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 recently, and the number of genera is disputed. The great cormorant (P. carbo) and the common shag (P. aristotelis) are the only two species of the family commonly encountered on the British Isles, and "cormorant" and "shag" appellations have been later assigned to different species in the family somewhat haphazardly.
Cormorants and shags are medium-to-large birds, with body weight in the range of 0.35–5 kilograms (0.77–11.02 lb) and wing span of 45–100 centimetres (18–39 in). The majority of species have dark feathers. The bill is long, thin and hooked. Their feet have webbing between all four toes. All species are fish-eaters, catching the prey by diving from the surface. They are excellent divers, and under water they propel themselves with their feet with help from their wings; some cormorant species have been found to dive as deep as 45 metres (150 ft). They have relatively short wings due to their need for economical movement underwater, and consequently have the highest flight costs of any flying bird.
Cormorants nest in colonies around the shore, on trees, islets or cliffs. They are coastal rather than oceanic birds, and some have colonised inland waters – indeed, the original ancestor of cormorants seems to have been a fresh-water bird. They range around the world, except for the central Pacific islands.
|Cormorants and shags|
Temporal range: Late Cretaceous – Recent
|Little pied cormorant|
Australocorax Lambrecht, 1931
No consistent distinction exists between cormorants and shags. The names 'cormorant' and 'shag' were originally the common names of the two species of the family found in Great Britain, Phalacrocorax carbo (now referred to by ornithologists as the great cormorant) and P. aristotelis (the European shag). "Shag" refers to the bird's crest, which the British forms of the great cormorant lack. As other species were discovered by English-speaking sailors and explorers elsewhere in the world, some were called cormorants and some shags, depending on whether they had crests or not. Sometimes the same species is called a cormorant in one part of the world and a shag in another, e.g., the great cormorant is called the black shag in New Zealand (the birds found in Australasia have a crest that is absent in European members of the species). Van Tets (1976) proposed to divide the family into two genera and attach the name "cormorant" to one and "shag" to the other, but this flies in the face of common usage and has not been widely adopted.
The scientific genus name is Latinised Ancient Greek, from φαλακρός (phalakros, "bald") and κόραξ (korax, "raven"). This is often thought to refer to the creamy white patch on the cheeks of adult great cormorants, or the ornamental white head plumes prominent in Mediterranean birds of this species, but is certainly not a unifying characteristic of cormorants. "Cormorant" is a contraction derived either directly from Latin corvus marinus, "sea raven" or through Brythonic Celtic. Cormoran is the Cornish name of the sea giant in the tale of Jack the Giant Killer. Indeed, "sea raven" or analogous terms were the usual terms for cormorants in Germanic languages until after the Middle Ages. The French explorer André Thévet commented in 1558, "... the beak [is] similar to that of a cormorant or other corvid," which demonstrates that the erroneous belief that the birds were related to ravens lasted at least to the 16th century.
Cormorants and shags are medium-to-large seabirds. They range in size from the pygmy cormorant (Phalacrocorax pygmaeus), at as little as 45 cm (18 in) and 340 g (12 oz), to the flightless cormorant (Phalacrocorax harrisi), at a maximum size 100 cm (39 in) and 5 kg (11 lb). The recently extinct spectacled cormorant (Phalacrocorax perspicillatus) was rather larger, at an average size of 6.3 kg (14 lb). The majority, including nearly all Northern Hemisphere species, have mainly dark plumage, but some Southern Hemisphere species are black and white, and a few (e.g. the spotted shag of New Zealand) are quite colourful. Many species have areas of coloured skin on the face (the lores and the gular skin) which can be bright blue, orange, red or yellow, typically becoming more brightly coloured in the breeding season. The bill is long, thin, and sharply hooked. Their feet have webbing between all four toes, as in their relatives.
They are coastal rather than oceanic birds, and some have colonised inland waters – indeed, the original ancestor of cormorants seems to have been a fresh-water bird, judging from the habitat of the most ancient lineage. They range around the world, except for the central Pacific islands.
