|Black-headed spider monkey (Ateles fusciceps)|
E. Geoffroy, 1806
| Simia paniscus |
|Range of the spider monkeys|
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 genus contains seven species, all of which are under threat; the black-headed spider monkey and brown spider monkey are critically endangered.
New World monkeys are the five families of primates that are found in the tropical regions of Central and South America and Mexico: Callitrichidae, Cebidae, Aotidae, Pitheciidae, and Atelidae. The five families are ranked together as the Ceboidea, the only extant superfamily in the parvorder Platyrrhini. Platyrrhini means flat-nosed, and their noses are flatter than those of other simians, with sideways-facing nostrils. Monkeys in the family Atelidae, such as the spider monkey, are the only primates to have prehensile tails. New World monkeys' closest relatives are the other simians, the Catarrhini. New World monkeys descend from African simians that colonized South America, a line that split off about 40 million years ago.
A genus is a taxonomic rank used in the biological classification of living and fossil organisms, as well as viruses, in biology. In the hierarchy of biological classification, genus comes above species and below family. In binomial nomenclature, the genus name forms the first part of the binomial species name for each species within the genus.
The Atelinae are a subfamily of New World monkeys in the family Atelidae, and includes the various spider and woolly monkeys. The primary distinguishing feature of the atelines is their long prehensile tails, which can support their entire body weight.
Disproportionately long limbs and long prehensile tails make them one of the largest New World monkeys and give rise to their common name. Spider monkeys live in the upper layers of the rainforest, and forage in the high canopy, from 25 to 30 m (82 to 98 ft). They primarily eat fruits, but will also occasionally consume leaves, flowers, and insects. Due to their large size, spider monkeys require large tracts of moist evergreen forests, and prefer undisturbed primary rainforest. They are social animals and live in bands of up to 35 individuals but will split up to forage during the day.
A prehensile tail is the tail of an animal that has adapted to be able to grasp or hold objects. Fully prehensile tails can be used to hold and manipulate objects, and in particular to aid arboreal creatures in finding and eating food in the trees. If the tail cannot be used for this it is considered only partially prehensile - such tails are often used to anchor an animal's body to dangle from a branch, or as an aid for climbing. The term prehensile means "able to grasp".
Forage is a plant material eaten by grazing livestock. Historically, the term forage has meant only plants eaten by the animals directly as pasture, crop residue, or immature cereal crops, but it is also used more loosely to include similar plants cut for fodder and carried to the animals, especially as hay or silage. The term forage fish refers to small schooling fish that are preyed on by larger aquatic animals.
Recent meta-analyses on primate cognition studies indicated spider monkeys are the most intelligent New World monkeys.They can produce a wide range of sounds and will "bark" when threatened; other vocalisations include a whinny similar to a horse and prolonged screams.
A meta-analysis is a statistical analysis that combines the results of multiple scientific studies.
Primate cognition is the study of the intellectual and behavioral skills of non-human primates, particularly in the fields of psychology, behavioral biology, primatology, and anthropology.
They are an important food source due to their large size, so are widely hunted by local human populations; they are also threatened by habitat destruction due to logging and land clearing.Spider monkeys are susceptible to malaria and are used in laboratory studies of the disease. The population trend for spider monkeys is decreasing; the IUCN Red List lists one species as vulnerable, four species as endangered and two species as critically endangered.
Habitat destruction is the process by which natural habitat becomes incapable of supporting its native species. In this process, the organisms that previously used the site are displaced or destroyed, reducing biodiversity. Habitat destruction by human activity is mainly for the purpose of harvesting natural resources for industrial production and urbanization. Clearing habitats for agriculture is the principal cause of habitat destruction. Other important causes of habitat destruction include mining, logging, trawling, and urban sprawl. Habitat destruction is currently ranked as the primary cause of species extinction worldwide. It is a process of natural environmental change that may be caused by habitat fragmentation, geological processes, climate change or by human activities such as the introduction of invasive species, ecosystem nutrient depletion, and other human activities.
The IUCN Red List of Threatened Species, founded in 1965, has evolved to become the world's most comprehensive inventory of the global conservation status of biological species. It uses a set of criteria to evaluate the extinction risk of thousands of species and subspecies. These criteria are relevant to all species and all regions of the world, With its strong scientific base, the IUCN Red List is recognized as the most authoritative guide to the status of biological diversity. A series of Regional Red List are produced by countries or organizations, which assess the risk of extinction to species within a political management unit.
A vulnerable species is one which has been categorized by the International Union for Conservation of Nature as likely to become endangered unless the circumstances that are threatening its survival and reproduction improve.
