Pauxi unicornis 

Scope: Global
Language: English

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Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Aves Galliformes Cracidae

Scientific Name: Pauxi unicornis Bond & Meyer de Schauensee, 1939
Common Name(s):
English Horned Curassow
Taxonomic Source(s): del Hoyo, J., Collar, N.J., Christie, D.A., Elliott, A. and Fishpool, L.D.C. 2014. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Volume 1: Non-passerines. Lynx Edicions BirdLife International, Barcelona, Spain and Cambridge, UK.
Taxonomic Notes: Pauxi unicornis and P. koepckeae (del Hoyo and Collar 2014) were previously lumped as P. unicornis following Sibley and Monroe (1990, 1993).
Identification information: 85-95 cm. Large, black cracid with long frontal casque. All-black, with white vent and tip to tail. Bright red bill and pale blue casque shaped as an upright horn, in contrast to P. koepckeae  which has a casque that is flattened against the head and is shorter and rounder. P. koepckeae also has only a thin white tip to the tail. The legs are normally pale red but yellowish in the male in the breeding season. Female like male, but also has a rufous colour phase. Voice A booming series of four phrases lasting c.9 seconds and repeated every 15 seconds, final phrase is a far carrying emphatic hmm.  Alarm call is an explosive disyllabic k-sop. Hints Best located when booming during the main part of the breeding season (probably August-December), but separation from booming Razor-billed Curassow Mitu tuberosa is difficult unless close enough to hear all phrases.

Assessment Information [top]

Red List Category & Criteria: Critically Endangered A2bcd+3cd+4bcd ver 3.1
Year Published: 2016
Date Assessed: 2016-10-01
Assessor(s): BirdLife International
Reviewer(s): Butchart, S. & Symes, A.
Contributor(s): Fjeldså, J., Gastañaga, M., Hennessey, A., Lloyd, H., MacLeod, R., Maccormack, A. & Soria, R.
Facilitator/Compiler(s): Benstead, P., Keane, A., Sharpe, C J, Symes, A., Martin, R, Taylor, J. & Ashpole, J
This species qualifies as Critically Endangered because its population is now estimated to be declining extremely rapidly owing to hunting and habitat destruction. It also has a small range and is known from few locations in a narrow altitudinal band, which is subject to habitat loss.

Previously published Red List assessments:

Geographic Range [top]

Range Description:Pauxi unicornis is known to occur only in central Bolivia. It is known from the adjacent Amboró and Carrasco National Parks (Cox et al. 1997, Herzog and Kessler 1998, Mee 1999, R. MacLeod in litt. 2000) and has more recently been found in Isiboro-Secure Indigenous Territory and National Park (TIPNIS) and along the outer edge of the Cordillera Mosetenes, Cochabamba, Bolivia (R. MacLeod in litt. 2007). It was formerly found along the length of Carrasco's northern boundary (R. MacLeod in litt. 2000), but recent surveys found it in very few locations here (R. MacLeod in litt. 2007). Extensive searches over several years have failed to locate the species in Madidi National Park, La Paz, Bolivia (R. MacLeod in litt. 2003, Hennessey 2004a, A. MacCormick in litt. 2004), in the rio Tambopata area near the Peru/Bolivia border (R. MacLeod in litt. 2004, Gastañaga and Hennessey 2005) and in the Cordillera Cocapata and along the inner edge of Cordillera Mosetenes in Cochabamba (R. MacLeod in litt. 2003, R. MacLeod in litt. 2007). The species occurs at densities of up to 20 individuals/km2, although this appears to be exceptional and at most sites only one or two individuals have been found (R. MacLeod in litt. 2007, del Hoyo and Motis 2004).

Countries occurrence:
Bolivia, Plurinational States of
Additional data:
Continuing decline in area of occupancy (AOO):Yes
Extreme fluctuations in area of occupancy (AOO):NoEstimated extent of occurrence (EOO) - km2:10700
Continuing decline in extent of occurrence (EOO):YesExtreme fluctuations in extent of occurrence (EOO):No
Number of Locations:6-10Continuing decline in number of locations:Unknown
Extreme fluctuations in the number of locations:NoLower elevation limit (metres):450
Upper elevation limit (metres):1150
Range Map:Click here to open the map viewer and explore range.

Population [top]

Population:This species is poorly known; the total population is estimated to number 1,000-4,999 mature individuals, roughly equivalent to 1,500-7,500 individuals in total.

