The pelagic cormorant (''Urile pelagicus''), also known as Baird's cormorant or violet-green cormorant, is a small member of the
cormorant
Phalacrocoracidae is a family of approximately 40 species of aquatic birds commonly known as cormorants and shags. Several different classifications of the family have been proposed, but in 2021 the IOC adopted a consensus taxonomy of seven ge ...
family
Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...
Phalacrocoracidae. Analogous to other smallish cormorants, it is also called the pelagic shag occasionally. This
seabird
Seabirds (also known as marine birds) are birds that are adapted to life within the marine environment. While seabirds vary greatly in lifestyle, behaviour and physiology, they often exhibit striking convergent evolution, as the same envir ...
lives along the coasts of the northern
Pacific
The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the contine ...
; during winter it can also be found in the open
ocean
The ocean (also the sea or the world ocean) is the body of salt water that covers approximately 70.8% of the surface of Earth and contains 97% of Earth's water. An ocean can also refer to any of the large bodies of water into which the wor ...
.
[Orta (1992a)] Pelagic cormorants have relatively short wings due to their need for economical movement underwater, and consequently have the highest flight costs of any bird.
It was formerly classified in the genus ''
Phalacrocorax
''Phalacrocorax'' is a genus of fish-eating birds in the cormorant family Phalacrocoracidae. Members of this genus are also known as the Old World cormorants.
Taxonomy
The genus ''Phalacrocorax'' was introduced by the French zoologist Mathurin ...
'', but a 2014 study supported reclassifying it and several other Pacific cormorant species into the genus ''
Urile
''Urile'' is a genus of birds in the family Phalacrocoracidae, commonly known as North Pacific cormorants. It contains 3 extant and 1 recently extinct species, all of which are or were found in the North Pacific Ocean.
Members of this genus were ...
''.
The
IOC followed this classification in 2021.
Description
This is a smallish cormorant which measures in length, with a
wingspan
The wingspan (or just span) of a bird or an airplane is the distance from one wingtip to the other wingtip. For example, the Boeing 777–200 has a wingspan of , and a wandering albatross (''Diomedea exulans'') caught in 1965 had a wingspan o ...
of about and a weight of when fully grown. Adults in nonbreeding plumage are all-black with a metallic
iridescence
Iridescence (also known as goniochromism) is the phenomenon of certain surfaces that appear to gradually change color as the angle of view or the angle of illumination changes. Examples of iridescence include soap bubbles, feathers, butterfl ...
. In breeding plumage they grow two short crests (one on top of the head and one at the
nape), white
thigh
In human anatomy, the thigh is the area between the hip ( pelvis) and the knee. Anatomically, it is part of the lower limb.
The single bone in the thigh is called the femur. This bone is very thick and strong (due to the high proportion of ...
s, and scattered white
filoplume
Feathers are epidermal growths that form a distinctive outer covering, or plumage, on both avian (bird) and some non-avian dinosaurs and other archosaurs. They are the most complex integumentary structures found in vertebrates and a premier e ...
s on the head and neck. The long thin
bill
Bill(s) may refer to:
Common meanings
* Banknote, paper cash (especially in the United States)
* Bill (law), a proposed law put before a legislature
* Invoice, commercial document issued by a seller to a buyer
* Bill, a bird or animal's beak
Pla ...
and the large feet with
all-webbed toes are black throughout the year, while the patch of dark naked skin below the eye turns a vivid
magenta
Magenta () is a color that is variously defined as pinkish- purplish- red, reddish-purplish-pink or mauvish-crimson. On color wheels of the RGB (additive) and CMY (subtractive) color models, it is located exactly midway between red and blu ...
in the breeding season.
Males and females do not differ in appearance, though the latter is a bit smaller. Immature birds lack iridescence and are dark brown, grading into slightly lighter brown on the underside.
The widely
sympatric
In biology, two related species or populations are considered sympatric when they exist in the same geographic area and thus frequently encounter one another. An initially interbreeding population that splits into two or more distinct species s ...
red-faced cormorant
The red-faced cormorant (''Urile urile''), red-faced shag or violet shag, is a bird species of the family Phalacrocoracidae.