Theories abound about the evolution of the atelines; one theory is they are most closely related to the woolly spider monkeys (Brachyteles), and most likely split from such woolly monkeys as ( Lagothrix and Oreonax ) in the South American lowland forest, to evolve their unique locomotory system.This theory is not supported by fossil evidence. Other theories include Brachyteles , Lagothrix and Ateles in an unresolved trichotomy, and two clades, one composed of Ateles and Lagothrix and the other of Alouatta and Brachyteles. More recent molecular evidence suggests the Atelinae split in the middle to late Miocene (13 Ma), separating spider monkeys from the woolly spider monkeys and the woolly monkeys.
The muriquis, also known as woolly spider monkeys, are the monkeys of the genus Brachyteles. They are closely related to both the spider monkeys and the woolly monkeys. The two species are the southern and northern muriquis. They are the two largest species of New World monkeys, and the northern species is one of the most endangered of all the world's monkeys.
Speciation is the evolutionary process by which populations evolve to become distinct species. The biologist Orator F. Cook coined the term in 1906 for cladogenesis, the splitting of lineages, as opposed to anagenesis, phyletic evolution within lineages. Charles Darwin was the first to describe the role of natural selection in speciation in his 1859 book The Origin of Species. He also identified sexual selection as a likely mechanism, but found it problematic.
The Miocene is the first geological epoch of the Neogene Period and extends from about(Ma). The Miocene was named by Charles Lyell; its name comes from the Greek words μείων and καινός and means "less recent" because it has 18% fewer modern sea invertebrates than the Pliocene. The Miocene is preceded by the Oligocene and is followed by the Pliocene.
The genus name Ateles derives from the ancient greek word ἀτέλεια (atéleia), meaning "incomplete, imperfect", in reference to the reduced or non-existent thumbs of spider monkeys.
The genus contains seven species, and seven subspecies.
Spider monkeys are among the largest New World monkeys; black-headed spider monkeys, the largest spider monkey, have an average weight of 11 kilograms (24 lb) for males and 9.66 kg (21.3 lb) for females. Disproportionately long, spindly limbs inspired the spider monkey's common name. Their deftly prehensile tails, which may be up to 89 cm (35 in) long, have very flexible, hairless tips and skin grooves similar to fingerprints. This adaptation to their strictly arboreal lifestyle serves as a fifth hand. When the monkey walks, its arms practically drag on the ground. Unlike many monkeys, they do not use their arms for balance when walking, instead relying on their tails. The hands are long, narrow and hook-like, and have reduced or non-existent thumbs. The fingers are elongated and recurved.
Their hair is coarse, ranging in color from ruddy gold to brown and black, or white in a rare number of specimens.The hands and feet are usually black. Heads are small with hairless faces. The nostrils are very far apart, which is a distinguishing feature of spider monkeys.
Spider monkeys are highly agile, and they are said to be second only to the gibbons in this respect. They have been seen in the wild jumping from tree to tree.
Female spider monkeys have a clitoris that is especially developed; it may be referred to as a pseudo-penis because it has an interior passage, or urethra, that makes it almost identical to the penis, and retains and distributes urine droplets as the female moves around. This urine is emptied at the bases of the clitoris, and collects in skin folds on either side of a groove on the perineal.Researchers and observers of spider monkeys of South America look for a scrotum to determine the animal sex because these female spider monkeys have pendulous and erectile clitorises long enough to be mistaken for a penis; researchers may also determine the animal's sex by identifying scent-marking glands that may be present on the clitoris.
Spider monkeys form loose groups, typically with 15 to 25 individuals,but sometimes up to 30 or 40. During the day, groups break up into subgroups. The size of subgroups and the degree to which they avoid each other during the day depends on food competition and the risk of predation. The average subgroup size is between 2 and 8 but can sometimes be up to 17 animals. Also less common in primates, females rather than males disperse at puberty to join new groups. Males tend to stick together for their whole lives. Hence, males in a group are more likely to be related and have closer bonds than females. The strongest social bonds are formed between females and their young offspring.
Spider monkeys communicate their intentions and observations using postures and stances, such as postures of sexual receptivity and of attack. When a spider monkey sees a human approaching, it barks loudly similar to a dog. When a monkey is approached, it climbs to the end of the branch it is on and shakes it vigorously to scare away the possible threat. It shakes the branches with its feet, hands, or a combination while hanging from its tail. It may also scratch its limbs or body with various parts of its hands and feet. Seated monkeys may sway and make noise. Males and occasionally adult females growl menacingly at the approach of a human. If the pursuer continues to advance, the monkeys often break off live or dead tree limbs weighing up to 4 kilograms (8.8 lb) and drop them towards the intruder. They do not actually throw the branches, but twist to cause the branch to fall closer to the threat.[ clarification needed ] The monkeys also defecate and urinate toward the intruder.
