Geographic Range
The last great auk was seen in 1852 off the Newfoundland Banks. They were extinct
in the western Atlantic before 1800 and persisted a bit longer in some parts of the
eastern Atlantic and off the coast of Iceland. They lived and bred on scattered, offshore
islands in the northern Atlantic in recorded history, although it is possible they
once occurred on continental coastlines but were extirpated from those areas earlier.
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.
Archeological records indicate they once occurred as far south as southern Spain and
New England in the United States, Pleistocene records indicate great auks occurred
as far south as Italy and other parts of the Mediterranean. Great auks became extinct
before any natural history studies were conducted, so little is known about their
lives except for a few studies of lone, captive birds and the casual records of mariners.
- Biogeographic Regions
- atlantic ocean
Habitat
In recorded history, great auks were found breeding only on isolated, rocky islands
in the North Atlantic. They foraged in the open ocean when not breeding.
- Habitat Regions
- temperate
- polar
- saltwater or marine
Physical Description
Great auks were large, flightless seabirds. They were similar in overall appearance
to their smaller relatives in the family
Alcidae
, but much larger and with greatly reduced wings, reflecting their flightlessness.
Great auks are widely considered the northern Atlantic ecological corollary to the
Antarctic penguins. Great auks stood 70 cm tall and weighed up to 5 kg. They had black
plumage dorsally, with white breasts, bellies, and undertail coverts. Their wings
had a white trailing edge and there was a large white patch in front of each eye.
Their bills were robust and ridged, like other
alcids
, and their gape was bright yellow. Their reduced wings were approximately the size
of those of
razorbills
and were used to propel themselves underwater during dives. They are said to have
been excellent swimmers, able to evade capture by people in boats. Analysis of bones
from midden sites indicates that there may have been some geographical variation in
morphology.
- Other Physical Features
- endothermic
- homoiothermic
- bilateral symmetry
Reproduction
There are no reported of mating behaviors. Based on patterns of parental investment,
great auks were monogamous and may have retained mates over many successive years.
- Mating System
- monogamous
Because they couldn't fly, potential breeding sites had to be accessible from the
sea so that great auks could land and walk from the shore to a nesting site. They
bred in dense congregations in nesting colonies but colonies seem to have relatively
fewer birds than seabirds with smaller body sizes. They are thought to have bred from
May through June, during a breeding window of approximately 6 to 7 weeks. However,
other records indicate breeding occurring later, into August. This could represent
geographic variation, re-nesting, or inaccurate observations. Females laid a single
egg up to 84 by 140 mm in size. Incubation time is estimated at 44 days. Great auks
may have had an exceptionally rapid hatchling development stage, fledging in as little
as 9 days. This is supported by the fact that there are few or now descriptions of
great auk hatchlings or hatchlings held in collections. It is possible that this rapid
hatching to fledging period was followed by parental care on the water, where the
family could forage and fulfill their high energy needs. Estimates suggest they may
have taken 4 to 7 years to reach sexual maturity.
- Key Reproductive Features
- iteroparous
- seasonal breeding
- gonochoric/gonochoristic/dioecious (sexes separate)
- sexual
- oviparous
Females invested heavily in large, yolk-rich eggs and it is thought that great auks
hatched at a fairly precocial state. Both parents developed brood patches, so incubated
eggs and brooded their young. They probably alternated egg and hatchling tending duties,
as in other seabirds. Time to fledging is estimated to be very short, but a post-fledging
period of parental investment at sea is possible.
- Parental Investment
- precocial
-
pre-fertilization
- provisioning
-
protecting
- female
-
pre-hatching/birth
-
provisioning
- female
-
protecting
- male
- female
-
provisioning
-
pre-weaning/fledging
-
provisioning
- male
- female
-
protecting
- male
- female
-
provisioning
Lifespan/Longevity
As in other large seabirds, annual survival is thought to have been relatively high.
Estimated lifespan was from 20 to 25 years.
Behavior
Great auks are thought to have spent most of their time at sea outside of the breeding
season, when they would be found at breeding colonies on isolated, rocky islands and
sea stacks. They were social, foraging in small groups and breeding together in colonies.
Anecdotes suggest that they may have engaged in some kinds of visual displays, including
head shaking and bowing and presenting their bright yellow gapes.
- Key Behaviors
- natatorial
- diurnal
- motile
- nomadic
- social
Home Range
There are no estimates of home range size in the literature, although they are thought to have ranged widely outside of the breeding season.
Communication and Perception
Observations suggest great auks may have used visual displays in communication. Sounds
are not described.