Its range spans from the eastern tip of Hokkaidō in Japan, northern korean peninsula, via the Kuril Islands, the sout ...
(''U. urile'') looks very similar. Breeding adults are easily told apart by the amount of naked facial skin, which does not noticeably extend beyond the eye in ''U. pelagicus'', but extends to above the bill and above and behind the eye in ''U. urile''; the latter species also has larger crests. Juveniles and nonbreeding adults of the two
species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriat ...
are often indistinguishable even to trained observers when in mixed flocks, or if they cannot be observed up close. In the former case, the large naked face "mask" and light bill of ''U. urile'' can be easily recognized, in the latter case its larger size (though male pelagic cormorants can be as large as female red-faced cormorants). Unlike the red-faced cormorant, the present species usually calls out before taking off, particularly during the breeding season. In
courtship display, nest material is typically torn and moved about (which ''U. urile'' might not do) and the males apparently do not bow their heads before the females as ''U. urile'' males do. Other North Pacific cormorants and shags are larger, with a thicker bill, and/or lack the white thighs in breeding plumage.
Range
The pelagic cormorant inhabits the shores and the
neritic zone of the
North Pacific
The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the continen ...
. Its
North America
North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and th ...
n range extends from
Alaska
Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U ...
to the
Baja California Peninsula in
Mexico
Mexico (Spanish language, Spanish: México), officially the United Mexican States, is a List of sovereign states, country in the southern portion of North America. It is borders of Mexico, bordered to the north by the United States; to the so ...
. It furthermore is found on the
Aleutian and other
Bering Strait islands, and from the
Russian Far East
The Russian Far East (russian: Дальний Восток России, r=Dal'niy Vostok Rossii, p=ˈdalʲnʲɪj vɐˈstok rɐˈsʲiɪ) is a region in Northeast Asia. It is the easternmost part of Russia and the Asian continent; and is admin ...
Chukchi Peninsula
The Chukchi Peninsula (also Chukotka Peninsula or Chukotski Peninsula; russian: Чуко́тский полуо́стров, ''Chukotskiy poluostrov'', short form russian: Чуко́тка, ''Chukotka''), at about 66° N 172° W, is the eastern ...
via
Sakhalin
Sakhalin ( rus, Сахали́н, r=Sakhalín, p=səxɐˈlʲin; ja, 樺太 ''Karafuto''; zh, c=, p=Kùyèdǎo, s=库页岛, t=庫頁島; Manchu: ᠰᠠᡥᠠᠯᡳᠶᠠᠨ, ''Sahaliyan''; Orok: Бугата на̄, ''Bugata nā''; Nivkh ...
south to
Kamchatka
The Kamchatka Peninsula (russian: полуостров Камчатка, Poluostrov Kamchatka, ) is a peninsula in the Russian Far East, with an area of about . The Pacific Ocean and the Sea of Okhotsk make up the peninsula's eastern and west ...
, and ultimately
Kyūshū
is the third-largest island of Japan's five main islands and the most southerly of the four largest islands ( i.e. excluding Okinawa). In the past, it has been known as , and . The historical regional name referred to Kyushu and its surround ...
(though not the rest of
Japan
Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the n ...
). The
subarctic
The subarctic zone is a region in the Northern Hemisphere immediately south of the true Arctic, north of humid continental regions and covering much of Alaska, Canada, Iceland, the north of Scandinavia, Siberia, and the Cairngorms. Genera ...
population
Population typically refers to the number of people in a single area, whether it be a city or town, region, country, continent, or the world. Governments typically quantify the size of the resident population within their jurisdiction usi ...
s are
migratory, while the birds from
temperate
In geography, the temperate climates of Earth occur in the middle latitudes (23.5° to 66.5° N/S of Equator), which span between the tropics and the polar regions of Earth. These zones generally have wider temperature ranges throughout ...
and
subtropical
The subtropical zones or subtropics are geographical and climate zones to the north and south of the tropics. Geographically part of the temperate zones of both hemispheres, they cover the middle latitudes from to approximately 35° north a ...
regions only disperse locally after breeding, but even so Asian birds may reach
China
China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's List of countries and dependencies by population, most populous country, with a Population of China, population exceeding 1.4 billion, slig ...
or
Korea
Korea ( ko, 한국, or , ) is a peninsular region in East Asia. Since 1945, it has been divided at or near the 38th parallel, with North Korea (Democratic People's Republic of Korea) comprising its northern half and South Korea (Republic ...