Spider monkeys are diurnal and spend the night sleeping in carefully selected trees. Groups are thought to be directed by a lead female, which is responsible for planning an efficient feeding route each day. Grooming is not as important to social interaction, owing perhaps to a lack of thumbs.
Spider monkeys have been observed avoiding the upper canopy of the trees for locomotion.One researcher speculated this was because the thin branches at the tops of trees do not support the monkeys as well.
At 107 grams (3.8 oz), the spider monkey brain is twice the size of the brain of a howler monkey of equivalent body size; this is thought to be a result of the spider monkeys' complex social system and their frugivorous diets, which consist primarily of ripe fruit from a wide variety (over 150 species) of plants. This requires the monkeys to remember when and where fruit can be found. The slow development may also play a role: the monkeys may live from 20 to 27 years or more, and females give birth once every 17 to 45 months. Gummy, presumably the oldest living spider monkey in captivity, is presumed to have been born wild in 1962 and currently resides at Fort Rickey Childrens Discovery Zoo located in Rome, NY.
The diets of spider monkeys consist of about 70 to 85 percent of fruits and nuts.[ citation needed ] They can live for long periods on only one or two kinds of fruits and nuts. They eat the fruits of many big forest trees, and because they swallow fruits whole, the seeds are eventually excreted and fertilized by the feces. Studies show the diet of spider monkeys changes their reproductive, social, and physical behavioral patterns. Most feeding happens from dawn to 10 am. Afterward, the adults rest while the young play. Through the rest of the day, they may feed infrequently until around 10 pm. If food is scarce, they may eat insects, leaves, bird eggs, bark and honey.
Spider monkeys have a unique way of getting food: a lead female is generally responsible for finding food sources. If she cannot find enough food for the group, it splits into smaller groups that forage separately.[ citation needed ] The traveling groups have four to nine animals. Each group is closely associated with its territory. If the group is big, it spreads out.
The female chooses a male from her group for mating. Both males and females use "anogenital sniffing" to check their mates for readiness for copulation. The gestation period ranges from 226 to 232 days. Each female bears only one offspring on average, every three to four years.
Until six to ten months of age, infants rely completely on their mothers.Males are not involved in raising the offspring.
A mother carries her infant around her belly for the first month after birth. After this, she carries it on her lower back. The infant wraps its tail around its mother's and tightly grabs her midsection.Mothers are very protective of their young and are generally attentive mothers. They have been seen grabbing their young and putting them on their backs for protection and to help them navigate from tree to tree. They help the more independent young to cross by pulling branches closer together. Mothers also groom their young.
Male spider monkeys are one of the few primates who do not have a baculum.
Spider monkeys are found in many aspects of the Mesoamerican cultures. In the Aztec 260-day calendar, Spider Monkey (Nahua Ozomatli) serves as the name for the 11th day. In the corresponding Maya calendar, Howler Monkey (Batz) is substituted for Spider Monkey.In present-day Maya religious feasts, spider monkey impersonators serve as a kind of demonic clowns. In Classical Maya art, they are ubiquitous, often shown carrying cacao pods.
The woolly monkeys are the genus Lagothrix of New World monkeys, usually placed in the family Atelidae.
The Atelidae are one of the five families of New World monkeys now recognised. It was formerly included in the family Cebidae. Atelids are generally larger monkeys; the family includes the howler, spider, woolly, and woolly spider monkeys. They are found throughout the forested regions of Central and South America, from Mexico to northern Argentina.
The brown woolly monkey, common woolly monkey, or Humboldt's woolly monkey is a woolly monkey from Colombia, Ecuador, Peru and Brazil. It lives in groups of two to 70 individuals, usually splitting the group into smaller subgroups when active.
The white-bellied spider monkey, also known as the white-fronted or long-haired spider monkey, is an endangered species of spider monkey, a type of New World monkey. It is found in the north-western Amazon in Colombia, Ecuador, Venezuela, Peru and Brazil, ranging as far south as the lower Ucayali River and as far east as the Branco River. In the past, the Peruvian, brown and white-cheeked spider monkeys have been treated as subspecies of A. belzebuth. As presently defined, the white-bellied spider monkey is monotypic. It has a whitish belly and a pale patch on the forehead, which, despite its common name, often is orange-buff. They live in groups of 20 to 40 individuals, splitting into small parties of 1 to 9 when in activity.
