Aethia
Encyclopedia
Aethia is a genus
of four small (85-300g) auk
lets endemic to the North Pacific Ocean
, Bering Sea
and Sea of Okhotsk
and among some of North America
's most abundant seabirds. The relationships between the four true auklets remains unclear. Auklets are threatened by invasive species such as Arctic Fox
es (Alopex lagopus) and Norway Rats (Rattus norvegicus) because of their high degree of coloniality and crevice-nesting.
The genus Aethia occurs only in the North Pacific and adjacent waters, mainly in the Bering Sea
region. Along with Cassin's Auklet
(Ptychoramphus aleuticus) they comprise the monophyletic
tribe Aethinii. Molecular work has not yet resolved the relationship between the Aethia auklets, but the group is a sister group to Cassin's Auklet
, which is, in turn, a sister group to the Fraterculine auks (puffins and Rhinoceros Auklet
).
The genus
Aethia did not enter into widespread use until the 1960s. Initially, the auklets were placed in Alca
, but later reorganized into genera including: Simorhynchus, Phaleris and Cyclorhynchus. Cyclorhynchus is still occasionally used for the Parakeet Auklet
.
(15 million years ago). The first Aethia fossils date from the late Miocene
(10-15 million years ago) and the four species likely diverged rapidly about 5 million years ago.
There are one or two fossil species which lived in the area of today's California
during the Late Miocene
, some 5 million years ago: Aethia rossmoori (Monterrey Formation of Orange County
) and an undescribed taxon
tentatively placed in this genus.
ing breeding auklets can be difficult because they nest in hidden crevices. At present, population estimates are:
and Sea of Okhostk with notable Asia
n colonies in the Kuril Islands
, Commander Islands, along the Kamchatka
and Chukota Peninsulas
. In North America
, large colonies are in the Aleutian Islands (Buldir, Kiska
, Semisopochnoi and Gareloi
) to the Gulf of Alaska
and north to the islands of the Bering Sea
(St. Lawrence Island
, Pribilof Islands
, St. Matthew Island
).
Auklets are have high site fidelity
, at both the colony and crevice level, although there can be a high divorce
rate of up to 33% in Least and Crested Auklets when both mates survive.
s are more dispersed). All have some form of facial ornamentation such as large crests (Whiskered
and Crested Auklet
s), auricular plumes (all four species), and Crested
and Whiskered Auklet
s have a tangerine-scented odour which may function in mate choice or species recognition, although this requires more study.
All Aethia auklets lay one white egg in a natural crevice and incubate for 25–36 days, after which, a semi-precocial chick emerges and fledge
s after 25–35 days. Age at first breeding is estimated at 3–5 years. Colony sizes
are highly variable, and range from less than 100 individuals to over 1 million, although Least
and Crested Auklet
s tend to nest in greater density than Parakeet
and Whiskered Auklet
s.
s, euphausiids
and other invertebrate
s such as jellyfish
and ctenophores. Winter diet has not been studied.
, and have been extirpated from some islands that contained Arctic Fox
es introduced for farming. Eradication of rats from Rat Island
was completed in 2008 and 2009.
The large colony at Sirius Point, Kiska Island
, Alaska
(perhaps the largest auklet colony in the world) experienced almost complete breeding failure in 2001 and 2002 because of rat predation and disturbance and has been the focus of researchers at Memorial University of Newfoundland
.http://www.mun.ca/serg/Kiska2002.html
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of four small (85-300g) auk
Auk
An auk is a bird of the family Alcidae in the order Charadriiformes. Auks are superficially similar to penguins due to their black-and-white colours, their upright posture and some of their habits...
lets endemic to the North Pacific Ocean
Pacific Ocean
The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...
