The family Alcidae includes 22 species found in North America.

Alcids live almost their entire lives on the ocean. They come to shore only to nest, usually in burrows or rock crevices. Their diet is primarily fish and squid caught by diving or chasing them underwater. Wings are more suited for underwater pursuit than for flying. In flight all Alcids have rapid wing beats. All are colored black and white. During the breeding season, some have very colorful beaks. Alcids (found in the Northern hemisphere) fill the same ecological niche that Penguins fill in the Southern hemisphere.