Trend Justification:  A model of forest loss in the Amazon basin since 2002 (Soares-Filho et al. 2006), combined with the species’s approximate range and data on its ecology and life history (following the methods of Bird et al. 2011), suggests that the species will lose 20-30% of suitable habitat in the Amazonian portion of its range (as defined by the model, and which accounts for 98% of its global extent of suitable habitat) over 44 years (estimate of three generations).

Field surveys in Carrasco National Park between 1998 and 2004 suggest the species is extremely vulnerable to hunting. In one valley it declined from at least 20 singing territorial males in 1999 to none in 2004, and similar or even greater human encroachment/hunting pressure has taken place elsewhere within the range (R. MacLeod and R. W. Soria-Auza in litt. 2014). It therefore seems reasonable to suspect there has been a population decline of >80% since the 1990s, and given the presumed further increase in hunting pressure as the entire population becomes within close range of human settlement, without effective protection of national parks (which does not currently exist) the species could be effectively extinct in the wild within 20-30 years (R. MacLeod in litt. 2014). The population trend is therefore placed in the band 80-100% over three generations.
Current Population Trend:Decreasing
Additional data:
Number of mature individuals:1000-4999Continuing decline of mature individuals:Yes
Extreme fluctuations:NoPopulation severely fragmented:No
No. of subpopulations:2-100Continuing decline in subpopulations:Unknown
Extreme fluctuations in subpopulations:NoAll individuals in one subpopulation:No

Habitat and Ecology [top]

Habitat and Ecology:P. unicornis inhabits dense, humid, lower montane forest and adjacent lowland evergreen forest at 450-1,150 m (R. MacLeod in litt. 2000, Maillard 2006, Gastañaga et al. 2011). For much of the year it stays above 550 m, but descends in the dry season (Renjifo and Renjifo 1997). At any one part of its range the species tends to be restricted to an altitudinal band of c.500 m but the upper and lower limits of this vary from location to location. Its diet consists of fruit, seeds, soft plants, larvae and insects. Fallen almendrillo nuts from the almond tree apparently a major food source (del Hoyo et al. 2014). Display songs and pairing have been noted from August (R. MacLeod in litt. 2000), with a nest found during October (Cox et al. 1997). The clutch-size is probably two (R. MacLeod in litt. 2007), as in other Cracidae, (although in the only nest ever found there was only one egg) and consequently it has a low reproductive rate (Cox et al. 1997, Renjifo and Renjifo 1997, Banks 1998).

Continuing decline in area, extent and/or quality of habitat:Yes
Generation Length (years):14.5
Movement patterns:Not a Migrant

Threats [top]

Major Threat(s): In Bolivia, forests within its altitudinal range are being cleared for the cultivation of staple and export crops by recent colonists from the altiplano (Dinerstein et al. 1995, Fjeldså in litt. 1999, Maillard 2006). Road-building and associated rural development have a negative impact and inhibit dispersal (Herzog and Kessler 1998, Fjeldså in litt. 1999). Hunting for its meat seems to be by far the biggest threat and is likely to be having a serious negative impact in all parts of its range (Gastañaga 2006, R. MacLeod in litt. 2014). Human encroachment (for the growing of coca and other farming) and severe hunting pressure is increasing throughout the range, including in national parks, which lack effective protection, and effective extinction in the wild may take place within 20-30 years unless massive conservation action can be achieved (R. MacLeod in litt. 2014).

Conservation Actions [top]

Conservation Actions: Conservation and research actions underway
Large parts of its range are theoretically protected by Amboró and Carrasco National Parks and TIPNIS, although these protected areas are seriously threatened since they have suffered from recent invasions (MacLeod et al. 2006), and have no effective protection.

Conservation and research actions proposed
Conduct field studies to locate and estimate the size of the surviving population and to determine its conservation requirements and vulnerability to human encroachment. Work with the Carrasco and Amboro National Parks and local communities to develop and implement conservation management plans for the species and its habitat. Develop work with local educators and schools to inform local people about the conservation importance and uniqueness of the species and its habitat to their area. Work with local communities to promote a community based hunting ban for the species and to reduce human pressure on its habitat. Identify and implement measures that will measurably improve the livelihoods of the local communities in return for their assistance in conserving the species.

Citation: BirdLife International. 2016. Pauxi unicornis. The IUCN Red List of Threatened Species 2016: e.T45090397A95140681. . Downloaded on 16 August 2018.
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