:''The name vasa parrot is also used for the greater vasa parrot.'' The vasa parrots (''Coracopsis'') are four

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 appropriate s ...

parrot Parrots, also known as psittacines (), are birds of the roughly 398 species in 92 genera comprising the order Psittaciformes (), found mostly in tropical and subtropical regions. The order is subdivided into three superfamilies: the Psittacoide ...

which are endemic to

Madagascar Madagascar (; mg, Madagasikara, ), officially the Republic of Madagascar ( mg, Repoblikan'i Madagasikara, links=no, ; french: République de Madagascar), is an island country in the Indian Ocean, approximately off the coast of East Africa ...

and other

island An island (or isle) is an isolated piece of habitat that is surrounded by a dramatically different habitat, such as water. Very small islands such as emergent land features on atolls can be called islets, skerries, cays or keys. An island ...

s in the western

Indian Ocean The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or ~19.8% of the water on Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia to the east. To the south it is bounded by th ...

. Some taxonomists formerly placed the genus in '' Mascarinus'', but this is now thought to be based on the results of a heavily flawed, later-debunked genetic study.

Taxonomy

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 ...

'' Coracopsis'' was introduced in 1832 by the German ornithologist

Johann Georg Wagler Johann Georg Wagler (28 March 1800 – 23 August 1832) was a German herpetologist and ornithologist. Wagler was assistant to Johann Baptist von Spix, and gave lectures in zoology at the Ludwig Maximilian University of Munich after it was moved ...

. 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 ...

was designated as the

lesser vasa parrot The lesser vasa parrot or black parrot (''Coracopsis nigra'') is a black coloured parrot endemic to most of Madagascar. It is one of four species of vasa parrots, the others being the greater vasa parrot ''C. vasa'', the Seychelles black parrot ...

George Robert Gray George Robert Gray FRS (8 July 1808 – 6 May 1872) was an English zoologist and author, and head of the ornithological section of the British Museum, now the Natural History Museum, in London for forty-one years. He was the younger brother ...

in 1840.

Species

The genus contains four species: *''Coracopsis vasa'', (Shaw) 1812 – (

greater vasa parrot The greater vasa parrot (''Coracopsis vasa'') is one of two species of vasa parrot, the other being the lesser vasa parrot ''C. nigra''. The greater vasa parrot can be found throughout Madagascar and the Comoros. Taxonomy The bird was describ ...

) **''Coracopsis vasa comorensis'', (Peters,W) 1854 **''Coracopsis vasa drouhardi'', Lavauden 1929 **''Coracopsis vasa vasa'', (Shaw) 1812 *''Coracopsis nigra'', (Linnaeus) 1758 – (

also known as black parrot) **''Coracopsis nigra libs'', Bangs 1927 **''Coracopsis nigra nigra'', (Linnaeus) 1758 *''Coracopsis sibilans'', Milne-Edwards & Oustalet 1885 ( Comoros black parrot) (split from ''Coracopsis nigra'') *''Coracopsis barklyi'', Newton 1867 – (

Seychelles black parrot The Seychelles black parrot, Praslin parrot or kato nwar (''Coracopsis barklyi'') is a sombre-coloured, medium-sized parrot endemic to the Seychelles. Historically, it has been treated as a subspecies of the lesser vasa parrot, although it shows ...

)

Phylogeny

A 2011 genetic study found the

Mascarene parrot The Mascarene parrot or mascarin (''Mascarinus mascarinus'') is an extinct species of parrot that was endemic to the Mascarene island of Réunion in the western Indian Ocean. The taxonomic relationships of this species have been subject to ...

from

Réunion Réunion (; french: La Réunion, ; previously ''Île Bourbon''; rcf, label= Reunionese Creole, La Rényon) is an island in the Indian Ocean that is an overseas department and region of France. It is located approximately east of the island ...

to be nested among the subspecies of the lesser vasa parrot from Madagascar and nearby islands, and therefore not related to the ''Psittacula'' parrots. It also found that the Mascarene parrot line diverged 4.6 to 9 million years ago, prior to the formation of Réunion, indicating this must have happened elsewhere. The

cladogram A cladogram (from Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an evolutionary tree because it does not show how ancestors are related to d ...

