The razorbill, razor-billed auk, or lesser auk (Alca torda) is a colonial seabird and the only extant member of the genus Alca of the family Alcidae, the auks. It is the closest living relative of the extinct great auk (Pinguinis impennis). Wild populations live in the subarctic waters of the Atlantic Ocean. Razorbills are primarily black with a white underside. The male and female are identical in plumage; however, males are generally larger than females. This agile bird, which is capable of both flight and diving, has a predominantly aquatic lifestyle and only comes to land in order to breed. It is monogamous, choosing one partner for life. Females lay one egg per year. Razorbills nest along coastal cliffs in enclosed or slightly exposed crevices. The parents spend equal amounts of time incubating, and once the chick has hatched, they take turns foraging for their young. (Source: Wikipedia.org, CC BY-SA)