Vasa parrot
Encyclopedia
The vasa parrots are two species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

 of parrot
Parrot
Parrots, also known as psittacines , are birds of the roughly 372 species in 86 genera that make up the order Psittaciformes, found in most tropical and subtropical regions. The order is subdivided into three families: the Psittacidae , the Cacatuidae and the Strigopidae...

 which are endemic to Madagascar
Madagascar
The Republic of Madagascar is an island country located in the Indian Ocean off the southeastern coast of Africa...

 and other island
Island
An island or isle is any piece of sub-continental land that is surrounded by water. Very small islands such as emergent land features on atolls can be called islets, cays or keys. An island in a river or lake may be called an eyot , or holm...

s in the western Indian Ocean
Indian Ocean
The Indian Ocean is the third largest of the world's oceanic divisions, covering approximately 20% of the water on the Earth's surface. It is bounded on the north by the Indian Subcontinent and Arabian Peninsula ; on the west by eastern Africa; on the east by Indochina, the Sunda Islands, and...

.

Taxonomy

There are two species and several subspecies:

Coracopsis, Wagler 1832
  • Coracopsis vasa, (Shaw) 1812 - (Greater Vasa Parrot
    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...

    )
    • Coracopsis vasa comorensis, (Peters,W) 1854
    • Coracopsis vasa drouhardi, Lavauden 1929
    • Coracopsis vasa vasa, (Shaw) 1812
  • Coracopsis nigra, (Linnaeus) 1758 - (Lesser Vasa Parrot
    Lesser Vasa Parrot
    The Lesser Vasa Parrot or Black Parrot Coracopsis nigra is a black coloured parrot native to Comoros, Madagascar, Mayotte, and Seychelles. It is one of two species of vasa parrots, the other being the Greater Vasa Parrot C. vasa; although, the subspecies C. n...

     also known as Black Parrot)
    • Coracopsis nigra libs, Bangs 1927
    • Coracopsis nigra nigra, (Linnaeus) 1758
    • Coracopsis nigra sibilans, Milne-Edwards & Oustalet 1885
    • Coracopsis nigra barklyi, Newton 1867

Additionally, a recent study using ancient DNA shows that the Mascarene Parrot
Mascarene Parrot
The Mascarene Parrot is an extinct species of parrot known from bones, specimens and descriptions to have occurred in the Mascarene island of Réunion, and possibly Mauritius. The bird was first described by Dubois in 1674...

 is positioned in between the various subspecies of the Lesser Vasa Parrot; however, the binomial name of the Mascarene Parrot has not been officially updated.
  • Mascarinus mascarinus, (Linnaeus 1771) (Mascarene Parrot
    Mascarene Parrot
    The Mascarene Parrot is an extinct species of parrot known from bones, specimens and descriptions to have occurred in the Mascarene island of Réunion, and possibly Mauritius. The bird was first described by Dubois in 1674...

    , extinct)

Description

They are notable in the parrot world for their peculiar appearance, which includes extremely truncated bodies with long necks, black to grey feather
Feather
Feathers are one of the epidermal growths that form the distinctive outer covering, or plumage, on birds and some non-avian theropod dinosaurs. They are considered the most complex integumentary structures found in vertebrates, and indeed a premier example of a complex evolutionary novelty. They...

s and a pink beak
Beak
The beak, bill or rostrum is an external anatomical structure of birds which is used for eating and for grooming, manipulating objects, killing prey, fighting, probing for food, courtship and feeding young...

.

The skin of both female and male vasas turns yellow during the breeding season
Breeding season
The breeding season is the most suitable season, usually with favourable conditions and abundant food and water, for breeding among some wild animals and birds . Species with a breeding season have naturally evolved to have sexual intercourse during a certain time of year in order to achieve the...

, 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
Physiology is the science of the function of living systems. This includes how organisms, organ systems, organs, cells, and bio-molecules carry out the chemical or physical functions that exist in a living system. The highest honor awarded in physiology is the Nobel Prize in Physiology or...

 is when her feathers, which are usually black to grey, turn brown without a moult. This is caused by the redistribution of melanin
Melanin
Melanin is a pigment that is ubiquitous in nature, being found in most organisms . In animals melanin pigments are derivatives of the amino acid tyrosine. The most common form of biological melanin is eumelanin, a brown-black polymer of dihydroxyindole carboxylic acids, and their reduced forms...

, which is the pigment
Pigment
A pigment is a material that changes the color of reflected or transmitted light as the result of wavelength-selective absorption. This physical process differs from fluorescence, phosphorescence, and other forms of luminescence, in which a material emits light.Many materials selectively absorb...

 that makes the vasas' feathers black.

Unusual characteristics

In addition to their appearance they possess aspects of their physiology that make them completely unique amongst parrots. Vasa chicks are known to hatch after only 18–20 days of incubation
Avian incubation
Incubation refers to the process by which certain oviparous animals hatch their eggs, and to the development of the embryo within the egg. The most vital factor of incubation is the constant temperature required for its development over a specific period. Especially in domestic fowl, the act of...

, which is highly irregular as parrots of the vasa size range tend to take up to 30 days to hatch.

The male vasas' cloaca
Cloaca
In zoological anatomy, a cloaca is the posterior opening that serves as the only such opening for the intestinal, reproductive, and urinary tracts of certain animal species...

 is able to invert into a hemipenis
Hemipenis
A hemipenis is one of a pair of intromittent organs of male squamates .Hemipenes are usually held inverted, within the body, and are everted for reproduction via erectile tissue, much like that in the human penis. Only one is used at a time, and some evidence indicates males alternate use between...

, which becomes erect during mating - a feature unique to 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...

. This phallus is associated with prolonged matings enforced by a copulatory tie. 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
Reflex
A reflex action, also known as a reflex, is an involuntary and nearly instantaneous movement in response to a stimulus. A true reflex is a behavior which is mediated via the reflex arc; this does not apply to casual uses of the term 'reflex'.-See also:...

 remains unusually strong well into adulthood. Often aviculturalists have to use a syringe
Syringe
A syringe is a simple pump consisting of a plunger that fits tightly in a tube. The plunger can be pulled and pushed along inside a cylindrical tube , allowing the syringe to take in and expel a liquid or gas through an orifice at the open end of the tube...

 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
Psittacine beak and feather disease
Psittacine beak and feather disease is a viral disease affecting all Old World and New World Parrots . The virus belongs to the family Circoviridae. The virus attacks the feather follicles and the beak and claws-growing cells of the bird, causing progressive feather malformation and necrosis...

 are known to turn white, which, during the 1970s when the first wave of birds were exported into Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

 and America
Americas
The Americas, or America , are lands in the Western hemisphere, also known as the New World. In English, the plural form the Americas is often used to refer to the landmasses of North America and South America with their associated islands and regions, while the singular form America is primarily...

, resulted in them being mistakenly advertised by importers as albinos.
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