Southern Helmeted Curassow
Encyclopedia
The Horned Curassow or Southern Helmeted Curassow (Pauxi unicornis) is a species of bird
in the Cracidae
family. It is found in Bolivia
and Peru
. Its natural habitat
s are subtropical or tropical moist lowland forest
s and subtropical or tropical moist montane
s.
It is threatened by habitat loss. Until 2004 the Horned Curassow was classified as Vulnerable by the IUCN Red List due to a small and declining population, but was changed to Endangered in 2005 due to an estimated smaller range and greater rinsk from human activities. In Bolivia the potential habitat of subspecies P. unicornis unicornis may cover an area of 4,000 km2 including the national parks: Amboró
, Carrasco
and Isiboro Sécure
. Despite concentrated fieldwork there are many parts of this potential habitat in which no individuals have found, for example the most north west 2,000 km2.
and Rodolphe Meyer de Schauensee
in 1939 and given the scientific name Pauxi unicornis placing it in a genus Pauxi alongside the species P. pauxi. In 1969 another two birds, again a male and female were discovered which resembled those found by Mr. Carriker in 1937. However this time they were found in Peru a long way from the previous P. unicornis discoveries in Bolivia. These Peruvian specimens were described by John Weske and John Terborgh in 1971 as a new subspecies of P. unicornis which they named in honour of Maria Koepcke. The two subspecies of the Southern Helmeted Curassow are therefore:
Although the current consensus is for P. unicornis to be a species with two subspecies in the genus Pauxi, many different suggestions have been made since their discovery. Some suggestions relate to the grouping of species and subspecies within the genus Pauxi. In 1943 Wetmore and Phelps described a new subspecies of the closely related P. pauxi called P. p. gilliardi. When Wetmore and Phelps looked at the three Pauxi forms known at the time, they concluded that P. p. gilliardi was an intermediate form between P. pauxi and P. unicornis. As a result of this they grouped all three forms into a single species with unicornis becoming a subspecies of pauxi. This position was subsequently rejected by Charles Vaurie who argued that P. pauxi and P. unicornis were not conspecific. When Weske and Terborgh discovered the subspecies koepckeae they concluded pauxi and unicornis should be considered separate species, which has been followed by all subsequent authors.
Other taxonomic suggestions discuss whether the genus Pauxi should stand alone or be grouped with other genera. In 1965 François Vuilleumier suggested the two Pauxi species should be moved into a single genus alongside all the other species in the closely related genera Mitu, Crax and Nothocrax. Just two years later Charles Vaurie opposed this 'lumping' of species and argued that Pauxi, Mitu, Crax and Nothocrax should each be their own genera. Not content with either of these two options Delacour and Amadon suggested that Pauxi and Mitu should indeed be grouped with Crax, but that Nothocrax was distinct enough to be its on genus. Many subsequent authors followed Vaurie, Delacour and Amadon in having Nothocrax as a sister clade to Pauxi, Mitu and Crax, while most have followed Vaurie in having the three other clades as three distinct genera.
Recent mitochondrial analysis suggests that P. unicornis is a sister species to Mitu tuberosum, while the other Pauxi species, P. pauxi, is sister to the combined Mitu and P. unicornis clade. This means the genus Pauxi is not monophyletic but paraphyletic. The paraphyly of Pauxi could be due to incomplete lineage sorting, where a gene tree is inconsistent with its species tree, however it is less important for deep phyolenetic splits. Because of this, Pereira et al conclude incomplete lineage sorting is unlikely to account for the paraphylic Pauxi genera because, according to their own analysis, Mitu and Pauxi diverged approximately 6.5mya.
P. u. koepckeae is only known from a very small geographic area and a small number of specimens. Urgent work is needed to study the population, as it is thought that it may deserve to be elevated to species level, which would result in it being critically endangered.
on the forehead which projects for over 6 cm. The plummage is generally black, but lacks a blue sheen in primary feathers, and has a white belly, thigh tufts and under-tail coverts. The tail also has white tips.
