Rylands' bald-faced saki (''Pithecia rylandsi'') is a disputed species of saki monkey, a type of

New World monkey New World monkeys are the five families of primates that are found in the tropical regions of Mexico, Central and South America: Callitrichidae, Cebidae, Aotidae, Pitheciidae, and Atelidae. The five families are ranked together as the Ceboi ...

. It is found in

Bolivia Bolivia, officially the Plurinational State of Bolivia, is a landlocked country located in central South America. The country features diverse geography, including vast Amazonian plains, tropical lowlands, mountains, the Gran Chaco Province, w ...

Peru Peru, officially the Republic of Peru, is a country in western South America. It is bordered in the north by Ecuador and Colombia, in the east by Brazil, in the southeast by Bolivia, in the south by Chile, and in the south and west by the Pac ...

, and

Brazil Brazil, officially the Federative Republic of Brazil, is the largest country in South America. It is the world's List of countries and dependencies by area, fifth-largest country by area and the List of countries and dependencies by population ...

Taxonomy

Populations in this species were formerly classified within the

Rio Tapajós saki The Rio Tapajós saki or Gray's bald-faced saki (''Pithecia irrorata'') is a species of saki monkey, a type of New World monkey, from South America. It is found in parts of western Brazil, southeastern Colombia, southeastern Peru and possibly no ...

(''P. irrorata''), but a 2014 study described these populations as a distinct species, ''P. rylandsi'', based on their distinctive

pelage A fur is a soft, thick growth of hair that covers the skin of almost all mammals. It consists of a combination of oily guard hair on top and thick underfur beneath. The guard hair keeps moisture from reaching the skin; the underfur acts as an ...

. However, a 2019 study, also analyzing pelage color variation across the range of the ''P. irrorata''

species complex In biology, a species complex is a group of closely related organisms that are so similar in appearance and other features that the boundaries between them are often unclear. The taxa in the complex may be able to hybridize readily with each oth ...

, delineated only two distinctive groups corresponding to ''P. irrorata'' and Vanzolini's bald-faced saki (''P. vanzolini''), with the distinctive pelage used to distinguish ''P. rylandsi'' falling within the range of variation of ''P. irrorata''. In addition, the study found that due to an unclear type locality, the holotype of ''P. irrorata'' may have been collected within the range of ''P. rylandsi'', which would render ''rylandsi'' instantly synonymous with ''P. irrorata''. Based on this study, the

American Society of Mammalogists The American Society of Mammalogists (ASM) was founded in 1919. Its primary purpose is to encourage the study of mammal A mammal () is a vertebrate animal of the Class (biology), class Mammalia (). Mammals are characterised by the presence ...

(tentatively, pending further phylogenetic studies) synonymized ''rylandsi'' with ''irrorata'', but the

IUCN Red List The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is an inventory of the global conservation status and extinction risk of biological ...

and

ITIS The Integrated Taxonomic Information System (ITIS) is an American partnership of federal agencies designed to provide consistent and reliable information on the taxonomy of biological species. ITIS was originally formed in 1996 as an interagenc ...

retain ''rylandsi'' as a distinct species. This species is named after Brazilian primatologist Anthony Rylands, a senior research scientist at

Conservation International Conservation International (CI) is an American nonprofit environmental organization headquartered in Crystal City, Virginia, in Arlington County, Virginia. CI's work focuses on science, policy and partnership with businesses, governments and co ...

, deputy chair of the IUCN/SSC Primate Specialist Group, member of the

Brazilian Academy of Sciences Brazilian commonly refers to: * Brazil, a country * Brazilians, its people * Brazilian Portuguese, its dialect Brazilian may also refer to: * "The Brazilian", a 1986 instrumental music piece by Genesis * Brazilian Café, Baghdad, Iraq (1937) * Bra ...

, a former Vertebrate Zoology professor at the

Federal University of Minas Gerais The Federal University of Minas Gerais (, UFMG) is a federalIn the Brazilian Higher Education context, ''Federal'' does not mean ''collegiate'' (even though most Federal Universities in Brazil enjoy a similarly collegiate system), but it means ...

, and founding editor for the journal ''Neotropical Primates''.

Distribution

This species is found in northwestern

, southeastern

, and southern

Rondônia Rondônia () is one of the 26 states of Brazil, located in the northern subdivision of the country (central-western part). It is bordered by Acre (state), Acre in the west, Amazonas, Brazil, Amazonas in the north, Mato Grosso in the east, and Bo ...

& western

Mato Grosso Mato Grosso ( – ) is one of the states of Brazil, the List of Brazilian states by area, third largest by area, located in the Central-West Region, Brazil, Central-West region. The state has 1.66% of the Brazilian population and is responsible ...

. It is found north of the

Madre de Dios River The Madre de Dios River () is a river shared by Bolivia and Peru which is homonymous to the Peruvian region it runs through. On Bolivian territory, it receives the Beni River, close to the town of Riberalta, which later joins with the Mamore Riv ...

in Bolivia and Peru, and east & north of the Guaporé River in Brazil. It may range as far north as the Ji-Paraná River or west to the

Jamari River The Jamari River is a river of Rondônia state in western Brazil. Part of the river's watershed is covered by the Jacundá National Forest, a sustainable use conservation unit. The Jamari river is dammed by the Samuel Hydroelectric Dam near Po ...

Description

It is one of the largest of the sakis. This species is easily distinguishable from all other sakis by its very large size, very black, bare face, and the extreme white grizzling, which can often cause older males to look almost entirely white. Younger males are black in color with moderate grizzling. Adult females are almost as intensely white as males, and their hair on the forehead can form white "

bangs Bang, bang!, or bangs may refer to: Products * M1922 Bang rifle, a US semi-automatic rifle designed by Søren Hansen Bang * Bang, a List of model car brands, model car brand * Bang (beverage), an energy drink Geography * Bang, Central African ...

Status

This species is thought to be threatened by

deforestation Deforestation or forest clearance is the removal and destruction of a forest or stand of trees from land that is then converted to non-forest use. Deforestation can involve conversion of forest land to farms, ranches, or urban use. Ab ...

for

cattle ranching A ranch (from /Mexican Spanish) is an area of land, including various structures, given primarily to ranching, the practice of raising grazing livestock such as cattle and sheep. It is a subtype of farm. These terms are most often applied to li ...

, as well as

poaching Poaching is the illegal hunting or capturing of wild animals, usually associated with land use rights. Poaching was once performed by impoverished peasants for subsistence purposes and to supplement meager diets. It was set against the huntin ...

, and thus its population is thought to be declining. They are sometimes also found in the pet trade. It is thus classified as Vulnerable by the

References

{{Taxonbar, from=Q21306286 Rylands' bald-faced saki Primates of Brazil Mammals of Bolivia Mammals of Peru Rylands' bald-faced saki Controversial mammal taxa