Cacajao calvus


Taxonomy [top]

Kingdom Phylum Class Order Family

Scientific Name: Cacajao calvus
Species Authority: (I. Geoffroy, 1847)
Infra-specific Taxa Assessed:
Common Name/s:
English Bald-headed Uacari, Bald Uakari, Red-and-white Uacari, Red Uakari
French Ouakari Chauve
Spanish Cacajao, Cacayao, Huapo Colorado, Huapo Rojo, Uacaries
Taxonomic Notes: The taxonomy of Cacajao follows Hernández-Camacho and Cooper (1976), Hershkovitz (1987), Eisenberg (1989) and Boubli (1994). The geographic range of C. c. novaesi is larger than was previously thought, and a new population of white uakaris has been recorded from the Rio Jurupari, a tributary of the Rio Envira, well to the south of C. c. calvus, and separated by the red C. c. novaesi, indicating the need for a reappraisal of the taxonomy and systematics of the species (Silva Jr. and Martins 1999). Following Hershkovitz (1987), four subspecies are retained here: C. c. calvus; C. c. rubicundus; C. c novaesi; and C. c. ucayalii. Although the four subspecies are morphologically distinct, a recent study (based on sixteen specimens) indicates that they are genetically homogeneous (Figueiredo 2006). The species is in urgent need of a taxonomic review and reappraisal of subspecies status.

Assessment Information [top]

Red List Category & Criteria: Vulnerable A2cd ver 3.1
Year Published: 2008
Date Assessed: 2008-06-30
Assessor/s: Veiga, L.M., Bowler, M., Silva Jr., J.S., Queiroz, H.L., Boubli, J.-P. & Rylands, A.B.
Reviewer/s: Mittermeier, R.A. & Rylands, A.B. (Primate Red List Authority)
Listed as Vulnerable as there is reason to believe the species has declined by at least 30% over the past 30 years (three generations) due primarily to hunting and habitat loss.
2003 Near Threatened (IUCN 2003)
2003 Near Threatened
2000 Vulnerable
1996 Vulnerable (Baillie and Groombridge 1996)
1996 Vulnerable
1994 Endangered (Groombridge 1994)
1990 Vulnerable (IUCN 1990)
1988 Vulnerable (IUCN Conservation Monitoring Centre 1988)
1986 Vulnerable (IUCN Conservation Monitoring Centre 1986)
1982 Vulnerable (Thornback and Jenkins 1982)

Geographic Range [top]

Range Description:This species is found in Brazil and Peru. The distribution of the Bald-headed Uacari is poorly known and field surveys are needed to resolve a series of issues related to the distribution and taxonomy of these taxa. Available data suggest that there is no range overlap among the subspecies of Cacajao calvus, although there may be a contact zone between Cacajao calvus calvus and Cacajao calvus rubicundus (Ayres 1986).

Cacajao c. calvus has a restricted range, from the confluence of the rios Japurá and Solimões north-west between the two rivers connecting to either the Paraná Yaula, or the Furo or Paraná da Aranapa in Brazil (Hershkovitz 1987). Until recently, the White Bald-headed Uacari was considered endemic to Mamirauá Sustainable Development Reserve, but observations indicate the presence of this taxon in the region of the lower Juruá (Vira Volta), south of the Solimões (Silva Jr. pers. comm.). A new population of white uacaris was recorded from the Rio Jurupari, a tributary of the Rio Envira in the state of Amazons, about 750 km to south-west of the current range (Silva Jr. pers. comm.), and another sighting along the Alto Jurupari south of the town Feijó in the state of Acre (L. Veiga pers. comm.), but it has not yet been confirmed whether or not these are the same or distinct taxa (see Figueiredo 2006). Unlike most other Amazonian platyrrhines, uacaris tend to range along rivers rather than within interfluvia; várzea forests connect the two populations along the rivers between these two areas. No field data are available to determine if these populations are allopatric. The subspecies Cacajao c. novaesi occurs in the middle of these two populations (Silva, Jr. and Martins 1999).

The geographic range of Cacajao c. novaesi has been updated since first described by Hershkoivitz (1987) when it was thought to occur only on the south bank of the upper rio Juruá between the Rios Tarauacá and Eirú. Peres (1988, 1997) extended its range north-east of the range described by Hershkovitz (1987), on the left bank of the Juruá and at Lago da Fortuna, Carauari to the north. Populations of Cacajao calvus observed by Peres on the upper Juruá, and unconfirmed reports by Fernandes (1990) in the Brazilian state of Acre on the upper Juruá and Purus, are either of Cacajao calvus novaesi or Cacajao calvus ucayalii, which would extend the known ranges of either of these subspecies (Bowler 2007).

