Northern Muriqui, Brachyteles hypoxanthus

Northern Muriqui
Brachyteles hypoxanthus (Kuhl, 1820)
Brazil
(2000, 2002, 2004)
Once widespread in southeastern Brazil, the largest of South America's primates now barely survives in the scattered remnants of the Atlantic Forest.

The two muriqui species (Brachyteles hypoxanthus and the southern muriqui, B. arachnoides) are the largest primates in South America and both are endemic to Brazil's Atlantic Forest region. They live in multi-male groups which can reach more than 50 animals, and were once widespread through the forests of south-east Brazil, from the northern part of the state of Paraná, through São Paulo, Rio de Janeiro, and Espírito Santo to coastal Bahia. Both have suffered from hunting and the destruction of their forests since the 16th century.
The northern muriqui, occurring in Minas Gerais, Espírito Santo and Bahia, is the more threatened of the two, its numbers being lower and its populations smaller and more fragmented than those of the southern muriqui which, although also endangered, has benefited from refuge in the relatively intact and inaccessible forests of the Serra do Mar in Rio de Janeiro and São Paulo.

The largest known population of the northern muriqui today is in the forests of the Caratinga Biological Station, an 890-ha private reserve in the state of Minas Gerais (in 2004 numbering approximately 225 individuals). Karen Strier (University of Wisconsin-Madison) has led a research program there since 1983, which has provided invaluable insights into their demography, ecology and behavior. A second major field site is now being set up in Santa Maria de Jetibá, Espírito Santo, by Sérgio Mendes and his colleagues from the state's federal university.

Recent surveys in the Rio Doce State Park (Minas Gerais) and the Caparaó National Park (on the border of Minas Gerais and Espírito Santo) are indicating the occurrence of populations which may be as large as, or even larger than, those at Caratinga. Besides the Caparaó National Park and the Augusto Ruschi Biological Reserve, surveys over the last few years have located northern muriquis in 12 localities in the municipality of Santa Maria de Jetibá in Espírito Santo. The Serra do Brigadeiro State Park (Minas Gerais) also protects a significant population, estimated at more than 100 animals.

Groups have also been found in two forests in north-eastern Minas Gerais by teams from the Minas Gerais State Forestry Institute. One was rapidly turned into a large federal protected area, the Mata Escura Biological Reserve, and the other, extending across the border into Bahia (Alto Cariri), is currently under study for the creation of a protected area as well. These are the northernmost localities where the species is known to survive today.

In 2001, a survey by a team from the Federal University of Minas Gerais also confirmed the survival of a small population of at least 13 in the Fazenda Córrego de Areia, municipality of Peçanha, eastern Minas Gerais, and they also occur in the Ibitipoca State Park in the south. The total known population today is estimated at between 700 and 1000 animals.

Karen B. Strier, Sérgio L. Mendes, Jean Philippe Boubli & Luiz G. Dias

References
Strier, K. B. 1999. Faces in the Forest: The Endangered Muriqui Monkeys of Brazil. Harvard University Press, Cambridge, MA.
Strier, K. B. 2000. Population viability and regional conservation priorities for muriquis (Brachyteles arachnoides) in Brazil's Atlantic forest. Biotropica 32: 903-913.
Strier, K. B. and Fonseca, G. A. B. da. 1996/1997. The endangered muriqui in Brazil's Atlantic forest. Primate Conservation (17): 131-137.
Strier, K. B., Boubli, J. P., Guimarães, V. O. and Mendes, S. L. 2002. The muriqui population at the Estação Biológica de Caratinga, Minas Gerais, Brazil: Updates. Neotropical Primates 10(3): 115-199.

Suggested citation:
Strier, K. B., Mendes, S. L., Boubli, J.-P. and Dias, L. G. 2005. Northern Muriqui, Brachyteles hypoxanthus (Kuhl, 1820). In: Primates in Peril: The World's 25 Most Endangered Primates 2004-2006, R. A. Mittermeier, C. Valladares-P�dua, A. B. Rylands, A. A. Eudey, T. M. Butynski, J. U. Ganzhorn, R. Kormos, J. M. Aguiar and S. Walker (eds.), p.24. Report to IUCN/SSC Primate Specialist Group (PSG), International Primatological Society (IPS) and Conservation International (CI), Washington, DC.