The Great Auk (Pinguinus impennis) was a large, flightless bird of the alcid family that became extinct in the mid-19th century. The Great Auk was 30 to 33 inches tall and weighed around 11 pounds, making it the largest member of the alcid family. It had a black back and a white belly. The black beak was heavy and hooked with grooves on its surface. During summer, it had a white patch over each eye. During winter, it lost these patches, instead developing a white band stretching between the eyes. The wings were only 6 inches long, rendering the bird flightless. It was a powerful swimmer, a trait that it used in hunting, as their main food was fish. Although agile in the water, it was clumsy on land. Great Auk pairs mated for life. The last pair, found incubating an egg, were killed on July 3, 1844, on request from a merchant who wanted specimens. A later claim of a live individual sighted in 1852 on the Grand Banks of Newfoundland has been accepted by the International Union for Conservation of Nature and Natural Resources.