Brachyteles arachnoides


Taxonomy [top]

Kingdom Phylum Class Order Family

Scientific Name: Brachyteles arachnoides
Species Authority: (É. Geoffroy, 1806)
Common Name(s):
English Muriqui, Southern Muriqui, Woolly Spider Monkey
French Atèle Arachnoïde, Eroïde, Singe-araignée Laineux
Spanish Mono Carvoeiro, Mono Grande, Muriki
Taxonomic Notes: Vieira (1944) recognized two subspecies of Brachyteles. Recent evidence provided by Lemos de Sá et al. (1990), Fonseca et al. (1991) and Lemos de Sá and Glander (1993) indicated that Vieira’s original (1944) standing was valid, but that differentiation is even more extreme and justifies the classification of the two forms as separate species (see also Coimbra-Filho et al. 1993). Groves (2001, 2005) lists the two muriquis as separate species.

Assessment Information [top]

Red List Category & Criteria: Endangered C1 ver 3.1
Year Published: 2008
Date Assessed: 2008-06-30
Assessor(s): Mendes, S.L., de Oliveira, M.M., Mittermeier, R.A. & Rylands, A.B.
Reviewer(s): Mittermeier, R.A., Rylands, A.B. (Primate Red List Authority) & Hoffmann, M. (Global Mammal Assessment Team)
This species is listed as Endangered due to a small population as well as historic and ongoing decline due primarily to hunting pressure. There are less than 1,500 individuals left in the wild, and it is entirely feasible that the population could undergo a 20% decline over the course of the coming two generations (estimated at 40 years). Historic loss of habitat has fragmented populations across part of the range. It is also entirely possible that this species has suffered a decline exceeding 80% over the course of the past 60 years, thereby potentially qualifying for listing under criterion A.
2003 Endangered
2000 Critically Endangered
1996 Endangered

Geographic Range [top]

Range Description: According to Aguirre (1971), Brachyteles arachnoides was to be found in climax montane forests at altitudes of 600 to 1,800 m above sea level, in well-preserved remnants of seasonal and evergreen forests in the states of São Paulo, Rio de Janeiro and Paraná. It occurs north as far as the southern slopes of the Serra da Mantiqueira, running approximately east-west in southern Minas Gerais, northern São Paulo and Rio de Janeiro (Lemos de Sá and Glander 1993). Its stronghold today is in the montane forests of the Serra de Paranapiacaba (Talebi and Soares 2005). Based on a reference of Krieg, cited by Hill (1962, pp.252–356), Aguirre (1971) considered the southern limit of the range of the species to be about 25ºS, in the region of the Rio Ribeira in Paraná. Martuscelli et al. (1994) informed of two localities where they found muriquis in Paraná. One was in the municipality of Jaguariaíva, the other in the Guaraqueçaba Environmental Protection Area, near to 25ºS, corroborating the southern limit of Aguirre (1971). The first locality is in the municipality of Sengés, on the banks of the Rio Jaguaricatu, and the second is in the south of the state of São Paulo (Koehler et al. 2005).

Koehler et al. (2005) provide details of its known range on northern Paraná. These authors carried out surveys for B. arachnoides along the rios Açungui, Ribeira, Turvo, Santana and Ponta Grossa and, farther east, on the rios Grande and São Sebastião (all affluents of the Rio Ribeira marking the state limits of Paraná with São Paulo). Throughout the region, the only remnant forest of any considerable size is that of the Lauráceas State Park of 23,000 ha, in a montane region of the municipalities of Adrianópolis and Tunas do Paraná. It is quite probable that muriquis will be found there.
Brazil (Paraná, Rio de Janeiro, São Paulo)
Range Map: Click here to open the map viewer and explore range.

Population [top]

Population: The estimated total population is 1,300 individuals (Melo and Dias 2005). The largest single population of muriquis is evidently that in the Carlos Botelho State Park.
Population Trend: Decreasing

Habitat and Ecology [top]

Habitat and Ecology: Inhabits submontane and montane evergreen tropical forest of the Atlantic coast of Brazil.

Studies of feeding ecology have been made in the Carlos Botelho State Park (Moraes 1992a,b; Talebi et al. 2005), the Fazenda Barreiro Rico by Milton (1984) and Martins (2003a,b, 2005b, 2006) and the Intervales State Park (Petroni 1993, 2000).

Adult male weight 10.2 kg (n=1) (Lemos de Sá and Glander 1993)
Adult female weight 8.5 kg (n=1) (Lemos de Sá and Glander 1993)
Systems: Terrestrial

Threats [top]

Major Threat(s): The geographical distribution and status of the southern muriqui populations in São Paulo are still poorly known. Hunting (Lane 1990) and habitat loss and fragmentation are the main threats. The southern muriqui has been extirpated throughout the lowland (plateau) forests of São Paulo, Paraná and Rio de Janeiro, except at one site: the Fazenda Barreiro Rico in Sao Paulo (Milton and de Lucca 1984; Martins 2005b). Today, its populations can only otherwise be found in remote montane forests of the Serra do Mar in Rio de Janeiro and São Paulo. Although occurring in relatively large expanses of protected forest, it seems they occur naturally at lower densities in these areas than in smaller, fragmented forests. All wild muriqui populations are declining.