accompanying the study is shown below: Another group of scientists later acknowledged the finding, but pointed out that the sample might have been damaged, and that further testing was needed before the issue could be fully resolved. They also noted that if ''Mascarinus'' was confirmed to be embedded within the genus ''Coracopsis'', the latter would become a junior synonym, since the former name is older. Hume has expressed surprise by these findings, due to the anatomical similarities between the Mascarene parrot and other parrots from the islands that are believed to be psittaculines. However, a later study found that the placement of ''Mascarinus'' within ''Coracopsis'' was likely a result of cross-contamination of genetic material during the study, debunking this placement, and supporting them as being two distinct, unrelated genera within different subfamilies.

Description

They are notable in the parrot world for their peculiar appearance, which includes extremely truncated bodies with long necks, black to grey feathers and a pink

beak The beak, bill, or rostrum is an external anatomical structure found mostly in birds, but also in turtles, non-avian dinosaurs and a few mammals. A beak is used for eating, preening, manipulating objects, killing prey, fighting, probing for food ...

. The skin of both female and male vasas turns yellow during the breeding season, and there is often feather loss. However, in females the feather loss can result in complete baldness. Another interesting feature of the females breeding

physiology Physiology (; ) is the scientific study of functions and mechanisms in a living system. As a sub-discipline of biology, physiology focuses on how organisms, organ systems, individual organs, cells, and biomolecules carry out the chemical ...

is when her feathers, which are usually black to grey, turn brown without a moult. This is caused by the redistribution of

melanin Melanin (; from el, μέλας, melas, black, dark) is a broad term for a group of natural pigments found in most organisms. Eumelanin is produced through a multistage chemical process known as melanogenesis, where the oxidation of the amino ...

, which is the

pigment A pigment is a colored material that is completely or nearly insoluble in water. In contrast, dyes are typically soluble, at least at some stage in their use. Generally dyes are often organic compounds whereas pigments are often inorganic compo ...

that makes the vasas' feathers black.

Unusual characteristics

In addition to their appearance they possess aspects of their physiology that make them unique amongst parrots. Vasa chicks are known to hatch after only 18–20 days of incubation, which is highly irregular as parrots of the vasa size range tend to take up to 30 days to hatch. The male vasas' cloaca is able to invert into a

hemipenis A hemipenis (plural hemipenes) is one of a pair of intromittent organs of male squamates (snakes, lizards and worm lizards). Hemipenes are usually held inverted within the body, and are everted for reproduction via erectile tissue, much like ...

, which becomes erect during mating – a feature unique to the

. This phallus is associated with prolonged matings enforced by a

copulatory tie Canine reproduction is the process of sexual reproduction in domestic dogs, wolves, coyotes and other canine species. Canine sexual anatomy and development Male reproductive system Erectile tissue As with all mammals, a dog's penis is made up o ...

. Baby vasas possess pads on their beaks which when stimulated prompt a strong feeding response. These pads disappear after only a few weeks, however the feeding or 'weaning' reflex remains unusually strong well into adulthood. Often aviculturalists have to use a syringe to force food into the crops of young vasas as the intensity of the weaning reflex prevents them from being spoon fed. Vasa parrots infected with the debilitating psittacine beak and feather disease are known to turn white, which, during the 1970s when the first wave of birds were exported into

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...

and America, resulted in them being mistakenly advertised by importers as

albino Albinism is the congenital absence of melanin in an animal or plant resulting in white hair, feathers, scales and skin and pink or blue eyes. Individuals with the condition are referred to as albino. Varied use and interpretation of the term ...

References

*Kundu, S., C.G. Jones, R.P. Prys-Jones, and J.J. Groombridge. 2012. The evolution of the Indian Ocean parrots (Psittaciformes): extinction, adaptive radiation and eustacy. Molecular Phylogenetics and Evolution 62: 296–305. {{Taxonbar, from=Q869053 Parrots