The Peruvian spider monkey (''Ateles chamek''), also known as the black-faced black spider monkey, is a species of

spider monkey Spider monkeys are New World monkeys belonging to the genus ''Ateles'', part of the subfamily Atelinae, family Atelidae. Like other atelines, they are found in tropical forests of Central and South America, from southern Mexico to Brazil. The g ...

that lives in

Peru , image_flag = Flag of Peru.svg , image_coat = Escudo nacional del Perú.svg , other_symbol = Great Seal of the State , other_symbol_type = Seal (emblem), National seal , national_motto = "Fi ...

, as well as in

Brazil Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...

and in

Bolivia , image_flag = Bandera de Bolivia (Estado).svg , flag_alt = Horizontal tricolor (red, yellow, and green from top to bottom) with the coat of arms of Bolivia in the center , flag_alt2 = 7 × 7 square p ...

. At long, they are relatively large among species of monkey, and their strong, prehensile tails can be up to long. Unlike many species of monkey, they have only a

vestigial Vestigiality is the retention, during the process of evolution, of genetically determined structures or attributes that have lost some or all of the ancestral function in a given species. Assessment of the vestigiality must generally rely on co ...

thumb, an adaptation which enables them to travel using brachiation. Peruvian spider monkeys live in groups of 20–30 individuals, but these groups are rarely all together simultaneously. The size and dynamics of the resulting subgroups vary with food availability and sociobehavioral activity. They prefer to eat fleshy fruit, but will change their diet in response to scarcity of ripe fruit. Individuals of this species also eat small animals, insects and leaves based on availability. Females separate from the band to give birth, typically in the fall. These females inhabit a group of core areas where resources are abundant in certain seasons. Typically, males exhibit ranging over longer distances than females, with movement of individuals enhancing the fluidity of subgroup size. Peruvian spider monkey are independent at about 10 months, with a lifespan of about 20 years.

Characteristics

The Peruvian spider monkey weighs up to . Its body can be long and the tail can be long. It has four elongated fingers and virtually no thumb, which is typical for spider monkeys but unusual for other monkeys. It can move easily through the trees and it has a prehensile tail like other species in the genus ''Ateles'', which it uses to assist with

brachiation Brachiation (from "brachium", Latin for "arm"), or arm swinging, is a form of arboreal locomotion in which primates swing from tree limb to tree limb using only their arms. During brachiation, the body is alternately supported under each forelimb ...

. It has an agility that can only be compared to the

gibbon Gibbons () are apes in the family Hylobatidae (). The family historically contained one genus, but now is split into four extant genera and 20 species. Gibbons live in subtropical and tropical rainforest from eastern Bangladesh to Northeast India ...

of Asia. It has a life span of up to 20 years.Spider Monkeys, Great Book of the Animal Kingdom, Crescent Books, Inc., pp. 378-379

Distribution

The species occurs in central-northern of Bolivia, north-eastern Peru, and the central-western Brazilian Amazon. The species was recently found to occur in the northern bank of Solimões River, at the Mamirauá Reserve, where it probably colonized through a river

meander cutoff A meander cutoff is a natural form of a cutting or cut in a river occurs when a pronounced meander (hook) in a river is breached by a flow that connects the two closest parts of the hook to form a new channel, a full loop. The steeper drop in grad ...

process. They live primarily in lowland forests, occupying the canopy and the sub-canopy, but they have been observed using various habitat types, including dry and hilly areas such as the piedmont and cerrado forests, and have been observed to move depending on food availability. They were also observed living in Amazonian seasonally flooded forests. They live in territorial bands of 6–12 individuals whose territory covers about 20 square kilometers. Band size is somewhat seasonal, probably because females separate themselves from the band for a few months to give birth, primarily in the fall. It has to contest with other spider monkeys,

woolly monkey The woolly monkeys are the genus ''Lagothrix'' of New World monkeys, usually placed in the family Atelidae. Both species in this genus originate from the rainforests of South America. They have prehensile tails and live in relatively large soci ...

s, and

howler monkey Howler monkeys (genus ''Alouatta'', monotypic in subfamily Alouattinae) are the most widespread primate genus in the Neotropics and are among the largest of the platyrrhines along with the muriquis (''Brachyteles''), the spider monkeys (''Ateles' ...

s for food and territory.

Food

The Peruvian spider monkey feeds on leaves, berries, small animals such as birds and frogs, flowers, termites, honey, grubs, and fruits. It is primarily

frugivorous A frugivore is an animal that thrives mostly on raw fruits or succulent fruit-like produce of plants such as roots, shoots, nuts and seeds. Approximately 20% of mammalian herbivores eat fruit. Frugivores are highly dependent on the abundance and ...

with a tendency to exhibit

folivory In zoology, a folivore is a herbivore that specializes in eating leaves. Mature leaves contain a high proportion of hard-to-digest cellulose, less energy than other types of foods, and often toxic compounds.Jones, S., Martin, R., & Pilbeam, D. (1 ...

in times of fruit scarcity. It will also eat insects, baby birds, bird eggs, and frogs. In the Amazon, groups of Peruvian spider monkeys show strong seasonal variations in habitat based on the availability of fleshy fruits. The foraging habits of this species causes the monkeys to be a vital component of

seed dispersal In Spermatophyte plants, seed dispersal is the movement, spread or transport of seeds away from the parent plant. Plants have limited mobility and rely upon a variety of dispersal vectors to transport their seeds, including both abiotic vectors, ...

patterns for many tree species in Amazonia.