All are fish-eaters, dining on small eels, fish, and even water snakes. They dive from the surface, though many species make a characteristic half-jump as they dive, presumably to give themselves a more streamlined entry into the water. Under water they propel themselves with their feet, though some also propel themselves with their wings (see the picture, commentary, and existing reference video). Some cormorant species have been found, using depth gauges, to dive to depths of as much as 45 metres (150 ft).
After fishing, cormorants go ashore, and are frequently seen holding their wings out in the sun. All cormorants have preen gland secretions that are used ostensibly to keep the feathers waterproof. Some sources state that cormorants have waterproof feathers while others say that they have water permeable feathers. Still others suggest that the outer plumage absorbs water but does not permit it to penetrate the layer of air next to the skin. The wing drying action is seen even in the flightless cormorant but commonly in the Antarctic shags and red-legged cormorants. Alternate functions suggested for the spread-wing posture include that it aids thermoregulation or digestion, balances the bird, or indicates presence of fish. A detailed study of the great cormorant concludes that it is without doubt to dry the plumage.
Cormorants are colonial nesters, using trees, rocky islets, or cliffs. The eggs are a chalky-blue colour. There is usually one brood a year. The young are fed through regurgitation. They typically have deep, ungainly bills, showing a greater resemblance to those of the pelicans, to which they are related, than is obvious in the adults.
The cormorants are a group traditionally placed within the Pelecaniformes or, in the Sibley–Ahlquist taxonomy, the expanded Ciconiiformes. This latter group is certainly not a natural one, and even after the tropicbirds have been recognised as quite distinct, the remaining Pelecaniformes seem not to be entirely monophyletic. Their relationships and delimitation – apart from being part of a "higher waterfowl" clade which is similar but not identical to Sibley and Ahlquist's "pan-Ciconiiformes" – remain mostly unresolved. Notwithstanding, all evidence agrees that the cormorants and shags are closer to the darters and Sulidae (gannets and boobies), and perhaps the pelicans or even penguins, than to all other living birds.
In recent years, three preferred treatments of the cormorant family have emerged: either to leave all living cormorants in a single genus, Phalacrocorax, or to split off a few species such as the imperial shag complex (in Leucocarbo) and perhaps the flightless cormorant. Alternatively, the genus may be disassembled altogether and in the most extreme case be reduced to the great, white-breasted and Japanese cormorants.
Pending a thorough review of the Recent and prehistoric cormorants, the single-genus approach is followed here for three reasons: first, it is preferable to tentatively assigning genera without a robust hypothesis. Second, it makes it easier to deal with the fossil forms, the systematic treatment of which has been no less controversial than that of living cormorants and shags. Third, this scheme is also used by the IUCN, making it easier to incorporate data on status and conservation. In accordance with the treatment there, the imperial shag complex is here left unsplit as well, but the king shag complex has been.
The cormorants and the darters have a unique bone on the back of the top of the skull known as the os nuchale or occipital style which was called a xiphoid process in early literature. This bony projection provides anchorage for the muscles that increase the force with which the lower mandible is closed. This bone and the highly developed muscles over it, the M. adductor mandibulae caput nuchale, are unique to the families Phalacrocoracidae and Anhingidae.
Several evolutionary groups are still recognizable. However, combining the available evidence suggests that there has also been a great deal of convergent evolution; for example the cliff shags are a convergent paraphyletic group. The proposed division into Phalacrocorax sensu stricto (or subfamily "Phalacrocoracinae") cormorants and Leucocarbo sensu lato (or "Leucocarboninae") shags does indeed have some degree of merit. The resolution provided by the mtDNA 12S rRNA and ATPase subunits six and eight sequence data is not sufficient to properly resolve several groups to satisfaction; in addition, many species remain unsampled, the fossil record has not been integrated in the data, and the effects of hybridisation – known in some Pacific species especially – on the DNA sequence data are unstudied.
