The rhinoceros auklet (Cerorhinca monocerata) name is derived from a horn-like extension of the beak which is only present in breeding adults, and like the elaborate sheath on the bill of puffins is shed every year. The Rhinoceros Auklet is actually a puffin, not an auklet, and is the only living species of the genus Cerorhinca. A regular diver on the northern Pacific Coast of the US, it is found on the open sea and coastlines where it is a fast flier and may fly long distances to feeding areas daily. The diet consists primarily of small fish, but also crustaceans and cephalopods (squid). It breeds from California to the Aleutian Islands in Alaska in North America; and Hokkaido and Honshu, Japan, as well as North Korea and Sakhalin Island in Asia.