Great Auk

The great auk (Pinguinus impennis) was a flightless seabird, belonging to the family Alcidae, once abundant in the North Atlantic, ranging from Newfoundland to Norway, and as far south as northern Spain. Although often compared to penguins due to its appearance and inability to fly, the great auk was not closely related to them.

This article will examine the natural history of the great auk, including its physical characteristics, diet, breeding behavior, and historical distribution. Furthermore, it will explore the factors that contributed to its extinction in the mid-19th century, highlighting the role of human exploitation and the broader implications for conservation biology.

Appearance

The great auk’s most striking feature was its inability to fly, a characteristic that ultimately contributed to its extinction. Its short and stubby wings were powerfully built and adapted for swimming. They measured only about 15 cm (6 inches) long, functioned like flippers, propelling the auk underwater with remarkable speed and agility. Its dense bones, another adaptation for diving, provided buoyancy control.

Its beak was large and slightly hooked, possessed a unique grooved texture along the edges. These grooves may have aided in gripping slippery prey like fish. During breeding season, the auk’s beak also displayed a colorful rosette-like patch near the base, which faded after the breeding period. This ornamental feature likely played a role in courtship displays.

They had black plumage dorsally, with white breasts, bellies, and undertail coverts.

The feet positioned far back on its body, made them excellent swimmers but resulted in an awkward, upright posture on land. Its webbed feet, equipped with sharp claws, also aided in gripping rocky surfaces during the breeding season, when large colonies gathered on isolated islands.

Here are the words of French explorer Jacques Cartier who described auks and what it was like to kill them, in 1534: 

[…] some of these birds were as large as geese, being black and white with a beak like a crow’s. […] And these birds are so fat it is marvellous… In less than halfe an houre we filled two boats full of them, as if they had been stones, so that besides them that we did eat fresh, every ship did powder and salt five or six barrels full of them […]

The last pair in Great Britain was killed on the islet of Stac, an Admin in Scotland, in 1844. It was caught and kept alive for three days until a dangerous storm began to threaten the three men from St Kilda who captured it. In an attempt to save their own lives and stop the storm, the men beat the last great auk to death with a stick, determining that it was a witch intent on drowning them. They were preserved and held in the Museum of Zoology in Copenhagen, Denmark.

Habitat

Their habitat consisted primarily of isolated, rocky islands in the North Atlantic Ocean. The auks preferred islands with sloping shorelines and nearby shallow waters, facilitating easy access to and from the sea. While at sea, they inhabited cold, nutrient-rich waters teeming with fish, their primary food source.

They were found from Canada, Greenland, and Iceland to the British Isles and Scandinavia. Colonies in the western Atlantic may have been less numerous than in the eastern Atlantic. Historically, their range may have extended as far south as northern Spain and Italy.

During the non-breeding season, these seabirds dispersed further south, reaching waters off New England and western Europe, including the British Isles and France. Fossil evidence suggests an even wider historical distribution, including areas in the Mediterranean.

Diet

The diet consisted primarily of fish, supplemented by crustaceans and other small marine invertebrates. While the exact species consumed varied depending on location and availability, common prey likely included fish like capelin, sand lance, and Atlantic cod, as well as crustaceans like krill and amphipods.

The auk’s powerful swimming abilities and diving prowess allowed it to pursue prey underwater, using its wings as flippers to navigate and its sharp beak to capture its meals. Analysis of skeletal remains and preserved stomach contents has provided insights into their diet, confirming the predominance of fish and other small marine organisms.

Reproduction

Great auks were colonial breeders, congregating in large numbers on selected islands during the breeding season, typically between May and June. They returned to the same breeding island year after year. Within these dense colonies, individual pairs formed monogamous bonds, likely for the duration of the breeding season.

The female great auk laid a single, large, pyriform (pear-shaped) egg directly onto bare rock, usually within a slight depression or crevice for protection. The egg’s distinctive markings, varying in color from whitish-yellow to pale ochre with dark brown or black blotches and streaks, made it easily identifiable. Both parents shared incubation duties, alternating turns for approximately 39-44 days.

Once hatched, the chick was covered in downy feathers and remained dependent on its parents for warmth and food. Both parents participated in feeding the chick, primarily with fish brought back from foraging trips at sea. The chick left the colony and became independent, after about 2-3 weeks. The great auk’s relatively low reproductive rate, producing only one chick per year, made them particularly vulnerable to population decline from overhunting.

Threats

The extinction of the great auk resulted directly from human overexploitation. The increased predation during the Little Ice Age reduced the population of the Great Auk by exposing more of their breeding islands to predation by Polar Bears. The primary cause was unsustainable hunting driven by demand for the auk’s down feathers.

Beginning in the 16th century, European populations were heavily targeted for their down, used in pillow production. Despite some early, albeit limited, protective legislation, hunting continued extensively, especially in North America as eider duck populations declined. This relentless exploitation ultimately led to the great auk’s extinction in the mid-19th century.

5 More Astonishing facts about the Great Auk

1. Great auks had a distinctive, almost penguin-like waddle on land.
2. Sailors sometimes used great auks as live bait for larger fish.
3. The great auk’s closest living relative is the razorbill, a much smaller alcid that can still be found in the North Atlantic.
4. Some scientists believe the great auk’s low reproductive rate played a significant role in its inability to recover from overhunting.
5. Despite being flightless, great auks were incredibly strong swimmers and could dive to depths of up to 250 feet in search of food.

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