The Great Auk, Pinguinus impennis, formerly of the genus Alca, is a bird that became extinct in the mid-19th century. It was the only species in the genus Pinguinus, a group which included several flightless giant auks from the Atlantic, to survive until modern times. It was also known as garefowl (from the Old Norse geirfugl, meaning "spear-bird", a reference to the shape of its beak), or penguin (before the birds known by that name today were so called).

The Great Auk was found in great numbers on islands off eastern Canada, Greenland, Iceland, Norway, Ireland and Great Britain before eventually being hunted to extinction. Remains found in Floridian middens suggest that, at least occasionally, the Great Auk ventured that far south in winter as recently as the 14th century.

Taxonomy Great Auk, Leipzig

The Great Auk was one of the many species originally described by Linnaeus in his 18th century work, Systema Naturae.

Analysis of mtDNA sequences have confirmed morphological and biogeographical studies in regarding the Razorbill as the Great Auk's closest living relative. They were also closely related to the Little Auk (Dovekie), which underwent a radically different evolution compared to Pinguinus, although the entire lineage seems to have evolved in the North Atlantic. Due to its outward similarity to the razorbill (apart from flightlessness and size), the Great Auk was often placed in the genus Alca.

However, the fossil record (Pinguinus alfrednewtoni from the Early Pliocene Yorktown Formation of the Lee Creek Mine, USA) and molecular evidence demonstrate that the three genera, while still closely related, diverged soon after their common ancestor (probably similar to a stout Xantus's Murrelet) had spread to the coasts of the Atlantic. By that time however, the murres, or Atlantic Guillemots had apparently already split off from the other Atlantic alcids. Razorbill-like birds were common in the Atlantic during the Pliocene, but the evolution of the Dovekie is sparsely documented.

The molecular data are compatible with either view, but the weight of evidence suggests placing the Great Auk in a distinct genus.

Description Great Auks by John James Audubon

Standing about 75-85 cm (30-34 in) tall and weighing around 5 kg (11 lb), the flightless Great Auk was the largest of the auks. It had white lower- and glossy black upper feathers, with an area of white feathers on both sides of the head between the beak and each eye. The longest wing feathers were only 10 cm (3.9 in) long. The eyes had a reddish/brown iris, and the beak was black with white transverse grooves. Its feet and claws were black while the webbed skin between the toes was brown/black. Juvenile birds had less prominent grooves in their beaks and had mottled white and black necks.

Behaviour Great Auk eating a fish, by John Gould.

Great Auks were excellent swimmers, using their wings to swim underwater. Their main food was fish, usually 12-20 cm in length, but occasionally up to half the bird's own length. Based on remains associated with Great Auk bones found on Funk Island and on ecological and morphological considerations, it seems that Atlantic menhaden and capelin were favored prey items.

Great Auks walked slowly and sometimes used their wings to help them traverse rough terrain. They had few natural predators, mainly large marine mammals and birds of prey, and had no innate fear of humans. Their flightlessness and awkwardness on land compounded their vulnerability to humans, who hunted them for food, feathers, and as specimens for museums and private collections.

The Great Auk laid only one egg each year, which it incubated on bare ground until hatching in June. The eggs averaged 12.4cm (4.9in) in length, and were yellowish white to light ochre with a varying pattern of black, brown or greyish spots and lines which often congregated on the large end.

Extinction Egg, Ipswich Museum, Suffolk

The Great Auk was hunted on a significant scale for food, eggs and down from at least the 8th century. Prior to that, hunting by local natives can be documented from Late Stone Age Scandinavia and Eastern North America, and from early 5th century Labrador where the bird only seems to have occurred as a straggler. A person buried at the Maritime Archaic site at Port au Choix, Newfoundland, dating to about 2000 BC, seems to have been interred clothed in a suit made from more than 200 Great Auk skins, with the heads left attached as decoration.

Stuffed Great Auk, Belgium.

The Little Ice Age may have reduced their numbers, but massive exploitation for their down drastically reduced the population. Specimens of the Great Auk and its eggs became collectible and highly prized, and collecting of the eggs contributed to the demise of the species.

On Stac an Armin, St Kilda, Scotland, in July, 1840, the last Great Auk seen in the British Isles was killed by two St Kildan residents. Haswell-Smith claims that this was because they thought it was a witch.

The last population lived on Geirfuglasker ("Great Auk Rock") off Iceland. This island was a volcanic rock surrounded by cliffs which made it inaccessible to humans, but in 1830 the rock submerged, and the birds moved to the nearby island Eldey which was accessible from a single side. The last pair, found incubating an egg, were killed there on 3 July 1844, with Jón Brandsson and Sigurður Ísleifsson strangling the adults and Ketill Ketilsson smashing the egg with his boot. However, 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 (IUCN).

Today, around 75 eggs of the Great Auk remain in museum collections, along with 24 complete skeletons and 81 mounted skins. While thousands of isolated bones have been collected from 19th century Funk Island to Neolithic middens, only a minute number of complete skeletons exist.

In popular culture Mounted specimen, Natural History Museum, London

The Great Auk is the mascot of Archmere Academy in Claymont, Delaware, USA; Sir Sandford Fleming college in Ontario, Canada; and the Adelaide University Choral Society (AUCS), Australia. It is also the mascot of the Knowledge Masters educational competition.

The Auk, the scientific journal of the American Ornithologists' Union, is named after this bird.

According to Homer Hickam's memoir Rocket Boys and its subsequent film production October Sky, the early rockets he and his friends built were named "Auk" along with a sequential numeration as an obvious display of irony.

Engraving by George Edward Lodge

The Great Auk is the subject of a novel, The Last Great Auk by Allen Eckert, which tells of the events leading to the extinction of the Great Auk as seen from the perspective of the last one alive.

A Great Auk (presumably stuffed) appears among the possessions of Baba the Turk in the opera The Rake's Progress by Igor Stravinsky.

In the novel adaptation of The Wicker Man by Robin Hardy & Anthony Shaffer, the (fictitious) Summerisle is revealed to be home to a surviving colony of Great Auks.

The Two Ronnies enacted a parody on BBC TV entitled "Raiders of the Lost Auk", in which an archaeologist tracks down a golden auk, pursued by Nazis.

The Great Auk is a significant factor in the children's book The Island of Adventure by Enid Blyton. Jack is a keen ornithologist, and believes that the mysterious Island of Gloom may host a surviving Great Auk. This belief leads the children to the island, where they don't find a Great Auk but do find adventure.

The Great Auk is also the subject of a Ballet called Still Life at the Penguin Café.