Horned Curassow

Horned Curassow
Conservation status
Endangered (IUCN 3.1)
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Aves
Order:	Galliformes
Family:	Cracidae
Genus:	Pauxi
Species:	P. unicornis
Binomial name
Pauxi unicornis Bond & Meyer de Schauensee, 1939
P. u. unicornis P. u. koepckeae
Synonyms
Crax unicornis (Bond & Meyer de Schauensee, 1939)

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 habitats are subtropical or tropical moist lowland forests and subtropical or tropical moist montanes.

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.^[1] 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.^[1]

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 Bond 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.^[2] 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.^[2] The two subspecies of the Southern Helmeted Curassow are therefore:

• P. unicornis unicornis Bond & Meyer de Schauensee, 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.^[3][4] 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.^[2][4]

"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."[2]

— 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.^[3] 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.^[2][4][5]

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.^[5] 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.^[5]

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.^[6]

Description

The Horned Curassow is among the largest cracid species with a body length of 85–90 cm. It has a distinctive horn or casque 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.^[4]

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.^[2]

Notes

1. ^ ^{a b} MacLeod 2006
2. ^ ^{a b c d e f} Weske & Terborgh 1971
3. ^ ^{a b} Vaurie 1967
4. ^ ^{a b c d} Cox et. al. 1997
5. ^ ^{a b c} Pereira 2004
6. ^ MacLeod et. al. 2006, p.61

References

• BirdLife International 2005. Pauxi unicornis. 2006 IUCN Red List of Threatened Species. Downloaded on 10 July 2007.
• Cox, G., Read, J.M., Clarke, R.O.S. & Easty, V.S. (1997). "Studies of Horned Curassow Pauxi unicornis in Bolivia". Bird Conservation International 7: 199–211. http://journals.cambridge.org/action/displayAbstract?aid=7441748. 
• Gastañaga, M. & Hennessey, A.B (2005). "Uso de información local para reevaluar la población de Pauxi unicornis en Perú" (in Spanish). Cotinga 23: 18–22. http://www.neotropicalbirdclub.org/articles/23/Gasta%C3%B1aga.pdf. 
• Graham, J.G. (2009). "A new specimen of Southern Horned Curassow Pauxi unicornis from Peru". Cotinga 31: 73. http://www.neotropicalbirdclub.org/articles/31/Graham.pdf. 
• Hennessey, A.B. (2004a) Conservation presentations to Tacana communities within the last Bolivian site of the Wattled Curassow (Crax globulosa). Bol. CSG 19: 9-13.
• Hennessey, A.B. (2004b) Unbiased local information survey methods confirms southern helmeted curassow (Pauxi unicornis koepckeae) for Peru. Bol. CSG 19: 16-19.
• Herzog, H.K.; Kessler, M. (1998). "In search of the last Horned Curassows Pauxi unicornis in Bolivia". Cotinga 10: 46–48. 
• MacLeod, Ross; Soria, Rodrigo; Gastañaga, Melvin (2006). "Horned Curassow (Pauxi unicornis)". In Brooks, D.M.. Conserving Cracids: The most Threatened Family of Birds in the Americas. Miscellaneous Publications of The Houston Museum of Natural Science, Number 6. ISBN 0-9668278-2-1. http://www.cracids.org/AP_Engl_ebook.pdf. 
• Maillard O.Z. (2006). "Reciente Espécimen de la Pava Copete de Piedra (Pauxi unicornis) para Bolivia [Recent specimen of Southern Helmeted Curassow (Pauxi unicornis) for Bolivia]" (in Spanish). Kempffiana 2 (1): 95–98. http://www.museonoelkempff.org/sitio/Informacion/KEMPFFIANA/Kempffiana%202%281%29/95-98.pdf. 
• Mee, A. (1999) Habitat association and notes of the Southern Helmeted Curassow (Pauxi unicornis) in the Yungas of Cochbamba, Bolivia. Bol. CSG 9: 16-19.
• Pereira, S.L. & Baker, A.J. (2004): Vicariant speciation of curassows (Aves, Cracidae): a hypothesis based on mitochondrial DNA phylogeny. Auk 121(3): 682-694. [English with Spanish abstract] doi:10.1642/0004-8038(2004)121[0682:VSOCAC]2.0.CO;2 HTML abstract HTML fulltext without images
• Pereira, S.L.; Baker, A.J.; Wajntal, A. (2002). "Combined nuclear and mitochondrial DNA sequences resolve generic relationships within the Cracidae (Galliformes, Aves)" (PDF). Systematic Biology 51 (6): 946–958. doi:10.1080/10635150290102519. PMID 12554460. http://sysbio.oxfordjournals.org/content/51/6/946. 
• Tobias, J.A. & del Hoyo, J. (2006). "Birding in Bolivia: putting two rare curassows on the map". Neotropical Birding 1: 61–65. http://www.neomorphus.com/work/JPDF/Tobias_del%20Hoyo.pdf. 
• Weske, J.S. & Terborgh, J.W. (1971). "A New Subspecies of Curassow of the Genus Pauxi from Peru". The Auk 88 (2): 233–238. http://elibrary.unm.edu/sora/Auk/v088n02/p0233-p0238.pdf. 
• Vaurie, C. (1967). "Systematic notes on the bird family Cracidae, 10. The genera Mitu and Pauxi and the generic relationships of the Cracini". American Museum novitates 2307: 1–20. hdl:2246/3507. 

External links

• BirdLife Species Factsheet.
• Cracid Specialist Group
• http://www.a2ew.com/photogalleries/SAFauna16.htm