.
Vagrants have been recorded in the
Hawaiian Islands
The Hawaiian Islands ( haw, Nā Mokupuni o Hawai‘i) are an archipelago of eight major islands, several atolls, and numerous smaller islets in the North Pacific Ocean, extending some from the island of Hawaii in the south to northernmost ...
.
Ecology and biology
Diet
![Pelagic cormorants](https://upload.wikimedia.org/wikipedia/commons/0/0d/Pelagic_cormorants.jpg)
On land, pelagic cormorants are rather clumsy and walk with the high-stepped waddling gait typical for all
Sulae
The order Suliformes (, dubbed "Phalacrocoraciformes" by ''Christidis & Boles 2008'') is an order recognised by the International Ornithologist's Union. In regard to the recent evidence that the traditional Pelecaniformes is polyphyletic, it has ...
except
darter
The darters, anhingas, or snakebirds are mainly tropical waterbirds in the family Anhingidae, which contains a single genus, ''Anhinga''. There are four living species, three of which are very common and widespread while the fourth is rarer and ...
s; after landing they often scratch the ground, as is typical for cormorants. When they feel threatened, they will dart their bills at the intruder, and shake their heads and make a gargling noise. This bird forages by swimming to locate
prey
Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill ...
, then diving and going after it underwater, propelled by its feet and steering with the wings. It can dive as deep as to feed on or near the
seafloor. Typical hunting grounds are sheltered
inlet
An inlet is a (usually long and narrow) indentation of a shoreline, such as a small arm, bay, sound, fjord, lagoon or marsh, that leads to an enclosed larger body of water such as a lake, estuary, gulf or marginal sea.
Overview
In marine ...
s and
bay
A bay is a recessed, coastal body of water that directly connects to a larger main body of water, such as an ocean, a lake, or another bay. A large bay is usually called a gulf, sea, sound, or bight. A cove is a small, circular bay with a na ...
s; especially outside the breeding season they can also be seen fishing out at sea. They prefer to hunt in the vicinity of
kelp
Kelps are large brown algae seaweeds that make up the order Laminariales. There are about 30 different genera. Despite its appearance, kelp is not a plant - it is a heterokont, a completely unrelated group of organisms.
Kelp grows in "underwa ...
beds or among rocks. Typical prey are smallish, bottom-living non-
schooling fish
Fish are Aquatic animal, aquatic, craniate, gill-bearing animals that lack Limb (anatomy), limbs with Digit (anatomy), digits. Included in this definition are the living hagfish, lampreys, and Chondrichthyes, cartilaginous and bony fish as we ...
es, such as ''
Ammodytes
''Ammodytes'' is a genus of sand lances native to the northern oceans.
Species
There are currently 8 recognized species in this genus:
* ''Ammodytes americanus'' DeKay, 1842 (American sand lance)
* ''Ammodytes dubius'' J. C. H. Reinhardt, 18 ...
''
sand eels,
sculpin
A sculpin is a type of fish that belongs to the superfamily Cottoidea in the order Scorpaeniformes.Kane, E. A. and T. E. Higham. (2012)Life in the flow lane: differences in pectoral fin morphology suggest transitions in station-holding demand ...
s (Cottidae),
gunnels (Pholidae) and ''
Sebastes
''Sebastes'' is a genus of marine ray-finned fish belonging to the subfamily Sebastinae part of the family Scorpaenidae, most of which have the common name of rockfish. A few are called ocean perch, sea perch or redfish instead. They are found ...