In the subspecies koepckeae the casque is less erect and more rounded (ellipsoidal instead of elongated cone). Additianally the outer tail feathers have narrower white tips and the four central tail feather completely lack white colouring.
Bird
Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...
in the Cracidae
Cracidae
The chachalacas, guans and curassows are birds in the family Cracidae.These are species of tropical and subtropical Central and South America. One species, the Plain Chachalaca, just reaches southernmost Texas in the USA...
family. It is found in Bolivia
Bolivia
Bolivia officially known as Plurinational State of Bolivia , is a landlocked country in central South America. It is the poorest country in South America...
and Peru
Peru
Peru , officially the Republic of Peru , is a country in western South America. It is bordered on the north by Ecuador and Colombia, on the east by Brazil, on the southeast by Bolivia, on the south by Chile, and on the west by the Pacific Ocean....
. Its natural habitat
Habitat
* Habitat , a place where a species lives and grows*Human habitat, a place where humans live, work or play** Space habitat, a space station intended as a permanent settlement...
s are subtropical or tropical moist lowland forest
Forest
A forest, also referred to as a wood or the woods, is an area with a high density of trees. As with cities, depending where you are in the world, what is considered a forest may vary significantly in size and have various classification according to how and what of the forest is composed...
s and subtropical or tropical moist montane
Montane
In biogeography, montane is the highland area located below the subalpine zone. Montane regions generally have cooler temperatures and often have higher rainfall than the adjacent lowland regions, and are frequently home to distinct communities of plants and animals.The term "montane" means "of the...
s.
It is threatened by habitat loss. Until 2004 the Horned Curassow was classified as Vulnerable by the IUCN Red List due to a small and declining population, but was changed to Endangered in 2005 due to an estimated smaller range and greater rinsk from human activities. In Bolivia the potential habitat of subspecies P. unicornis unicornis may cover an area of 4,000 km2 including the national parks: Amboró
Amboró National Park
Amboró National Park in central Bolivia is a nature reserve with over 800 species of birds, over 125 mammalian species including puma, ocelot, and the rare Spectacled Bear. Covering an area of 4,425 km² , it is protected from human settlements, hunting, mining and deforestation, though...
, Carrasco
Carrasco National Park
Carrasco National Park is a national park in Cochabamba Department, Bolivia. It has a surface area of 6,226 square kilometers. More than 5,000 plant species have been registered in the area, placing the park among Bolivia's most biologically diverse. It is a protected area and people are prohibited...
and Isiboro Sécure
Isiboro Sécure National Park and Indigenous Territory
Isiboro Sécure National Park and Indigenous Territory is a protected area and Native Community Land in Bolivia situated between the north of the Cochabamba Department and the south of the Beni Department...
. Despite concentrated fieldwork there are many parts of this potential habitat in which no individuals have found, for example the most north west 2,000 km2.
Taxonomy and systematics
In 1937 while in Bolivia Mr M. A. Carriker found two birds, a male and female, which were in the cracid family. The specimens were subsequently described as a new species by James BondJames Bond (ornithologist)
James Bond was a leading American ornithologist whose name was appropriated by writer Ian Fleming for his fictional spy, James Bond.-Biography:...
and Rodolphe Meyer de Schauensee
Rodolphe Meyer de Schauensee
Rodolphe Meyer de Schauensee was an American ornithologist.He was born in Rome, and his family moved to the United States in 1913. He was curator of birds at the Academy of Natural Sciences in Philadelphia for nearly fifty years. He was particularly noted for his study of South American birds...
in 1939 and given the scientific name Pauxi unicornis placing it in a genus Pauxi alongside the species P. pauxi. In 1969 another two birds, again a male and female were discovered which resembled those found by Mr. Carriker in 1937. However this time they were found in Peru a long way from the previous P. unicornis discoveries in Bolivia. These Peruvian specimens were described by John Weske and John Terborgh in 1971 as a new subspecies of P. unicornis which they named in honour of Maria Koepcke. The two subspecies of the Southern Helmeted Curassow are therefore:
- P. unicornis unicornis BondJames Bond (ornithologist)James Bond was a leading American ornithologist whose name was appropriated by writer Ian Fleming for his fictional spy, James Bond.-Biography:...
