UKBirds

Great Auk

Pinguinus impennis

The Great Auk, formerly of the genus Alca, was a large, flightless alcid that became extinct in the mid-19th century. It was the only modern species in the genus Pinguinus, a group of birds that formerly included one other species of flightless giant auk from the Atlantic Ocean region. It bred on rocky, isolated islands with easy access to both the ocean and a plentiful food supply, a rarity in nature that provided only a few breeding sites for the auks. When not breeding, the auks spent their time foraging in the waters of the North Atlantic, ranging as far south as New England and northern Spain through Canada, Greenland, Iceland, the Faroe Islands, Norway, Ireland, and Great Britain.

The Great Auk was 75 to 85 centimetres (30 to 33 in) tall and weighed around 5 kilograms (11 lb), 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, the Great Auk had a white patch over each eye. During winter, the auk lost this patch, instead developing a white band stretching between the eyes. The wings were 15 centimetres (5.9 in) long, rendering the bird flightless. Instead, the auk was a powerful swimmer, a trait that it used in hunting. Its favorite prey were fish, including Atlantic Menhaden and Capelin, and crustaceans. Although agile in the water, it was clumsy on land. Its main predators were Orcas, White-tailed Eagles, Polar Bears, and humans. Great Auk pairs mated for life. They nested in extremely dense and social colonies, laying one egg on bare rock. The egg was white with variable brown streaking. Both parents incubated for about six weeks before their young hatched. The young auks left the nest site after two or three weeks and the parents continued to care for them.

Humans had hunted the Great Auk for more than 100,000 years. It was an important part of many Native American cultures which coexisted with the bird, both as a food source and as a symbolic item. Many Maritime Archaic people were buried with Great Auk bones, and one was buried covered in over 200 auk beaks, which are assumed to have been part of a cloak made of their skins. Early European explorers to the Americas used the auk as a convenient food source or as fishing bait, reducing its numbers. The bird's down was in high demand in Europe, a factor which largely eliminated the European populations by the mid-16th century. Scientists soon began to realize that the Great Auk was disappearing and it became the beneficiary of many early environmental laws, but this proved not to be enough. Its growing rarity increased interest from European museums and private collectors in obtaining skins and eggs of the bird. This trend eliminated the last known breeding attempt, and the last certain record, of the Great Auks on 3 July 1844 on Eldey, Iceland, but there are unconfirmed later reports of roaming individuals being seen or caught. A record of a bird in 1852 is considered by some to be the last sighting of this species. The Great Auk is mentioned in a number of novels and the scientific journal of the American Ornithologists' Union is named The Auk in honour of this bird.Standing about 75 to 85 centimetres (30 to 33 in) tall and weighing around 5 kilograms (11 lb), the flightless Great Auk was the largest of both its family and the order Charadriiformes. The auks which lived further north averaged larger in size than the more southerly members of the species. Males and females were similar in plumage, although there is evidence for differences in size, particularly in the bill and femur length. The back was primarily a glossy black, while the stomach was white. The neck and legs were short, and the head and wings small. The auk appeared chubby due to a thick layer of fat necessary for warmth. During summer, the Great Auk developed a wide white eye patch over the eye, which had a hazel or chestnut iris. During winter the auk molted and lost this eye patch, which was replaced with a wide white band and a gray line of feathers which stretched from the eye to the ear. During the summer, the auk's chin and throat were blackish-brown, while the inside of the mouth was yellow. During the winter, this alcid molted and the throat became white. Some individuals had grey plumage on their flanks, but the purpose of this is unknown. The bill was large at 11 centimetres (4.3 in) long and curved downwards at the top; the bill also had deep white grooves in both the upper and lower mandibles, up to seven on the upper mandible and twelve on the lower mandible in summer, though there were fewer in winter. The wings were only 15 centimetres (5.9 in) in length and the longest wing feathers were only 10 centimetres (3.9 in) long. Its feet and short claws were black while the webbed skin between the toes was brownish black. The legs were far back on the bird's body, which gave it powerful swimming and diving abilities.

Hatchlings were gray and downy, but their exact appearance is unknown, since no skins exist today. Juvenile birds had less prominent grooves in their beaks and had mottled white and black necks, while the eye spot found in adults was not present; instead, a gray line ran through the eyes (which still had the white eye ring) to just below the ears.

The auk's calls included low croaking and a hoarse scream. A captive auk was observed making a gurgling noise when anxious. It is not known what its other vocalizations were like, but it is believed that they were similar to those of the Razorbill, only louder and deeper.