, Bering Sea
Bering Sea
The Bering Sea is a marginal sea of the Pacific Ocean. It comprises a deep water basin, which then rises through a narrow slope into the shallower water above the continental shelves....
and Sea of Okhotsk
Sea of Okhotsk
The Sea of Okhotsk is a marginal sea of the western Pacific Ocean, lying between the Kamchatka Peninsula on the east, the Kuril Islands on the southeast, the island of Hokkaidō to the far south, the island of Sakhalin along the west, and a long stretch of eastern Siberian coast along the west and...
and among some of North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
's most abundant seabirds. The relationships between the four true auklets remains unclear. Auklets are threatened by invasive species such as Arctic Fox
Arctic fox
The arctic fox , also known as the white fox, polar fox or snow fox, is a small fox native to Arctic regions of the Northern Hemisphere and is common throughout the Arctic tundra biome. The Greek word alopex, means a fox and Vulpes is the Latin version...
es (Alopex lagopus) and Norway Rats (Rattus norvegicus) because of their high degree of coloniality and crevice-nesting.
Taxonomy and Evolution
Bering Sea
The Bering Sea is a marginal sea of the Pacific Ocean. It comprises a deep water basin, which then rises through a narrow slope into the shallower water above the continental shelves....
region. Along with Cassin's Auklet
Cassin's Auklet
The Cassin’s Auklet is a small, chunky seabird that ranges widely in the North Pacific. It nests in small burrows and because of its presence on well studied islands in British Columbia and off California it is one of the better known auks...
(Ptychoramphus aleuticus) they comprise the monophyletic
Monophyly
In common cladistic usage, a monophyletic group is a taxon which forms a clade, meaning that it contains all the descendants of the possibly hypothetical closest common ancestor of the members of the group. The term is synonymous with the uncommon term holophyly...
tribe Aethinii. Molecular work has not yet resolved the relationship between the Aethia auklets, but the group is a sister group to Cassin's Auklet
Cassin's Auklet
The Cassin’s Auklet is a small, chunky seabird that ranges widely in the North Pacific. It nests in small burrows and because of its presence on well studied islands in British Columbia and off California it is one of the better known auks...
, which is, in turn, a sister group to the Fraterculine auks (puffins and Rhinoceros Auklet
Rhinoceros Auklet
The Rhinoceros Auklet is a seabird and a close relative of the puffins. It is the only living species of the genus Cerorhinca. Given its close relationship with the puffins, the common name Rhinoceros Puffin has been proposed for the species.It ranges widely across the North Pacific, feeding on...
).
The genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
Aethia did not enter into widespread use until the 1960s. Initially, the auklets were placed in Alca
Razorbill
The Razorbill is colonial seabird that will only come to land in order to breed. It is the largest living member of the Auk family. This agile bird will choose only one partner for life and females will lay one egg per year. Razorbills will nest along coastal cliffs in enclosed or slightly exposed...
, but later reorganized into genera including: Simorhynchus, Phaleris and Cyclorhynchus. Cyclorhynchus is still occasionally used for the Parakeet Auklet
Parakeet Auklet
The Parakeet Auklet is a small seabird of the North Pacific. It used to be placed on its own in the genus Cyclorrhynchus but recent morphological and genetic evidence suggest it should be placed in the genus Aethia. It is associated with the boreal waters of Alaska and Kamchatka and Siberia...
.
Fossil record
The first undisputed auk fossils are from the middle MioceneMiocene
The Miocene is a geological epoch of the Neogene Period and extends from about . The Miocene was named by Sir Charles Lyell. Its name comes from the Greek words and and means "less recent" because it has 18% fewer modern sea invertebrates than the Pliocene. The Miocene follows the Oligocene...
(15 million years ago). The first Aethia fossils date from the late Miocene
Miocene
The Miocene is a geological epoch of the Neogene Period and extends from about . The Miocene was named by Sir Charles Lyell. Its name comes from the Greek words and and means "less recent" because it has 18% fewer modern sea invertebrates than the Pliocene. The Miocene follows the Oligocene...
(10-15 million years ago) and the four species likely diverged rapidly about 5 million years ago.
There are one or two fossil species which lived in the area of today's California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
during the Late Miocene
Miocene
The Miocene is a geological epoch of the Neogene Period and extends from about . The Miocene was named by Sir Charles Lyell. Its name comes from the Greek words and and means "less recent" because it has 18% fewer modern sea invertebrates than the Pliocene. The Miocene follows the Oligocene...