'' (
rockfish). Apart from fish, small
crustacean
Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapoda, decapods, ostracoda, seed shrimp, branchiopoda, branchiopods, argulidae, fish lice, krill, remipedes, isopoda, isopods, barnacles, copepods, ...
s – in particular
shrimp
Shrimp are crustaceans (a form of shellfish) with elongated bodies and a primarily swimming mode of locomotion – most commonly Caridea and Dendrobranchiata of the decapod order, although some crustaceans outside of this order are ref ...
– are also often eaten. It has been observed to join
mixed-species feeding flock
A mixed-species feeding flock, also termed a mixed-species foraging flock, mixed hunting party or informally bird wave, is a flock of usually insectivorous birds of different species that join each other and move together while foraging. These are ...
s going after schools of young
Pacific herrings (''Clupea pallasii''). Like all cormorants, due to their vestigial
uropygial gland
The uropygial gland, informally known as the preen gland or the oil gland, is a bilobed sebaceous gland possessed by the majority of birds used to distribute the gland's oil through the plumage by means of preening. It is located dorsally at th ...
their plumage is not
waterproof. Thus, the birds return to a safe place after foraging to
preen and dry their feathers, typically adopting a spread-winged posture.
Breeding
![Phalacrocorax pelagicus -San Luis Obispo, California, USA -nest-8 (3)](https://upload.wikimedia.org/wikipedia/commons/e/e9/Phalacrocorax_pelagicus_-San_Luis_Obispo%2C_California%2C_USA_-nest-8_%283%29.jpg)
The pelagic cormorant breeds on
rocky shores and islands. They do not form large
colonies
In modern parlance, a colony is a territory subject to a form of foreign rule. Though dominated by the foreign colonizers, colonies remain separate from the administration of the original country of the colonizers, the '' metropolitan state'' ...
, but smaller groups may nest together. In some cases these birds alternate between two or three nesting sites in a region from one year to another. The nest is built at the cliff face, usually on ledges, less often in crevices or caves. The nest is built from stringy
plant
Plants are predominantly photosynthetic eukaryotes of the kingdom Plantae. Historically, the plant kingdom encompassed all living things that were not animals, and included algae and fungi; however, all current definitions of Plantae excl ...
s, such as
grass
Poaceae () or Gramineae () is a large and nearly ubiquitous family of monocotyledonous flowering plants commonly known as grasses. It includes the cereal grasses, bamboos and the grasses of natural grassland and species cultivated in lawns a ...
es or
seaweed
Seaweed, or macroalgae, refers to thousands of species of macroscopic, multicellular, marine algae. The term includes some types of '' Rhodophyta'' (red), ''Phaeophyta'' (brown) and '' Chlorophyta'' (green) macroalgae. Seaweed species such as ...
, and held together by the birds' own
guano
Guano (Spanish from qu, wanu) is the accumulated excrement of seabirds or bats. As a manure, guano is a highly effective fertilizer due to the high content of nitrogen, phosphate, and potassium, all key nutrients essential for plant growth. G ...
. Once the birds have found a nest site they like, they tend to remain faithful to it for the rest of their lives. The nest is repaired and improved in each season if need be; it can thus grow up to deep.
Males searching for a mate or bonding with their partner give an elaborate
courtship display, as is typical for Sulae. Like all cormorants, this includes stretching the
gular sac with the
hyoid bone
The hyoid bone (lingual bone or tongue-bone) () is a horseshoe-shaped bone situated in the anterior midline of the neck between the chin and the thyroid cartilage. At rest, it lies between the base of the mandible and the third cervical verteb ...
and repeated "yawning"; as in many but not all cormorants, the pelagic cormorant's display furthermore includes arching the neck and hopping, lifting the folded wings and rapidly fluttering them to show the white thigh patches. During the yawning display, the head is thrown back and calls are given which differ between males and females; when the birds land, males and females give an identical call. Otherwise, the displays are given in silence.
The
clutch
A clutch is a mechanical device that engages and disengages power transmission, especially from a drive shaft to a driven shaft. In the simplest application, clutches connect and disconnect two rotating shafts (drive shafts or line shafts). ...
is generally between two and five
eggs, most often three or four, but clutches of up to seven eggs have been recorded.