The family contains three genera:
Cormorants seem to be a very ancient group, with similar ancestors reaching back to the time of the dinosaurs. In fact, the earliest known modern bird, Gansus yumenensis, had essentially the same structure. The details of the evolution of the cormorant are mostly unknown. Even the technique of using the distribution and relationships of a species to figure out where it came from, biogeography, usually very informative, does not give very specific data for this probably rather ancient and widespread group. However, the closest living relatives of the cormorants and shags are the other families of the suborder Sulae—darters and gannets and boobies—which have a primarily Gondwanan distribution. Hence, at least the modern diversity of Sulae probably originated in the southern hemisphere.
While the Leucocarbonines are almost certainly of southern Pacific origin—possibly even the Antarctic which, at the time when cormorants evolved, was not yet ice-covered—all that can be said about the Phalacrocoracines is that they are most diverse in the regions bordering the Indian Ocean, but generally occur over a large area.
Similarly, the origin of the family is shrouded in uncertainties. Some Late Cretaceous fossils have been proposed to belong with the Phalacrocoracidae:
A scapula from the Campanian-Maastrichtian boundary, about 70 mya (million years ago), was found in the Nemegt Formation in Mongolia; it is now in the PIN collection. It is from a bird roughly the size of a spectacled cormorant, and quite similar to the corresponding bone in Phalacrocorax. A Maastrichtian (Late Cretaceous, c. 66 mya) right femur, AMNH FR 25272 from the Lance Formation near Lance Creek, Wyoming, is sometimes suggested to be the second-oldest record of the Phalacrocoracidae; this was from a rather smaller bird, about the size of a long-tailed cormorant.
As the Early Oligocene Sula" ronzoni cannot be assigned to any of the suloid families—cormorants and shags, darters, and gannets and boobies—with certainty, the best interpretation is that the Phalacrocoracidae diverged from their closest ancestors in the Early Oligocene, perhaps some 30 million years ago, and that the Cretaceous fossils represent ancestral suloids, "pelecaniforms" or "higher waterbirds"; at least the last lineage is generally believed to have been already distinct and undergoing evolutionary radiation at the end of the Cretaceous. What can be said with near certainty is that AMNH FR 25272 is from a diving bird that used its feet for underwater locomotion; as this is liable to result in some degree of convergent evolution and the bone is missing indisputable neornithine features, it is not entirely certain that the bone is correctly referred to this group.
During the late Paleogene, when the family presumably originated, much of Eurasia was covered by shallow seas, as the Indian Plate finally attached to the mainland. Lacking a detailed study, it may well be that the first "modern" cormorants were small species from eastern, south-eastern or southern Asia, possibly living in freshwater habitat, that dispersed due to tectonic events. Such a scenario would account for the present-day distribution of cormorants and shags and is not contradicted by the fossil record; as remarked above, a thorough review of the problem is not yet available.
Two distinct genera of prehistoric cormorants are widely accepted today, if Phalacrocorax is used for all living species:
The proposed genus Oligocorax appears to be paraphyletic – the European species have been separated in Nectornis, and the North American ones are placed in the expanded Phalacrocorax. A Late Oligocene fossil cormorant foot from Enspel, Germany, sometimes placed herein, would then be referable to Nectornis if it proves not to be too distinct. All these early European species might belong to the basal group of "microcormorants", as they conform with them in size and seem to have inhabited the same habitat: subtropical coastal or inland waters. Limicorallus, meanwhile, was initially believed to be a rail or a dabbling duck by some. There are also undescribed remains of apparent cormorants from the Quercy Phosphorites of Quercy (France), dating to some time between the Late Eocene and the mid-Oligocene.
Some other Paleogene remains are sometimes assigned to the Phalacrocoracidae, but these birds seem quite intermediate between cormorants and darters (and lack clear autapomorphies of either). Thus, they may be quite basal members of the Palacrocoracoidea. The taxa in question are:
The remaining species are, in accordance with the scheme used in this article, all placed in the modern genus Phalacrocorax:
Humans have used cormorants' fishing skills in various places in the world. Archaeological evidence suggests that cormorant fishing was practiced in Ancient Egypt, Peru, Korea and India, but the strongest tradition has remained in China and Japan, where it reached commercial-scale level in some areas. In Japan, cormorant fishing is called ukai (鵜飼). Traditional forms of ukai can be seen on the Nagara River in the city of Gifu, Gifu Prefecture, where cormorant fishing has continued uninterrupted for 1300 years, or in the city of Inuyama, Aichi. In Guilin, China, cormorants are famous for fishing on the shallow Lijiang River. In Gifu, the Japanese cormorant (P. capillatus) is used; Chinese fishermen often employ great cormorants (P. carbo). In Europe, a similar practice was also used on Doiran Lake in the region of Macedonia.
