Class Aves Rank Species | Phylum Chordata | |
Similar Horned curassow, East Brazilian chachalaca, Buff‑browed chachalaca, Scaled chachalaca, Crestless curassow | ||
The Sira curassow (Pauxi koepckeae) is a species of bird in the Cracidae family. It is found in the Cerros del Sira in central Peru. Its natural habitats are subtropical or tropical moist lowland forests and subtropical or tropical moist montane forests.
Contents
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.
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.
Description
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). Additionally the outer tail feathers have narrower white tips and the four central tail feather completely lack white colouring.
Conservation
The Sira curassow is listed as critically endangered as it is threatened by habitat destruction and is hunted for meat. The birds population is believed to be below 250 individuals with a decreasing trend.