Incubation lasts for 3 weeks to one month. At hatching, the young weigh somewhat more than an ounce (35 g) and are naked, but they soon grow
soot
Soot ( ) is a mass of impure carbon particles resulting from the incomplete combustion of hydrocarbons. It is more properly restricted to the product of the gas-phase combustion process but is commonly extended to include the residual pyrolysed ...
y-gray
down feather
The down of birds is a layer of fine feathers found under the tougher exterior feathers. Very young birds are clad only in down. Powder down is a specialized type of down found only in a few groups of birds. Down is a fine thermal insulator an ...
s. In normal years, all young of a typical clutch may be raised successfully, but less than four rarely
fledge
Fledging is the stage in a flying animal's life between hatching or birth and becoming capable of flight.
This term is most frequently applied to birds, but is also used for bats. For altricial birds, those that spend more time in vulnerable c ...
. On the other hand, during unfavorable phases of the
Pacific decadal oscillation
The Pacific decadal oscillation (PDO) is a robust, recurring pattern of ocean-atmosphere climate variability centered over the mid-latitude Pacific basin. The PDO is detected as warm or cool surface waters in the Pacific Ocean, north of 20°N. O ...
, most pairs manage to raise only two young at most. They reach
sexual maturity
Sexual maturity is the capability of an organism to reproduce. In humans it might be considered synonymous with adulthood, but here puberty is the name for the process of biological sexual maturation, while adulthood is based on cultural definitio ...
at two years of age, and a maximum age of almost eighteen years has been recorded in the wild.
Status
This numerous and widespread species is not considered threatened by the
IUCN
The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...
. The bulk of its population is found in the relatively inaccessible waters of the Bering Sea region; about 50,000 each breed in the Kuril Islands, the Bering Sea islands, and the U.S. state of Alaska and its offshore islands (including the Aleuts). About 25,000 breed down the Pacific coast of North America, some 60% of which are found in California. Local populations may be all but wiped out temporarily by
oil spill
An oil spill is the release of a liquid petroleum hydrocarbon into the environment, especially the marine ecosystem, due to human activity, and is a form of pollution. The term is usually given to marine oil spills, where oil is released into th ...
s, and on a larger scale competition with
gillnet fisheries and drowning in such nets is putting a limit to its stocks.
The
acanthocephala
Acanthocephala (Greek , ', thorn + , ', head) is a phylum of parasitic worms known as acanthocephalans, thorny-headed worms, or spiny-headed worms, characterized by the presence of an eversible proboscis, armed with spines, which it uses to p ...
n parasite ''
Andracantha phalacrocoracis'' was described from this cormorant.
Taxonomy and systematics
The cormorant
family
Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...
Phalacrocoracidae has traditionally been included – like all other
bird
Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweigh ...
s with fully webbed toes – in the
Pelecaniformes
The Pelecaniformes are an order of medium-sized and large waterbirds found worldwide. As traditionally—but erroneously—defined, they encompass all birds that have feet with all four toes webbed. Hence, they were formerly also known by such ...
. But the namesake
pelican
Pelicans (genus ''Pelecanus'') are a genus of large water birds that make up the family Pelecanidae. They are characterized by a long beak and a large throat pouch used for catching prey and draining water from the scooped-up contents before s ...
s (Pelecanidae) are actually closer relatives of
stork
Storks are large, long-legged, long-necked wading birds with long, stout bills. They belong to the family called Ciconiidae, and make up the order Ciconiiformes . Ciconiiformes previously included a number of other families, such as herons an ...
s (Ciconiidae) than of cormorants. Hence, it has been proposed to separate the Phalacrocoracidae and relatives as
order Phalacrocoraciformes
The order Suliformes (, dubbed "Phalacrocoraciformes" by ''Christidis & Boles 2008'') is an order recognised by the International Ornithologist's Union. In regard to the recent evidence that the traditional Pelecaniformes is polyphyletic, it has ...
. More recent evidence indicates that they and the
darter
The darters, anhingas, or snakebirds are mainly tropical waterbirds in the family Anhingidae, which contains a single genus, ''Anhinga''. There are four living species, three of which are very common and widespread while the fourth is rarer and ...
s actually belong in the order
Suliformes
The order Suliformes (, dubbed "Phalacrocoraciformes" by ''Christidis & Boles 2008'') is an order recognised by the International Ornithological Congress, International Ornithologist's Union. In regard to the recent evidence that the traditional ...
