Weske & Terborgh, 1971
Pauxi unicornis koepckeae
The Sira Curassow (Pauxi koepckeae) is a species of bird in the Cracidae family. It is found in the Cerros del Sira in southeastern Peru. Its natural habitats are subtropical or tropical moist lowland forests and subtropical or tropical moist montane forests.
It is threatened by habitat loss.
Taxonomy and systematics
In 1969 another two birds, a male and female were discovered which resembled Horned Curassow. However 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.
Many different suggestions have been regarding species status 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 6.5 mya.
P. koepckeae is only known from a very small geographic area and a small number of specimens. Recent work suggests that P. koepckeae be considered distinct based on vocal, behavioral, ecological, and morphological differences.
The Sira Curassow is very similar morphologically to the Horned Curassow, however 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.
- Weske, J.S. & Terborgh, J.W. (1971). "A New Subspecies of Curassow of the Genus Pauxi from Peru". The Auk 88 (2): 233–238. doi:10.2307/4083876.
- 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.
- 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. doi:10.1017/S0959270900001532.
- 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. doi:10.1642/0004-8038(2004)121[0682:VSOCAC]2.0.CO;2.
- Gastañaga-C., M., MacLeod, R.; Brooks, D.M. and Hennessey, B. (2011). "Distinctive morphology, ecology, and first vocal descriptions of Sira Curassow (Pauxi [unicornis] koepckeae): evidence for species rank". Ornitol. Neotrop. 22: 267–279.
- Gastañaga, M. & Hennessey, A.B (2005). "Uso de información local para reevaluar la población de Pauxi unicornis en Perú". Cotinga (in Spanish) 23: 18–22.
- Gastañaga, M. 2006. Peruvian Horned Curassow (Pauxi unicornis koepckeae) rediscovered in the Sira Mountains, Peru. Bulletin of the Cracid Specialist Group 22: 10–23.
- Gastañaga, M., A. B. Hennessey, & R. MacLeod. 2007. Rediscovery of Southern Horned Curassow Pauxi unicornis koepckeae in Cerros del Sira, Peru. Cotinga 28: 63–66.
- Graham, J.G. (2009). "A new specimen of Southern Horned Curassow Pauxi unicornis from Peru". Cotinga 31: 73.
- Hennessey, A.B. (2004) Unbiased local information survey methods confirms southern helmeted curassow (Pauxi unicornis koepckeae) for Peru. Bol. CSG 19: 16–19.
- 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.
- Pereira, S.L.; Baker, A.J.; Wajntal, A. (2002). "Combined nuclear and mitochondrial DNA sequences resolve generic relationships within the Cracidae (Galliformes, Aves)". Systematic Biology 51 (6): 946–958. doi:10.1080/10635150290102519. PMID 12554460.
|Wikispecies has information related to: Pauxi unicornis|
- South American Classification Committee (November 23rd 2012). "Proposal (#537) to South American Classification Committee – Elevate Pauxi unicornis koepckeae to species status". Retrieved December 8, 2012.
- BirdLife Species Factsheet.
- Cracid Specialist Group