In a common technique, a snare is tied near the base of the bird's throat, which allows the bird only to swallow small fish. When the bird captures and tries to swallow a large fish, the fish is caught in the bird's throat. When the bird returns to the fisherman's raft, the fisherman helps the bird to remove the fish from its throat. The method is not as common today, since more efficient methods of catching fish have been developed, but is still practiced as a cultural tradition.
Cormorants feature in heraldry and medieval ornamentation, usually in their "wing-drying" pose, which was seen as representing the Christian cross, and symbolizing nobility and sacrifice. For John Milton in Paradise Lost, the cormorant symbolizes greed: perched atop the Tree of Life, Satan took the form of a cormorant as he spied on Adam and Eve during his first intrusion into Eden.
In some Scandinavian areas, they are considered good omen; in particular, in Norwegian tradition spirits of those lost at sea come to visit their loved ones disguised as cormorants. For example, the Norwegian municipalities of Røst, Loppa and Skjervøy have cormorants in their coat of arms. The symbolic liver bird of Liverpool is commonly thought to be a cross between an eagle and a cormorant.
In 1853, a woman wearing a dress made of cormorant feathers was found on San Nicolas Island, off the southern coast of California. She had sewn the feather dress together using whale sinews. She is known as the Lone Woman of San Nicolas and was later baptised "Juana Maria" (her original name is lost). The woman had lived alone on the island for 18 years before being rescued. When removed from San Nicolas, she brought with her a green cormorant dress she made; this dress is reported to have been removed to the Vatican.
The bird has inspired numerous writers, including Amy Clampitt, who wrote a poem called "The Cormorant in its Element". The species she described may have been the pelagic cormorant, which is the only species in the temperate U.S. with the "slim head ... vermilion-strapped" and "big black feet" that she mentions.
Cormorants (and books about them written by a fictional ornithologist) are a recurring fascination of the protagonist in Jesse Ball's 2018 novel Census.
The anhinga (; Anhinga anhinga), sometimes called snakebird, darter, American darter, or water turkey, is a water bird of the warmer parts of the Americas. The word anhinga comes from the Brazilian Tupi language and means devil bird or snake bird. The origin of the name snakebird is apparent when swimming: only the colored neck appears above water so the bird looks like a snake ready to strike. They do not have external nares (nostrils) and breathe solely through their epiglottis.
The anhinga is placed in the darter family, Anhingidae, and is closely related to Indian (Anhinga melanogaster), African (Anhinga rufa), and Australian (Anhinga novaehollandiae) darters. Like other darters, the anhinga hunts by spearing fish and other small prey using its sharp, slender beak.Black-faced cormorant
The black-faced cormorant (Phalacrocorax fuscescens), also known as the black-faced shag, is a medium-sized member of the cormorant family. Upperparts, including facial skin and bill, are black, with white underparts. It is endemic to coastal regions of southern Australia.Booby
A booby is a seabird in the genus Sula, part of the Sulidae family. Boobies are closely related to the gannets (Morus), which were formerly included in Sula.Brown booby
The brown booby (Sula leucogaster) is a large seabird of the booby family, Sulidae, of which it is perhaps the most common and widespread species. It has a pantropical range, which overlaps with that of other booby species. The gregarious brown booby commutes and forages at low height over inshore waters. Flocks plunge-dive to take small fish, especially when these are driven near the surface by their predators. They only nest on the ground, and roost on solid objects rather than the water surface.Cormorant culling
Cormorant culling is the intentional killing of cormorants by humans for the purposes of wildlife management. It has been practiced for centuries, with supporters of culling generally arising from the angling community. Culling techniques may involve the killing of birds, the destruction of eggs or both. Historically, culls have occurred to protect the interests of recreational and commercial fishermen who perceive the animals to be competing with them for their intended catch or for the prey of their intended catch. Since the 1960s, the growing aquaculture industry has undertaken cormorant culls to protect its farmed fish and crustacean stocks. Opponents of cormorant culling include conservation groups such as the National Audubon Society, Cormorant Defenders International and Sea Shepherd.Cormorant fishing
Cormorant fishing is a traditional fishing method in which fishermen use trained cormorants to fish in rivers. Historically, cormorant fishing has taken place in Japan, China and Korea, as well as Greece, North Macedonia, and, briefly, England and France. It is described as a method used by the ancient Japanese in the Book of Sui, the official history of the Sui Dynasty of China, completed in 636 AD. This technique has also been used in other countries but is currently under threat in China.To control the birds, the fishermen tie a snare near the base of the bird's throat. This prevents the birds from swallowing larger fish, which are held in their throat, but the birds can swallow smaller fish. When a cormorant has caught a fish in its throat, the fisherman brings the bird back to the boat and has the bird spit the fish up. Though cormorant fishing once was a successful industry, its primary use today is to serve the tourism industry.