, alongside the
boobies
A booby is a seabird in the genus ''Sula'', part of the family Sulidae. Boobies are closely related to the gannets (''Morus''), which were formerly included in ''Sula''.
Systematics and evolution
The genus ''Sula'' was introduced by the Fren ...
and
gannet
Gannets are seabirds comprising the genus ''Morus'' in the family Sulidae, closely related to boobies.
Gannets are large white birds with yellowish heads; black-tipped wings; and long bills. Northern gannets are the largest seabirds in the ...
s.
![Red-faced Cormorant](https://upload.wikimedia.org/wikipedia/commons/a/aa/Red-faced_Cormorant.jpg)
This
species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriat ...
was formerly placed in the catch-all
genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...
''
Phalacrocorax
''Phalacrocorax'' is a genus of fish-eating birds in the cormorant family Phalacrocoracidae. Members of this genus are also known as the Old World cormorants.
Taxonomy
The genus ''Phalacrocorax'' was introduced by the French zoologist Mathurin ...
''. Modern authors were previously reserved about uniting all cormorants in one "
wastebin genus
Wastebasket taxon (also called a wastebin taxon, dustbin taxon or catch-all taxon) is a term used by some taxonomists to refer to a taxon that has the sole purpose of classifying organisms that do not fit anywhere else. They are typically define ...
", but most revisions published had on
phylogenetic
In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups o ...
merit. Though it was proposed to place the pelagic cormorant in ''Stictocarbo'' for example, this is quite certainly wrong, as the present species is by no means closely related to the
spotted shag
The spotted shag or pārekareka (''Phalacrocorax punctatus'') is a species of cormorant endemic to New Zealand. Though originally classified as ''Phalacrocorax punctatus'', it is sufficiently different in appearance from typical members of that ...
(''P. punctatus''), the
type species
In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen ...
of ''Stictocarbo''. Similarly, ''Leucocarbo'' would refer to the group around the
imperial shag
The imperial shag or imperial cormorant (''Leucocarbo atriceps'') is a black and white cormorant native to southern South America, primarily in rocky coastal regions, but locally also at large inland lakes. Some taxonomic authorities, including ...
(''P. atriceps'') complex, which occurs on the opposite end of the Earth from ''P. pelagicus''. The supposed "cliff shag"
subfamily
In biological classification, a subfamily (Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family but more inclusive than genus. Standard nomenclature rules end subfamily botanical names with "-oideae", and zoologi ...
Leucocarboninae is entirely
paraphyletic
In taxonomy (general), taxonomy, a group is paraphyletic if it consists of the group's most recent common ancestor, last common ancestor and most of its descendants, excluding a few Monophyly, monophyletic subgroups. The group is said to be pa ...
cannot be accepted as originally circumscribed. If subfamilies are to be accepted in the Phalacrocoracidae, the pelagic shag and its relatives would go in the Phalacrocoracinae like most
Northern Hemisphere
The Northern Hemisphere is the half of Earth that is north of the Equator. For other planets in the Solar System, north is defined as being in the same celestial hemisphere relative to the invariable plane of the solar system as Earth's Nort ...
cormorants and shags, while Leucocarboninae would include mainly
Southern Hemisphere taxa
In biology, a taxon (back-formation from ''taxonomy''; plural taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular nam ...
.
Another theory held that the
genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...
name for the pelagic cormorant, if ''Phalacrocorax'' was to be split up, would be ''Compsohalieus''. This name would apply to the group around its
type species
In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen ...
(
Brandt's cormorant, ''P. penicillatus''). This is a
North Pacific
The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the continen ...
clade
A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, ...
, which apart from Brandt's and the pelagic cormorant also includes the
red-faced cormorant
The red-faced cormorant (''Urile urile''), red-faced shag or violet shag, is a bird species of the family Phalacrocoracidae.