Cacajao c. rubicundus occurs in Brazil, with a relatively restricted (poorly known) range. It presents an apparent disjunct geographic distribution, known from an area situated in the Iça-Solimões interfluve in Amazonas (type locality: opposite the town of São Paulo de Olivença, north bank of the Solimões [Hershkovitz 1987]), and another near the mouth of the Auati-Paraná. Cacajao c. rubicundus also occurs south of the Solimões, west of the Jutaí River at the Jutaí-Solimões Ecological Station (Nogueira-Neto 1992). It may have formerly occurred in the Trapezium of Colombia, but if they did they are now believed to be extirpated.

Cacajao c. ucayalii is found south of the Amazon River in Peru between the Ucayali and Yavarí Rivers. In the past, its range probably extended as far as the Urubamba River (Hershkovitz 1987), but surveys undertaken in the 1980s suggest that the southern limit is now the Sheshea River (Aquino 1988). Hershkovitz (1987) claimed this taxon also occurs on the east bank of the lower Yavarí in Brazil. The subspecies has a patchy distribution. It may no longer be present on the Brazilian side of the Yavarí, and is absent from a long stretch on the Peruvian side, upriver from the mouth of the Yavarí-Mirín perhaps as far as Quebrada Curacinha close to the town of Colonia Angamos (Salovaara et al. 2003). On the Yavarí-Mirín, the species is present on a large of the North bank, but is absent from the south side of the river, except in the upper reaches. As noted earlier, populations of Cacajao calvus observed by Peres on the upper Juruá and unconfirmed reports by Fernandes (1990) in the Brazilian state of Acre on the upper Juruá and Purus, may be either of Cacajao calvus novaesi or Cacajao calvus ucayalii, which would extend the known ranges of either of these subspecies (Silva Jr.and Martins 1999).
Brazil; Peru
Possibly extinct:
Range Map:Click here to open the map viewer and explore range.

Population [top]

Population: Uacaris generally tend to occur at low densities.

Cacajao. c. calvus:
Average population densities in the region surrounding Mamirauá and Teiu Lakes (Mamirauá Reserve) were 10 individuals/km² (5 sites) in 1984/5 (Ayres 1986) and 17/km² (6 sites) in 2004/5 (Paim 2005).

Cacajao c. ucayalii:
In surveys undertaken in the Sierras de Contamana, part of the Sierra del Divisor located on the right margin of the Ucayali River, near the frontier with Brazil, this subspecies was recorded at an abundance of 479 individuals/100 km (Aquino 2005). Sites on the Yavarí and Yavarí-Mirín have some of the highest densities of (Puertas and Bodmer 1993; Salovaara et al. 2003). Jorge and Velazco (2006) discovered some new populations on the upper Tapiche River and on the Divisor ridges in the Zona Reservada Sierra del Divisor.
Population Trend: Decreasing

Habitat and Ecology [top]

Habitat and Ecology: Bald-headed Uacaris are habitat specialists that are limited primarily to white-water várzea habitats. In addition to their ecological range restrictions, their distribution along rivers makes them relatively more vulnerable to human impact. They are highly specialized seed predators, with immature seeds and fruits comprising the bulk of the diet. Uacaris live in large multi-male, multi-female groups with a fission-fusion social organization. Specialist habitat and feeding requirements may mean greater sensitivity to habitat modification. While other pitheciines (Chiropotes and Pithecia) have demonstrated a degree of tolerance and adaptability in the face of habitat disturbance, the capacity of uacaris to cope with anthropogenic disturbance is unknown.

Cacajao c. calvus:
This taxon is a habitat specialist that is primarily limited to flooded forests such as the lower Rio Juruá or the white-water várzea habitats of the low Rio Japurú. The White Bald-headed Uacari is a highly specialized seed predator, fruits and seeds are the most important food item and just a handful of tree species made up the bulk of the diet (Ayres 1986).

Cacajao c. rubicundus:
No field data on ecology are available for this subspecies.

Cacajao c. ucayalii:
Occurs in flooded forests, low to medium hill and high terrace forests, and palm swamps. As with other Bald Uacaris, Red Uacaris are specialized for the predation of seeds, with fruits and immature seeds making up the bulk of the diet. Mauritia flexuosa palm fruit was also the most important species in the diet of this taxon at Lago Preto, accounting for 20% of the annual diet (Bowler 2007).
Systems: Terrestrial

Threats [top]

Major Threat(s): The major threats to this species include forest loss and hunting. The distribution along rivers may make this taxon relatively more vulnerable to human impact, while specialist habitat and feeding requirements may result in greater sensitivity to habitat disturbance.