The following are the current principal threats to the southern muriqui as outlined by Talebi and Soares (2005):

Forest loss. Less than 7% of the muriqui’s forests remain, and much of what does is highly fragmented. Deforestation has occurred as a result of logging, intensive land-use for subsistence and commercial farming (for example, coffee), timber plantations (eucalyptus and pine) and cattle ranching, through urban expansion, and highway construction and general infrastructure development, both regional and national, such as dams and the leisure industry. Despite its protected status, the Paranapiacaba Ecological Continuum will always be under threat from developmental pressures such as these.

Hunting for sport. Historically, and even today in some areas, the muriqui is hunted for sport, a cultural trait that has remained from the earliest days of the colonization of São Paulo State by Europeans.

Mining in the buffer zones of protected areas. This refers particularly to bauxite, sand, clay, and granite. These activities result in deforestation, erosion, flooding, and the silting and pollution of rivers and streams.

Illegal palm-harvesting in large areas of forest. The palm tree, Euterpe edulis, is endemic to the Atlantic Forest, and an economically important forest product. Palm tree harvesters (palmiteiros) camp in the forest and transport and process the palm hearts in glass jars, while still in the forest. Thousands of palm trees can be felled in just a few days. Populations of E. edulis are declining everywhere in areas where they used to be the dominant understorey tree. Palmiteiros hunt game, including muriquis, during their sojourns in the forest.

Most of these threats are repeated by Garcia (2005), who summarizes threats to this species in Rio de Janeiro as follows:

Although occurring in a number of protected areas, muriquis are under pressure from hunting, habitat loss and degradation, and disturbance from human activities everywhere they occur. In the Serra dos Órgãos National Park, for example, both adventure tourism (perhaps restricting the area that the muriquis will use) and hunting were evidently serious enough to be prejudicial to the small number of muriquis surviving there (Cunha 2005). There is hunting throughout the park. In the APA Cairuçú, the Paraíso Ecological Station, and in the region of Macaé de Cima hunting is also the key factor (Silva 1987; Martuscelli et al. 1994). Garcia (2005) found that both hunting and deforestation by squatters are threats in the Desengano State Park. The Itatiaia National Park would seem to be comparatively free of hunting, and habitat loss is probably the key issue with the constant presence of people living in the park, of tourists, the threat of fires, and the illegal exploitation of plants such as palms for palm hearts (Rocha et al. 2003).

Conservation Actions [top]

Conservation Actions: This species is recorded from the following protected areas:

Itatiaia National Park, Rio de Janeiro (28,267 ha) (Câmara 1995; Marroig and Sant`Anna 2001)
Serra dos Órgãos National Park, Rio de Janeiro (11,800 ha) (Garcia and Andrade Filho 2002; Cunha 2003, 2004)
Desengano State Park, Rio de Janeiro (22,400 ha) (Garcia 2005)
Carlos Botelho State Park, São Paulo (37,432 ha) (Pacaganella 1991; Mittermeier et al. 1987; Talebi and Soares 2005)
Intervales State Park, São Paulo (45,000 ha) (Petroni 2000)
Alto Ribeira State Park (55,000 ha) (UNESCO 1999)
Lauráceas State Park, Paraná (23,000 ha) (possibly: Koehler et al. 2005)
Xitué Ecological Station (3,095 ha) (Gonzalez-Solis et al. 2001)
Paraiso Ecological Station, Rio de Janeiro (5,000 ha) (Garcia 2005)
Cairuçú Environmetal Protection Area (APA), Rio de Janeiro (33,800 ha) (Vaz 1998; Garcia 2005)
Guaraqueçaba Environmental Protection Area, Paraná (283,014 ha) (Martuscelli et al. 1994; Koehler et al. 2005

A long-term research site was set up in the Carlos Botelho State Park in 1986 and the NGO Associação Pró-Muriqui was set up in 2000 to ensure continued research activities in the park and elsewhere in São Paulo (Talebi and Soares 2005)

A Population and Habitat Viability Analysis (PHVA) was held for both species of Brachyteles in 1998 (Rylands et al. 1998), which sparked a series of surveys in Minas Gerais, Rio de Janeiro, Espírito Santo and Bahia. In 2002, the Brazilian Institute for the Environment (IBAMA) set up the Committee for the Conservation and Management of the Muriqui (Oliveira et al. 2005).

There is a small, but promising, captive breeding programme for the species (Coimbra- Filho et al. 1993; Pissinatti et al. 1998; Pissinatti 2005). Captive breeding has been problematic due to low levels of reproduction and poor infant survival. Some zoos in São Paulo (for example, Sorocaba and Santos) receive wild-born muriqui pets every year, originating mostly from palm-harvesters and hunters who have killed the mother. Investment in a well-managed breeding programme helps greatly enhance our understanding of the primates and provides a backstop for population extinctions in the wild.

This species is listed on Appendix I of CITES.

Citation: Mendes, S.L., de Oliveira, M.M., Mittermeier, R.A. & Rylands, A.B. 2008. Brachyteles arachnoides. The IUCN Red List of Threatened Species. Version 2015.2. <>. Downloaded on 04 July 2015.
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