, some 5 million years ago: Aethia rossmoori (Monterrey Formation of Orange County
Orange County, California
Orange County is a county in the U.S. state of California. Its county seat is Santa Ana. As of the 2010 census, its population was 3,010,232, up from 2,846,293 at the 2000 census, making it the third most populous county in California, behind Los Angeles County and San Diego County...
) and an undescribed taxon
Taxon
|thumb|270px|[[African elephants]] form a widely-accepted taxon, the [[genus]] LoxodontaA taxon is a group of organisms, which a taxonomist adjudges to be a unit. Usually a taxon is given a name and a rank, although neither is a requirement...
tentatively placed in this genus.
Population Estimates
CensusCensus
A census is the procedure of systematically acquiring and recording information about the members of a given population. It is a regularly occurring and official count of a particular population. The term is used mostly in connection with national population and housing censuses; other common...
ing breeding auklets can be difficult because they nest in hidden crevices. At present, population estimates are:
- Least AukletLeast AukletThe Least Auklet, Aethia pusilla, is a seabird and the smallest species of auk. It is the most abundant seabird in North America, and one of the most abundant in the world, with a population of around nine million birds. They breed on the islands of Alaska and Siberia, and spend the winter close to...
- 20,000,000+ - Whiskered AukletWhiskered AukletThe Whiskered Auklet, Aethia pygmaea, is a small seabird of the auk family. It has a more restricted range than other members of its genus, Aethia, living only around the Aleutian Islands and on some islands off Siberia , and breeding on these islands. It is one of the smallest alcids, only the...
- 100,000 - 250,000 - Crested AukletCrested AukletThe Crested Auklet is a small seabird of the family Alcidae which nests in huge colonies in the Bering Sea and Sea of Okhotsk. They often breed in mixed-species colonies with Least Auklets, their smaller congener.The Crested Auklet can measure in length, in wingspan and weigh...
- 5,000,000 - 10,000,000 - Parakeet AukletParakeet AukletThe Parakeet Auklet is a small seabird of the North Pacific. It used to be placed on its own in the genus Cyclorrhynchus but recent morphological and genetic evidence suggest it should be placed in the genus Aethia. It is associated with the boreal waters of Alaska and Kamchatka and Siberia...
- 1,000,000 - 2,000,000
Breeding Season
Aethia auklets are endemic to the North Pacific OceanPacific Ocean
The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...
and Sea of Okhostk with notable Asia
Asia
Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...
n colonies in the Kuril Islands
Kuril Islands
The Kuril Islands , in Russia's Sakhalin Oblast region, form a volcanic archipelago that stretches approximately northeast from Hokkaidō, Japan, to Kamchatka, Russia, separating the Sea of Okhotsk from the North Pacific Ocean. There are 56 islands and many more minor rocks. It consists of Greater...
, Commander Islands, along the Kamchatka
Kamchatka Peninsula
The Kamchatka Peninsula is a peninsula in the Russian Far East, with an area of . It lies between the Pacific Ocean to the east and the Sea of Okhotsk to the west...
and Chukota Peninsulas
Chukchi Peninsula
The Chukchi Peninsula, Chukotka Peninsula or Chukotski Peninsula , at about 66° N 172° W, is the northeastern extremity of Asia. Its eastern end is at Cape Dezhnev near the village of Uelen. It is bordered by the Chukchi Sea to the north, the Bering Sea to the south, and the Bering Strait to the...
. In North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
, large colonies are in the Aleutian Islands (Buldir, Kiska
Kiska
Kiska is an island in the Rat Islands group of the Aleutian Islands of Alaska located at . It is about long and varies in width from - Discovery :...
, Semisopochnoi and Gareloi
Gareloi Island
Gareloi is a volcanic island in the Delarof Islands of the Aleutian Islands of Alaska. It is located between the Tanaga Pass and the Amchitka Pass....
) to the Gulf of Alaska
Gulf of Alaska
The Gulf of Alaska is an arm of the Pacific Ocean defined by the curve of the southern coast of Alaska, stretching from the Alaska Peninsula and Kodiak Island in the west to the Alexander Archipelago in the east, where Glacier Bay and the Inside Passage are found.The entire shoreline of the Gulf is...
and north to the islands of the Bering Sea
Bering Sea
The Bering Sea is a marginal sea of the Pacific Ocean. It comprises a deep water basin, which then rises through a narrow slope into the shallower water above the continental shelves....