Growth and reproduction

The spider monkey has a reproductive period that can span throughout the year, though most offspring are born at the start of the

Autumn Autumn, also known as fall in American English and Canadian English, is one of the four temperate seasons on Earth. Outside the tropics, autumn marks the transition from summer to winter, in September ( Northern Hemisphere) or March ( Sou ...

season. It has a gestation period of about 140 days. The pregnant female leaves the group to have her baby and returns 2–4 months later. The newborn spider monkey is independent at about 10 months.

Conservation status

This species of spider monkey, in addition to other species within the genus ''Ateles'', is threatened due to exploitation by humans and habitat loss. It is currently listed on the

IUCN Red List of Threatened Species 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 the world's most comprehensive inventory of the global conservation status of biologi ...

as Endangered and is listed in Appendix II of

CITES CITES (shorter name for the Convention on International Trade in Endangered Species of Wild Fauna and Flora, also known as the Washington Convention) is a multilateral treaty to protect endangered plants and animals from the threats of interna ...

despite having been listed as a species of "Least concern" in 2003. The IUCN experts claim that the number of individuals has declined by at least 50% over the past 45 years. Researchers suggest that the species may effectively occupy only 28% of its entire range, and that only 32% of the species’ area of occupancy is legally protected. They also suggests that 31–40% of the species’ habitat will be lost by 2050. This decline is partially due to the fact that these monkeys are targeted by hunters for sale and consumption in the Amazonian

bushmeat Bushmeat is meat from wildlife species that are hunted for human consumption, most often referring to the meat of game in Africa. Bushmeat represents a primary source of animal protein and a cash-earning commodity for inhabitants of humid tropi ...

trade. Furthermore, habitat in the southern part of its range is being developed for agriculture and habitat in the southwestern Peruvian region of Madre de Dios is being polluted and destroyed by illegal mining activity. In Peru, illicit extraction of timber and wildlife products remain issues even in protected areas. Studies show that in heavily hunted and farmed areas, large-bodied primate species such as spider monkeys are likely to be some of the first species to be

extirpated Local extinction, also known as extirpation, refers to a species (or other taxon) of plant or animal that ceases to exist in a chosen geographic area of study, though it still exists elsewhere. Local extinctions are contrasted with global extinct ...

. Reintroduction efforts by researchers at

Reserva Ecologica Taricaya Reserva Ecologica Taricaya is a private nature reserve located in the Peruvian Amazon along the Madre de Dios River, a major tributary to the Amazon River. Since 2004, it has been under the ownership of Projects Abroad, a for-profit company based ...

have begun along the lower Madre de Dios river where conservation efforts now provide a suitable release site and protected habitat.

Similar or related species

In addition to external appearance, the Peruvian spider monkey differs from the

red-faced spider monkey The red-faced spider monkey (''Ateles paniscus'') also known as the Guiana spider monkey or red-faced black spider monkey, is a species of spider monkey found in the rain forests in northern South America. The species faces issues with hunting a ...

by the number of

chromosome A chromosome is a long DNA molecule with part or all of the genetic material of an organism. In most chromosomes the very long thin DNA fibers are coated with packaging proteins; in eukaryotic cells the most important of these proteins are ...

s ( 2n = 32 in the red-faced vs. 2n = 34 in the Peruvian) in addition to several specific chromosomal differences. The two species have been interbred in captivity, resulting in offspring with reduced fertility (but not sterility). There are several related species such as the Central American spider monkey or Geoffroy's spider monkey (''A. geoffroyi''), and the

brown spider monkey The brown spider monkey or variegated spider monkey (''Ateles hybridus'') is a critically endangered species of spider monkey, a type of New World monkey, from forests in northern Colombia and northwestern Venezuela. Like all spider monkeys, it ...

(''A. hybridus'') and the species' closest relative the

white-bellied spider monkey The white-bellied spider monkey (''Ateles belzebuth''), also known as the white-fronted or long-haired spider monkey, is an Endangered species, endangered species of spider monkey, a type of New World monkey. It is found in the north-western Amaz ...

(''A. belzebuth''). All of these have a prehensile tail, a thumbless hand, and other characteristics that are found in all spider monkeys.Spider Monkey, Animal The Definitive Visual Guide to the World’s Wildlife, p. 123; Spider Monkeys, Great Book of the Animal Kingdom, Crescent Books, Inc., pp. 378-379

References

{{Taxonbar, from=Q280520 Spider monkeys Mammals of Brazil Mammals of Peru Mammals of Bolivia Mammals described in 1812 Primates of South America Taxa named by Alexander von Humboldt