks, which they catch by diving into the water. Auks are also known for their loud calls, which can be heard from far away.