The types of cormorants used differ based on the location. In Gifu, Japan, the Japanese cormorant (P. capillatus) is used; Chinese fishermen often employ great cormorants (P. carbo). Darters (anhinga), which are very close relatives of cormorants, are also used for this fishing technique on occasion.Double-crested cormorant
The double-crested cormorant (Phalacrocorax auritus) is a member of the cormorant family of seabirds. Its habitat is near rivers and lakes as well as in coastal areas, and is widely distributed across North America, from the Aleutian Islands in Alaska down to Florida and Mexico. Measuring 70–90 cm (28–35 in) in length, it is an all-black bird which gains a small double crest of black and white feathers in breeding season. It has a bare patch of orange-yellow facial skin. Five subspecies are recognized. It mainly eats fish and hunts by swimming and diving. Its feathers, like those of all cormorants, are not waterproof and it must spend time drying them out after spending time in the water. Once threatened by the use of DDT, the numbers of this bird have increased markedly in recent years.European shag
The European shag or common shag (Phalacrocorax aristotelis) is a species of cormorant. It breeds around the rocky coasts of western and southern Europe, southwest Asia and north Africa, mainly wintering in its breeding range except for the northernmost birds. In Britain this seabird is usually referred to as simply the shag. The scientific genus name is Latinised Ancient Greek, from φαλακρός (phalakros, "bald") and κόραξ (korax, "raven"). The species name aristotelis commemorates the Greek philosopher Aristotle.Gannet
Gannets are seabirds comprising the genus Morus, in the family Sulidae, closely related to boobies. "Gannet" is derived from Old English ganot "strong or masculine", ultimately from the same Old Germanic root as "gander". Morus is derived from Ancient Greek moros, "foolish", due to the lack of fear shown by breeding gannets and boobies allowing them to be easily killed.The gannets are large white birds with yellowish heads; black-tipped wings; and long bills. Northern gannets are the largest seabirds in the North Atlantic, having a wingspan of up to 2 metres (6.6 ft). The other two species occur in the temperate seas around southern Africa, southern Australia and New Zealand.
Gannets hunt fish by diving into the sea from a height and pursuing their prey underwater. Gannets have a number of adaptations which enable them to do this:
no external nostrils, they are located inside the mouth instead;
air sacs in the face and chest under the skin which act like bubble wrapping, cushioning the impact with the water;
positioning of the eyes far enough forward on the face for binocular vision, allowing them to judge distances accurately.Gannets can dive from a height of 30 metres (98 ft), achieving speeds of 100 kilometres per hour (62 mph) as they strike the water, enabling them to catch fish much deeper than most airborne birds.