(St. Lawrence Island
St. Lawrence Island
St. Lawrence Island is located west of mainland Alaska in the Bering Sea, just south of the Bering Strait, at about 63°30' North 173°20' West. The village of Gambell is located on the northwest cape, from the Chukchi Peninsula in the Russian Far East. The island is part of Alaska, but closer to...
, Pribilof Islands
Pribilof Islands
The Pribilof Islands are a group of four volcanic islands off the coast of mainland Alaska, in the Bering Sea, about north of Unalaska and 200 miles southwest of Cape Newenham. The Siberia coast is roughly northwest...
, St. Matthew Island
St. Matthew Island
St. Matthew Island is a remote island in the Bering Sea in Alaska, WNW of Nunivak Island. The island has a land area of , making it the 43rd largest island in the United States. Its most southerly point is Cape Upright which features cliff faces which exceed...
).
Auklets are have high site fidelity
Fidelity
"Fidelity" is the quality of being faithful or loyal. Its original meaning regarded duty to a lord or a king, in a broader sense than the related concept of fealty. Both derive from the Latin word fidēlis, meaning "faithful or loyal"....
, at both the colony and crevice level, although there can be a high divorce
Divorce
Divorce is the final termination of a marital union, canceling the legal duties and responsibilities of marriage and dissolving the bonds of matrimony between the parties...
rate of up to 33% in Least and Crested Auklets when both mates survive.
Winter Distribution
Winter distribution of auklets is poorly known. Whiskered Auklets likely winter near to breeding colonies and many were reported by Aleuts to winter in the general area. Auklets from the northern Bering Sea must move further south because of pack ice surrounding colonies during the winter.Breeding
Auklets are typically very social and nest in dense colonies (Parakeet AukletParakeet Auklet
The Parakeet Auklet is a small seabird of the North Pacific. It used to be placed on its own in the genus Cyclorrhynchus but recent morphological and genetic evidence suggest it should be placed in the genus Aethia. It is associated with the boreal waters of Alaska and Kamchatka and Siberia...
s are more dispersed). All have some form of facial ornamentation such as large crests (Whiskered
Whiskered Auklet
The Whiskered Auklet, Aethia pygmaea, is a small seabird of the auk family. It has a more restricted range than other members of its genus, Aethia, living only around the Aleutian Islands and on some islands off Siberia , and breeding on these islands. It is one of the smallest alcids, only the...
and Crested Auklet
Crested Auklet
The Crested Auklet is a small seabird of the family Alcidae which nests in huge colonies in the Bering Sea and Sea of Okhotsk. They often breed in mixed-species colonies with Least Auklets, their smaller congener.The Crested Auklet can measure in length, in wingspan and weigh...
s), auricular plumes (all four species), and Crested
Crested Auklet
The Crested Auklet is a small seabird of the family Alcidae which nests in huge colonies in the Bering Sea and Sea of Okhotsk. They often breed in mixed-species colonies with Least Auklets, their smaller congener.The Crested Auklet can measure in length, in wingspan and weigh...
and Whiskered Auklet
Whiskered Auklet
The Whiskered Auklet, Aethia pygmaea, is a small seabird of the auk family. It has a more restricted range than other members of its genus, Aethia, living only around the Aleutian Islands and on some islands off Siberia , and breeding on these islands. It is one of the smallest alcids, only the...
s have a tangerine-scented odour which may function in mate choice or species recognition, although this requires more study.
