A dead razorbill, St Mary’s Island, Whitley Bay.
The razorbill, razor-billed auk, or lesser auk (Alca torda) is a colonial seabird in the monotypic 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.
In 1918, the razorbill was protected in the United States by the Migratory Bird Treaty Act. Presently, the major threat to the population is the destruction of breeding sites.