Cacajao c. calvus:
Although this subspecies is rarely hunted in its range because its appearance is considered too human-like (Ayres 1986), the main threat facing this primate is the reduction and transformation of its flooded forest habitat. The main forms of deforestation in the area, are small-scale agriculture and logging (Ayres and Johns 1987). Current data indicate that almost the entire (confirmed) population are included within the Mamirauá Sustainable Development Reserve and population densities appear to have increased in the 20 years up to 2005 (Ayres 1986; Paim 2005).

Cacajao c. rubicundus:
This species is hunted for food. It may be affected by habitat loss due to logging and forest loss especially along the main stream of the Amazon.

Cacajao c. ucayalii:
Surveys conducted between 1979 and 1986 (Aquino 1988) showed that the range was much reduced, hunting having exterminated the species in several areas. Aquino (1988) suggests that populations close to the Ucayali and Amazon Rivers have been greatly reduced and in some areas exterminated, caused by hunting and habitat disturbance. The Yavarí River and its tributary the Yaquerana represent the stronghold for remaining populations. Close to Iquitos, Mauritia flexuosa is extracted in large quantities by felling the palms (Bodmer et al. 1999; Meyer and Penn 2003); the unsustainable extraction of this resource may have an impact on Cacajao c. ucayalii in some areas (Bowler 2007). Logging concessions designated in 2004 cover around one-third of the geographic range of Cacajao c. ucayalii. While the selective removal of low-density, high-value timber species does not appear likely to have a great impact on populations of Cacajao c. ucayalii, the logging operations increase human populations and bushmeat hunting in remote parts of the range (Bowler 2007). Hunting levels on the Yavarí-Mirín and Yavarí have increased since 2004, when human populations increased due to logging activities. Bodmer et al. (2006) found that more wild meat was consumed per capita in a commercial forest concession on the Yavarí than in the nearby rural communities.

Cacajao c. novaesi:
This subspecies is affected to some degree by hunting and the exploitation of natural resources within the two extractive reserves where it occurs.

Conservation Actions [top]

Conservation Actions: This species is listed on CITES Appendix I. The Primate Protection Centre (Centro de Proteção de Primatas Brasileiros: ICM/CPB ), of the Federal Environmental Protection Institute (Instituto Chico Mendes), supports and coordinates primate conservation programmes throughout Brazil. An international committee (Comitê Internacional para Conservação e Manejo dos Primatas Amazônicos) was established by the the CPB and Instituto Chico Mendes (ICM) to discuss and define actions for the conservation of Amazonian primate taxa, and together with the members of the Pitheciine Action Group (PAG), is currently developing Conservation Action Plans for each of the four subspecies in Brazil.

A decree (No. 34-2004-AG) was published by the Peruvian government in 2004 that approves the categorization of threatened Peruvian wildlife and prohibits hunting, capturing, owning, transporting, and exportation for commercial purposes. It is hoped that this will help in conservation actions and stimulate research on threatened Peruvian wildlife (Heymann 2004).

Cacajao c. calvus:
This subspecies is protected within the Mamirauá Sustainable Development Reserve (Ayres et al. 1999).

Cacajao c. novaesi:
Afforded some protection within two extractive reserves, the Middle Juruá and the Upper Juruá, where hunting and the exploitation of natural resources are permitted.

Cacajao c. rubicundus:
Cacajao c. rubicundus should be relatively well protected as it occurs within the Jutaí-Solimões Ecological Station (284,285 ha), south of the rio Solimões (Nogueira-Neto 1992).

Cacjao c. ucayalii:
Until recently, the only protected area known to contain Cacajao calvus ucayalii was the regional Tamshiyacu Tahuayo Communal Reserve (TTCR). The TTCR extends over an area of 322,500 ha, and is situated close to the city of Iquitos in upland forests between the Amazon and the Yavarí (Newing and Bodmer 2004). The reserve was created as a result of a strong alliance between local people and conservationists. The presence of Cacajao calvus ucayalii has become part of the justification for three areas either under proposal or newly created. These are the Sierra del Divisor Reserved Zone, the Lago Preto Conservation Concession (LPCC) and the proposed Greater Yavarí Reserve. Community conservation work is conducted by WCS-Peru and the Durrell Institute of Conservation and Ecology on the Yavari and Yavari-Mirin Rivers in Peru. This project aims to reduce the hunting of Cacajao c. ucayalii in this area (Bowler 2007).

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Citation: Veiga, L.M., Bowler, M., Silva Jr., J.S., Queiroz, H.L., Boubli, J.-P. & Rylands, A.B. 2008. Cacajao calvus. In: IUCN 2013. IUCN Red List of Threatened Species. Version 2013.2. <>. Downloaded on 17 April 2014.
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