All Aethia auklets lay one white egg in a natural crevice and incubate for 25–36 days, after which, a semi-precocial chick emerges and fledge
Fledge
Fledge is the stage in a young bird's life when the feathers and wing muscles are sufficiently developed for flight. It also describes the act of a chick's parents raising it to a fully grown state...
s after 25–35 days. Age at first breeding is estimated at 3–5 years. Colony sizes
Group size measures
Many animals, including humans, tend to live in groups, herds, flocks, bands, packs, shoals, or colonies of conspecific individuals. The size of these groups, as expressed by the number of participant individuals, is an important aspect of their social environment...
are highly variable, and range from less than 100 individuals to over 1 million, although Least
Least Auklet
The Least Auklet, Aethia pusilla, is a seabird and the smallest species of auk. It is the most abundant seabird in North America, and one of the most abundant in the world, with a population of around nine million birds. They breed on the islands of Alaska and Siberia, and spend the winter close to...
and Crested Auklet
Crested Auklet
The Crested Auklet is a small seabird of the family Alcidae which nests in huge colonies in the Bering Sea and Sea of Okhotsk. They often breed in mixed-species colonies with Least Auklets, their smaller congener.The Crested Auklet can measure in length, in wingspan and weigh...
s tend to nest in greater density than Parakeet
Parakeet Auklet
The Parakeet Auklet is a small seabird of the North Pacific. It used to be placed on its own in the genus Cyclorrhynchus but recent morphological and genetic evidence suggest it should be placed in the genus Aethia. It is associated with the boreal waters of Alaska and Kamchatka and Siberia...
and Whiskered Auklet
Whiskered Auklet
The Whiskered Auklet, Aethia pygmaea, is a small seabird of the auk family. It has a more restricted range than other members of its genus, Aethia, living only around the Aleutian Islands and on some islands off Siberia , and breeding on these islands. It is one of the smallest alcids, only the...
s.
Diet
The auklets are mainly planktivores, eating a variety of calanoid copepodCopepod
Copepods are a group of small crustaceans found in the sea and nearly every freshwater habitat. Some species are planktonic , some are benthic , and some continental species may live in limno-terrestrial habitats and other wet terrestrial places, such as swamps, under leaf fall in wet forests,...
s, euphausiids
Krill
Krill is the common name given to the order Euphausiacea of shrimp-like marine crustaceans. Also known as euphausiids, these small invertebrates are found in all oceans of the world...
and other invertebrate
Invertebrate
An invertebrate is an animal without a backbone. The group includes 97% of all animal species – all animals except those in the chordate subphylum Vertebrata .Invertebrates form a paraphyletic group...
s such as jellyfish
Jellyfish
Jellyfish are free-swimming members of the phylum Cnidaria. Medusa is another word for jellyfish, and refers to any free-swimming jellyfish stages in the phylum Cnidaria...
and ctenophores. Winter diet has not been studied.
Threats and Conservation
Because they nest in crevices, auklets are vulnerable to predation by ratsRATS
RATS may refer to:* RATS , Regression Analysis of Time Series, a statistical package* Rough Auditing Tool for Security, a computer program...
, and have been extirpated from some islands that contained Arctic Fox
Arctic fox
The arctic fox , also known as the white fox, polar fox or snow fox, is a small fox native to Arctic regions of the Northern Hemisphere and is common throughout the Arctic tundra biome. The Greek word alopex, means a fox and Vulpes is the Latin version...
es introduced for farming. Eradication of rats from Rat Island
Rat Island (Alaska)
Rat Island is an island in the Rat Islands archipelago of the western Aleutian Islands in the U.S. state of Alaska. The island has a land area of 10.3126 sq mi and no permanent population...
was completed in 2008 and 2009.
The large colony at Sirius Point, Kiska Island
Kiska
Kiska is an island in the Rat Islands group of the Aleutian Islands of Alaska located at . It is about long and varies in width from - Discovery :...
, Alaska
Alaska
Alaska is the largest state in the United States by area. It is situated in the northwest extremity of the North American continent, with Canada to the east, the Arctic Ocean to the north, and the Pacific Ocean to the west and south, with Russia further west across the Bering Strait...
(perhaps the largest auklet colony in the world) experienced almost complete breeding failure in 2001 and 2002 because of rat predation and disturbance and has been the focus of researchers at Memorial University of Newfoundland
Memorial University of Newfoundland
Memorial University of Newfoundland, is a comprehensive university located primarily in St...
.http://www.mun.ca/serg/Kiska2002.html