The red-faced spider monkey 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 gray woolly monkey is a woolly monkey species from South America. It is found in Bolivia, Brazil and Peru. Lagothrix cana gets its common name, gray woolly monkey, from its thick gray coat. Its hands, feet, face and the inside of the arms are dark in color. Two subspecies of Lagothrix cana are known: L. c. cana and L. c. tschudii. L. c. cana is found in both Brazil and Peru and L. c. tschudii is found only in southeastern Peru. An isolated population was discovered by Wallace and Painter in the Madidi National Park in Bolivia. This population is distinctively darker and could soon be a new subspecies. The gray woolly monkey has been considered endangered by IUCN since 2008. The species is listed as endangered because the it suffered a 50% decrease in population over the past 45 years due to deforestation and hunting.
Geoffroy's spider monkey, also known as the black-handed spider monkey, is a species of spider monkey, a type of New World monkey, from Central America, parts of Mexico and possibly a small portion of Colombia. There are at least five subspecies. Some primatologists classify the black-headed spider monkey, found in Panama, Colombia, and Ecuador as the same species as Geoffroy's spider monkey.
The white-cheeked spider monkey is a species of spider monkey, a type of New World monkey, endemic to Brazil. It moves around the forest canopy in small family groups of two to four, part of larger groups of a few dozen animals. This monkey feeds on leaves, flowers, fruits, bark, honey and small insects, and it is an important means of seed dispersal for forest trees. Females give birth after a 230-day gestation period. The population of this monkey is decreasing as its forest habitat is lost to soybean production, deforestation and road construction. It is also regarded as a delicacy and hunted for food. For these reasons, the International Union for Conservation of Nature has assessed the animal's conservation status as being "endangered".
The Peruvian spider monkey also known as the black-faced black spider monkey, is a species of spider monkey that lives not only in Peru, but also in Brazil and Bolivia. At two feet long, they are relatively large among species of monkey, and their strong, prehensile tails can be up to three feet long. Unlike many species of monkey, they have only a vestigial 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.
The yellow-tailed woolly monkey is a New World monkey endemic to Peru. It is a rare primate species found only in the Peruvian Andes, in the departments of Amazonas and San Martin, as well as bordering areas of La Libertad, Huánuco, and Loreto. The yellow-tailed woolly monkey was at first classified in the genus Lagothrix along with other woolly monkeys, but due to debatable primary sources, they have been placed in Oreonax. Oreonax has been proposed to be a subgenus of Lagothrix, but others have regarded it as a full genus. A recent extensive study proves that the yellow-tailed woolly monkey may indeed be in Lagothrix.
The black-headed spider monkey is a species of spider monkey, a type of New World monkey, from Central and South America. It is found in Colombia, Ecuador, and Panama. Although primatologists such as Colin Groves (1989) follow Kellogg and Goldman (1944) in treating A. fusciceps as a separate species, other authors, including Froelich (1991), Collins and Dubach (2001) and Nieves (2005) treat it as a subspecies of Geoffroy's spider monkey.
A pseudo-penis is any structure found on an animal that, while superficially appearing to be a penis, is derived from a different developmental path.
The hooded spider monkey, is a subspecies of Geoffroy's spider monkey, a type of New World monkey, from Central America, native to Panama. It also might be found in a small portion of Colombia adjacent to Panama. In western Colombia and northeast Panama it is replaced by the Black-headed spider monkey, A. fusciceps. In western Panama, it is replaced by another subspecies of Geoffroy's Spider Monkey, the Ornate spider monkey, A. g. ornatus. The Hooded spider monkey has long, tawny fur.
The Yucatan spider monkey is a subspecies of Geoffroy's spider monkey, and is one of the largest types of New World monkey. It inhabits Mexico, Guatemala and Belize. It is a social animal, living in groups of 20-42 members.
The Azuero spider monkey is a possible subspecies of spider monkey that is in critical danger of extinction according to the IUCN Red List of Threatened Species. Common names of this subspecies include mono charro, mono charao and mono araña. The Azuero subspecies is one of three types of spider monkeys in Panama; Ateles geoffroyi panamensis with a range spanning from Costa Rica to Darién excluding the Azuero, Ateles geoffroyi fusciceps, with a range spanning Panamá and Colón provinces, and Ateles geoffroyi azuerensis, the Azuero spider monkey, whose range encompasses only the Azuero Peninsula.
Non-reproductive sexual behavior consists of sexual activities animals participate in that do not lead to the reproduction of the species. Although procreation continues to be the primary explanation for sexual behavior in animals, recent observations on animal behavior have given alternative reasons for the engagement in sexual activities by animals. Animals have been observed to engage in sex for social interaction, demonstration of dominance, aggression relief, exchange for significant materials, and sexual stimulation. Observed non-procreative sexual activities include non-copulatory mounting, oral sex, genital stimulation, anal stimulation, interspecies mating, and acts of affection. There have also been observations of animals engaging in homosexual behaviors, as well as sex with dead animals and sex involving juveniles.
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