- Communication Channels
- visual
Food Habits
Great auk adults dove for fish and young birds are thought to have eaten zookplanton
or smaller fish. Their morphology and flightlessness indicate they were highly specialized
piscivores as adults. An analysis of the fish bones associated with great auk bones
from middens indicate that they ate fish from 140 to 190 mm long, including menhaden
(
Brevoortia tyrannus
), shad (
Alosa
species), capelin (
Mallotus villosus
), 3-spined sticklebacks (
Gasterosteus aculeatus
), striped sea bass (
Morone saxatilis
), and flatish (
Pleuronectidae
). Based on these evidence, some researchers have suggested that great auks fed mainly
in shallow waters (up to 18 m) within 2 km of shore and chose primarily large prey
(70 to 190 mm, up to 300 mm). They seem to have preferred fish with high fat content.
- Animal Foods
- fish
- zooplankton
Predation
Great auks were preyed on by humans. Other natural predators are not known.
Ecosystem Roles
Great auks were specialized predators of larger fish in the northern Atlantic.
Economic Importance for Humans: Positive
Great auk bones are common in coastal middens throughout Europe and the Mediterranean
dating from 13,000 to 2,000 years before present. Great auks were intensively exploited
for food and fuel by mariners in search of fresh meat. Their fat was also rendered
and used as fuel.
- Positive Impacts
- food
- body parts are source of valuable material
Economic Importance for Humans: Negative
There are no adverse effects of great auks on humans.
Conservation Status
Great auks are presumed to have become extinct in 1852, the last date that a wild
bird was observed. The last known breeding pair was killed in 1844 in Iceland. Great
auks, and their eggs and young, were relentlessly exploited for food and fuel. Like
other flightless birds with few or no natural predators, such as dodos (
Raphus cucullatus
), great auks were docile and ungainly on land. They could not fly and could only
walk at about the pace of a human walking. They did not exhibit fear when approached
and were therefore easily captured and dispatched. Mariners raided nesting colonies
and took birds and eggs by the thousands to eat fresh, render for fuel, or salt for
later consumption. The last two birds killed in Iceland were preserved and are held
in the Museum of Zoology in Copenhagen, Denmark. There is little doubt that they were
hunted to extinction by humans, although there is a possibility that their numbers
and range were declining previous to that as a result of environmental changes that
reduced the number of appropriate islands for breeding and altered prey abundance.
Prehistoric human hunters seem to have sustainably hunted great auks and some modern
human populations imposed regulations to moderate the effect of their harvesting on
populations.
Other Comments
Great auks were also known as "garefowl" and were previously known under the name
Alca impennis
.
Additional Links
Contributors
Tanya Dewey (author), Animal Diversity Web.
- Atlantic Ocean
-
the body of water between Africa, Europe, the southern ocean (above 60 degrees south latitude), and the western hemisphere. It is the second largest ocean in the world after the Pacific Ocean.
- native range
-
the area in which the animal is naturally found, the region in which it is endemic.
- temperate
-
that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).
- polar
-
the regions of the earth that surround the north and south poles, from the north pole to 60 degrees north and from the south pole to 60 degrees south.
- saltwater or marine
-
mainly lives in oceans, seas, or other bodies of salt water.
- pelagic
-
An aquatic biome consisting of the open ocean, far from land, does not include sea bottom (benthic zone).
- coastal
-
the nearshore aquatic habitats near a coast, or shoreline.
- endothermic
-
animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.
- bilateral symmetry
-
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.
- monogamous
-
Having one mate at a time.
- iteroparous
-
offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).
- seasonal breeding
-
breeding is confined to a particular season
- sexual
-
reproduction that includes combining the genetic contribution of two individuals, a male and a female
- oviparous
-
reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.
- young precocial
-
young are relatively well-developed when born
- natatorial
-
specialized for swimming
- diurnal
-
- active during the day, 2. lasting for one day.
- motile
-
having the capacity to move from one place to another.
- nomadic
-
generally wanders from place to place, usually within a well-defined range.
- social
-
associates with others of its species; forms social groups.
- visual
-
uses sight to communicate
- zooplankton
-
animal constituent of plankton; mainly small crustaceans and fish larvae. (Compare to phytoplankton.)
- food
-
A substance that provides both nutrients and energy to a living thing.
- carnivore
-
an animal that mainly eats meat
- piscivore
-
an animal that mainly eats fish
- visual
-
uses sight to communicate
- tactile
-
uses touch to communicate
- acoustic
-
uses sound to communicate
- chemical
-
uses smells or other chemicals to communicate
References
Bengston, S. 1984. Breeding ecology and extinction of the great auk (Pinguinus impennis): anecdotal evidence and conjectures.. The Auk , 101: 1-12.
BirdLife International 2008, 2009. "Pinguinus impennis" (On-line). IUCN Red List of Threatened Species. Version 2009.1. Accessed July 11, 2009 at http://www.iucnredlist.org/details/144282/0 .