& Meyer de SchauenseeRodolphe Meyer de SchauenseeRodolphe Meyer de Schauensee was an American ornithologist.He was born in Rome, and his family moved to the United States in 1913. He was curator of birds at the Academy of Natural Sciences in Philadelphia for nearly fifty years. He was particularly noted for his study of South American birds...
, 1939. - P. unicornis koepckeae Weske & Terborgh, 1971.
Although the current consensus is for P. unicornis to be a species with two subspecies in the genus Pauxi, many different suggestions have been made since their discovery. Some suggestions relate to the grouping of species and subspecies within the genus Pauxi. In 1943 Wetmore and Phelps described a new subspecies of the closely related P. pauxi called P. p. gilliardi. When Wetmore and Phelps looked at the three Pauxi forms known at the time, they concluded that P. p. gilliardi was an intermediate form between P. pauxi and P. unicornis. As a result of this they grouped all three forms into a single species with unicornis becoming a subspecies of pauxi. This position was subsequently rejected by Charles Vaurie who argued that P. pauxi and P. unicornis were not conspecific. When Weske and Terborgh discovered the subspecies koepckeae they concluded pauxi and unicornis should be considered separate species, which has been followed by all subsequent authors.
| "Through an unfortunate misunderstanding, the female was plucked and prepared for the stewpot by our Peruvian assistants, who did not realize that we wished to preserve both birds as skins." |
| — The unfortunate turn of events after two birds of P. unicornis koepckeae were discovered for the first time. |
Other taxonomic suggestions discuss whether the genus Pauxi should stand alone or be grouped with other genera. In 1965 François Vuilleumier suggested the two Pauxi species should be moved into a single genus alongside all the other species in the closely related genera Mitu, Crax and Nothocrax. Just two years later Charles Vaurie opposed this 'lumping' of species and argued that Pauxi, Mitu, Crax and Nothocrax should each be their own genera. Not content with either of these two options Delacour and Amadon suggested that Pauxi and Mitu should indeed be grouped with Crax, but that Nothocrax was distinct enough to be its on genus. Many subsequent authors followed Vaurie, Delacour and Amadon in having Nothocrax as a sister clade to Pauxi, Mitu and Crax, while most have followed Vaurie in having the three other clades as three distinct genera.
Recent mitochondrial analysis suggests that P. unicornis is a sister species to Mitu tuberosum, while the other Pauxi species, P. pauxi, is sister to the combined Mitu and P. unicornis clade. This means the genus Pauxi is not monophyletic but paraphyletic. The paraphyly of Pauxi could be due to incomplete lineage sorting, where a gene tree is inconsistent with its species tree, however it is less important for deep phyolenetic splits. Because of this, Pereira et al conclude incomplete lineage sorting is unlikely to account for the paraphylic Pauxi genera because, according to their own analysis, Mitu and Pauxi diverged approximately 6.5mya.
P. u. koepckeae is only known from a very small geographic area and a small number of specimens. Urgent work is needed to study the population, as it is thought that it may deserve to be elevated to species level, which would result in it being critically endangered.
Description
The Horned Curassow is among the largest cracid species with a body length of 85–90 cm. It has a distinctive horn or casqueCasque
Casque can refer to:* French word for helmet* An enlargement on the upper mandible of the bill of some species of birds, including many hornbills*Hornbill ivory: the casque of the Helmeted Hornbill, collected as a decorative material...
on the forehead which projects for over 6 cm. The plummage is generally black, but lacks a blue sheen in primary feathers, and has a white belly, thigh tufts and under-tail coverts. The tail also has white tips.
In the subspecies koepckeae the casque is less erect and more rounded (ellipsoidal instead of elongated cone). Additianally the outer tail feathers have narrower white tips and the four central tail feather completely lack white colouring.
External links
- BirdLife Species Factsheet.
- Cracid Specialist Group
- http://www.a2ew.com/photogalleries/SAFauna16.htm