Its range spans from the eastern tip of Hokkaidō in Japan, northern korean peninsula, via the Kuril Islands, the sout ...
(''P. urile'') and probably also the
extinct
Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...
spectacled cormorant (''P. perspicillatus''). They all have black feet, and in breeding plumage grow white
filoplume
Feathers are epidermal growths that form a distinctive outer covering, or plumage, on both avian (bird) and some non-avian dinosaurs and other archosaurs. They are the most complex integumentary structures found in vertebrates and a premier e ...
s on the head and/or neck, and usually also two head-crests and white
thigh
In human anatomy, the thigh is the area between the hip ( pelvis) and the knee. Anatomically, it is part of the lower limb.
The single bone in the thigh is called the femur. This bone is very thick and strong (due to the high proportion of ...
patches like the present species does. They also share the back-thrown head during the "yawning" and the rapid wing-flutter in
courtship display. Among the ''Compsohalieus'' group, the red-faced cormorant is the
sister species
In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree.
Definition
The expression is most easily illustrated by a cladogram:
Taxon A and t ...
of ''P. pelagicus''. Apart from looking almost alike, these two species also "yawn" many times in a row instead of giving the display just once, twist their bodies before taking flight during courtship, and the male and female post-landing calls are identical. The point-and-gargle response to threats is also an
apomorph
In phylogenetics, an apomorphy (or derived trait) is a novel character or character state that has evolved from its ancestral form (or plesiomorphy). A synapomorphy is an apomorphy shared by two or more taxa and is therefore hypothesized to have ...
y of these two species. In 2014, a study was published supporting this treatment, albeit classifying the species in the genus ''
Urile
''Urile'' is a genus of birds in the family Phalacrocoracidae, commonly known as North Pacific cormorants. It contains 3 extant and 1 recently extinct species, all of which are or were found in the North Pacific Ocean.
Members of this genus were ...
'' rather than ''Compsohalieus''. The
IUCN
The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...
,
BirdLife International
BirdLife International is a global partnership of non-governmental organizations that strives to conserve birds and their habitats. BirdLife International's priorities include preventing extinction of bird species, identifying and safeguarding ...
, and the
IOC have since followed this classification, legitimizing it.
Its former
scientific name
In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bot ...
was the literal
Latin
Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...
ized
Ancient Greek
Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic peri ...
equivalent of the common name: ''Phalacrocorax'' is an ancient term for cormorants; literally, it means "bald
raven
A raven is any of several larger-bodied bird species of the genus ''Corvus''. These species do not form a single taxonomic group within the genus. There is no consistent distinction between "crows" and "ravens", common names which are assigned t ...
", from ''falakrós'' (φᾶλακρός, "bald") + ''kórax'' (κόραξ, "raven"). ''Pelagicus'' is – like the English (language), English loanword "pelagic" – derived from (πελᾶγιος, "of the open seas"). ''Compsohalieus'', meanwhile, means "sleek fisher"; it derives from (κομψός, "elegant" or "sleek") + ' (ἇλιεύς, "fisherman"). ''Urile'' is a term coined by Charles Lucien Bonaparte, Bonaparte in 1855 as the species name for the red-faced cormorant.
Subspecies
Two subspecies are generally recognized. The difference between them is slight and generally agrees with Bergmann's Rule:
* ''Urile pelagicus pelagicus''
Peter Simon Pallas, Pallas, 1811 – Northern pelagic cormorant. northwest
Pacific
The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the contine ...
east to south
Alaska
Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U ...
. The larger subspecies (but see below).
* ''Urile pelagicus resplendens''
John James Audubon, Audubon, 1838 – Southern pelagic cormorant. British Columbia to northwest
Mexico
Mexico (Spanish language, Spanish: México), officially the United Mexican States, is a List of sovereign states, country in the southern portion of North America. It is borders of Mexico, bordered to the north by the United States; to the so ...
. The smaller subspecies.