The gannet's supposed capacity for eating large quantities of fish has led to "gannet" becoming a description of somebody with a voracious appetite.Great cormorant
The great cormorant (Phalacrocorax carbo), known as the great black cormorant across the Northern Hemisphere, the black cormorant in Australia, the large cormorant in India and the black shag further south in New Zealand, is a widespread member of the cormorant family of seabirds. The genus name is Latinised Ancient Greek, from φαλακρός (phalakros, "bald") and κόραξ (korax, "raven"), and carbo is Latin for "charcoal".It breeds in much of the Old World and the Atlantic coast of North America.HMCS Cormorant (ASL 20)
HMCS Cormorant was a diving support vessel that served in the Canadian Forces. She was equipped with two SDL-1 submersibles. The ship was the first in the Canadian Forces to have women assigned to their crew. Initially constructed as the trawler Aspa Quarto in 1965, the ship was acquired by the Canadian Forces in 1975 and renamed Cormorant. The vessel remained in service until 1997 when Cormorant was sold to a US buyer. The ship was laid up and is awaiting disposal.Imperial shag
The imperial shag (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 the International Ornithologists' Union, place it in the genus Leucocarbo, others in the genus Phalacrocorax . It is also known as the blue-eyed shag, blue-eyed cormorant and by many other names, and is one of a larger group of cormorants called blue-eyed shags. The taxonomy is very complex, and several former subspecies are often considered separate species.Indian cormorant
The Indian cormorant or Indian shag (Phalacrocorax fuscicollis) is a member of the cormorant family. It is found mainly along the inland waters of the Indian Subcontinent but extending west to Sind and east to Thailand and Cambodia. It is a gregarious species that can be easily distinguished from the similar sized little cormorant by its blue eye, small head with a sloping forehead and a long narrow bill ending in a hooked tip.Little cormorant
The little cormorant (Microcarbo niger) is a member of the cormorant family of seabirds. Slightly smaller than the Indian cormorant it lacks a peaked head and has a shorter beak. It is widely distributed across the Indian Subcontinent and extends east to Java, where it is sometimes called the Javanese cormorant. It forages singly or sometimes in loose groups in lowland freshwater bodies, including small ponds, large lakes, streams and sometimes coastal estuaries. Like other cormorants, it is often found perched on a waterside rock with its wings spread out after coming out of the water. The entire body is black in the breeding season but the plumage is brownish, and the throat has a small whitish patch in the non-breeding season. These birds breed gregariously in trees, often joining other waterbirds at heronries.Neotropic cormorant
The Neotropic cormorant or olivaceous cormorant (Phalacrocorax brasilianus) is a medium-sized cormorant found throughout the American tropics and subtropics, from the middle Rio Grande and the Gulf and Californian coasts of the United States south through Mexico and Central America to southern South America, where he is called by the Indian name of "biguá". It also breeds on the Bahamas, Cuba and Trinidad. It can be found both at coasts (including some mangrove areas) and on inland waters. There are at least two subspecies: P. b. mexicanus from Nicaragua northwards and P. b. brasilianus further south. In Peru the Neotropic cormorant is used by the Uru people for fishing.Pygmy cormorant
The pygmy cormorant (Microcarbo pygmaeus) is a member of the Phalacrocoracidae (cormorant) family of seabirds. It breeds in south-eastern Europe and south-western Asia. It is partially migratory, with northern populations wintering further south, mostly within its breeding range. It is a rare migrant to western Europe.Reed cormorant
The reed cormorant (Microcarbo africanus), also known as the long-tailed cormorant, is a bird in the cormorant family Phalacrocoracidae. It breeds in much of Africa south of the Sahara, and Madagascar. It is resident but undertakes some seasonal movements.Sulidae
The bird family Sulidae comprises the gannets and boobies. Collectively called sulids, they are medium-large coastal seabirds that plunge-dive for fish and similar prey. The ten species in this family are often considered congeneric in older sources, placing all in the genus Sula. However, Sula (true boobies) and Morus (gannets) can be readily distinguished by morphological, behavioral, and DNA sequence characters. Abbott's booby (Papasula) is given its own genus as it stands apart from both in these respects. It appears to be a distinct and ancient lineage, maybe closer to the gannets than to the true boobies.Suliformes
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 been suggested that the group be split up to reflect the true evolutionary relationships.
|In the arts|