The Amchitka cormorant or Kenyon's shag (''U. kenyoni'') is a supposed
species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriat ...
that was presumed to be closely related to the pelagic cormorant. It was described from the bones of three individuals snared in fishing nets in the late 1950s at Constantine Harbor on Amchitka Island, Amchitka in the Aleutian Islands. The specific name (zoology), specific name ''kenyoni'' honors USFWS biologist Karl W. Kenyon, who collected the type specimen USNM 431164 on 22 February 1959. Some bones from prehistoric middens on Amchitka were also attributed to this taxon. As distinctive cormorants were never seen alive in recent years on Amchitka, it was conjectured by some that Kenyon's shag might have gone
extinct
Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...
in the 1960s–1970s (marine pollution and overfishing would be possible reasons).
However, a subsequent analysis of a larger number of comparison specimens of the pelagic cormorant – mainly from birds that fell victim to the Exxon Valdez oil spill, ''Exxon Valdez'' oil spill – determined that the bones were attributable to small females of the latter species, and that their apparent distinctness was due to the original canonical analysis being distorted by insufficient specimens. The researchers also found that contrary to what was generally assumed, pelagic cormorants from the Aleutians were generally small birds – as opposed to western Alaskan individuals, which are usually very large. If the Aleutian population were to be considered a distinct subspecies, the name ''kenyoni'' would apply. Verification of subspecies status would require DNA sequence analyses however, since the differences in Morphology (biology), morphology are not large and there is much variation between individuals.
In 2003, during an USFWS survey three small pelagic cormorants whose bills appeared to be red were noted at Karab Cove on Agattu Island. It may be that these were ''kenyoni'', but whether the bill color distinguishes the presumed subspecies or whether it is due to a simple mutation has not been determined. The large birds from the Prince William Sound region were formerly called ''U. p. robustus'', but are not considered distinct today. Since there appear to be at least two recognizable and allopatric size groups in the northern subspecies alone, more research is clearly necessary.
[Hobson (1997), Rohwer ''et al.'' (2000), Byrd & Williams (2004)]
Footnotes
References
* AnAge [2009]
''Phalacrocorax pelagicus'' life history data Retrieved 2009-SEP-12.
* Byrd, G.V. & Williams, J.C. (2004): Cormorant surveys in the Near Island Group, Aleutian Islands, Alaska in July 2003 with notes on other species. ''U.S. Fish and Wildlife Service Reports ANMWR'' 03/13.
* Leslie Christidis, Christidis, Les & Boles, Walter E. (2008)
''Systematics and Taxonomy of Australian Birds'' CSIRO Publishing, Collingwood, Victoria, Australia.
* Fuller, Errol (2000): ''Extinct Birds'' (2nd ed.). Oxford University Press, Oxford, New York.
* Hobson, K.A. (1997): Pelagic Cormorant (''Phalacrocorax pelagicus''). ''In:'' Poole, A. & Gill, F. (eds.): ''The Birds of North America'' 282. The Academy of Natural Sciences, Philadelphia, PA & The American Ornithologists' Union, Washington, D.C.
* Erratum:
*
*
* Orta, Jaume (1992a): 12. Pelagic Cormorant. ''In:'' del Hoyo, Josep; Elliott, Andrew & Sargatal, Jordi (eds.): ''Handbook of Birds of the World'' (Volume 1: Ostrich to Ducks): 346, plate 22. Lynx Edicions, Barcelona.
* Orta, Jaume (1992b): Family Phalacrocoracidae (Cormorants). ''In:'' del Hoyo, Josep; Elliott, Andrew & Sargatal, Jordi (eds.): ''Handbook of Birds of the World'' (Volume 1: Ostrich to Ducks): 326–353, plates 22–23. Lynx Edicions, Barcelona.
*
SORA link*
*
*
* Woodhouse, S.C. (1910)
''English-Greek Dictionary – A Vocabulary of the Attic Language'' George Routledge & Sons Ltd., Broadway House, Ludgate Hill, E.C.
{{Authority control
Urile, pelagic cormorant
Cormorants, pelagic cormorant
Native birds of Alaska
Birds of the Aleutian Islands
Birds of North Asia
Native birds of Western Canada
Native birds of the West Coast of the United States
Birds described in 1811, pelagic cormorant
Taxa named by Peter Simon Pallas