The capuchin monkeys () are New World monkeys of the subfamily Cebinae. They are famous for their complex foraging skills, such as tool use to crack open nuts. As neotropical primates, their distribution includes tropical forests in Central America and South America as far south as northern Argentina. The highest number is found in Brazil, where they are known as nail monkey (), a common name derived from the nail-like shape of the male genitalia in Brazilian Portuguese. In Central America, they are called white-faced monkeys () in Spanish, where they usually occupy the wet lowland forests on the Caribbean coast of Costa Rica and Panama and deciduous dry forest on the Pacific coast. Capuchins have the largest brain-to-body ratio of any nonhuman primate, as well as complex brain wiring. Their neural complexity is likely related to their sociality and advanced foraging skills. Capuchins have evolved skills to access food that other monkeys cannot and to mentally map food sources in their territories. They are also frequent victims of illegal wildlife trafficking, which is increasing.
Etymology The word capuchin derives from the Order of Friars Minor Capuchin, who wear brown robes with large hoods. When Portuguese explorers reached the Americas in the 15th century, they found small monkeys whose coloring resembled these friars, especially when in their robes with hoods down, and named them capuchins. When the scientists described a specimen (thought to be a golden-bellied capuchin) they noted that: "his muzzle of a tanned color, ... with the lighter color around his eyes that melts into the white at the front, his cheeks ... give him the looks that involuntarily reminds us of the appearance that historically in our country represents ignorance, laziness, and sensuality." The scientific name of the genus, Cebus comes from the Greek word (), meaning a long-tailed monkey.
Classification
The species-level taxonomy of this subfamily remains highly controversial, and alternative treatments than the one listed below have been suggested.Silva Jr., J. de S. (2001). Especiação nos macacos-prego e caiararas, gênero Cebus Erxleben, 1777 (Primates, Cebidae). PhD thesis, Rio de Janeiro, Universidade Federal do Rio de Janeiro.IUCN (2008). 2008 IUCN Red List of Threatened Species. Accessed 23 November 2008
In 2011, Jessica Lynch Alfaro et al. proposed that the robust capuchins (formerly the C. apella group) be placed in a separate genus, Sapajus, from the gracile capuchins (formerly the C. capucinus group) which retain the genus Cebus. Other primatologists, such as Paul Garber, have begun using this classification.
According to genetic studies led by Lynch Alfaro in 2011, the gracile and robust capuchins diverged approximately 6.2 million years ago. Lynch Alfaro suspects that the divergence was triggered by the creation of the Amazon River, which separated the monkeys in the Amazon north of the Amazon River, who then evolved into the gracile capuchins (Cebus). Those in the Atlantic Forest south of the river evolved into the robust capuchins (Sapajus). Gracile capuchins have longer limbs relative to their body size than robust capuchins, and have rounder skulls, whereas robust capuchins have jaws better adapted for opening hard nuts. Robust capuchins have crests and the males have beards.
Genus Cebus Colombian white-faced capuchin or Colombian white-headed capuchin, Cebus capucinus Panamanian white-faced capuchin or Panamanian white-headed capuchin, Cebus imitator Marañón white-fronted capuchin, Cebus yuracus Shock-headed capuchin, Cebus cuscinus Spix's white-fronted capuchin, Cebus unicolor Humboldt's white-fronted capuchin, Cebus albifrons Guianan weeper capuchin, Cebus olivaceus Chestnut weeper capuchin, Cebus castaneus Ka'apor capuchin, Cebus kaapori Venezuelan brown capuchin, Cebus brunneus Sierra de Perijá white-fronted capuchin, Cebus leucocephalus Río Cesar white-fronted capuchin, Cebus cesare Varied white-fronted capuchin, Cebus versicolor Santa Marta white-fronted capuchin, Cebus malitiosus Ecuadorian white-fronted capuchin, Cebus aequatorialis
Genus Sapajus Black-capped, brown or tufted capuchin, Sapajus apella Guiana brown capuchin, Sapajus apella apella Sapajus apella fatuellus Large-headed capuchin, Sapajus apella macrocephalus Margarita Island capuchin, Sapajus apella margaritae Sapajus apella peruanus Sapajus apella tocantinus Blond capuchin, Sapajus flavius* Black-striped capuchin, Sapajus libidinosus Sapajus libidinosus juruanus Sapajus libidinosus libidinosus Sapajus libidinosus pallidus Sapajus libidinosus paraguayanus Azaras's capuchin, Sapajus cay Black capuchin, Sapajus nigritus Sapajus nigritus cucullatus Sapajus nigritus nigritus Crested capuchin or robust tufted capuchin, Sapajus robustus Golden-bellied capuchin, Sapajus xanthosternos
* Rediscovered species. See also:
The oldest known crown platyrrhine and member of Cebidae, Panamacebus transitus, is estimated to have lived 21 million years ago. It is the earliest known fossil evidence of a mammal travelling between South and North America.
Physical characteristics
Capuchins are black, brown, buff or whitish, but their exact color and pattern depends on the species involved. Capuchin monkeys are usually dark brown with a cream/off-white coloring around their necks. They reach a length of , with tails that are just as long as the body. On average, they weigh from 1.4 to 4 kg (3 to 9 pounds) and live up to 25 years old in their natural habitats, and up to 35 in captivity.
Habitat and distribution
They are particularly abundant in Argentina, Brazil, Costa Rica, Honduras, Paraguay, and Peru. But Brazil is the country with the highest abundance of capuchin monkeys, considered the evolutionary start for the robust capuchin genus (Sapajus). Capuchins prefer environments that give them access to shelter and easy food, such as low-lying forests, mountain forests, and rainforests. They use these areas for shelter at night and food access during the day. The canopy of the trees provides protection from threats above, and the capuchin monkeys' innate ability to climb trees with ease allows them to escape and hide from predators on the jungle floor. This environment is mutually beneficial for the capuchins and for the ecosystem in which they inhabit. This is because they spread their seed leftovers and fecal matter across the forest floor which helps new plants to grow, therefore adding to the already abundant foliage that shelters the capuchin.
Behavior
Like most New World monkeys, capuchins are diurnal and arboreal. Capuchins are polygamous, and the females mate throughout the year, but only go through a gestation period once every 2 years between December and April. Females bear young every two years following a 160- to 180-day gestation. The young cling to their mother's chest until they are larger, then they move to her back. Adult male capuchin rarely take part in caring for the young. Juveniles become fully mature within four years for females and eight years for males. In captivity, individuals have reached an age of 50 years, although natural life expectancy is only 15 to 25 years. Capuchins live in groups of 6–40 members, consisting of related females, their offspring, and several males.
Diet
The capuchin monkey feeds on a vast range of food types, and is more varied than other monkeys in the family Cebidae. They are omnivores, and consume a variety of plant parts such as leaves, flower and fruit, seeds, pith, woody tissue, sugarcane, bulb, and exudates, as well as arthropods, molluscs, a variety of vertebrates, and even primates. Recent findings of old stone tools in Capuchin habitats have suggested that recently the Capuchins have switched from small nuts, such as cashews, to larger and harder nuts. Capuchins have also been observed to be particularly good at catching frogs. They are characterized as innovative and extreme foragers because of their ability to acquire sustenance from a wide collection of unlikely food, which may assure their survival in habitats with extreme food limitation. Capuchins living near water will also eat crabs and shellfish by cracking their shells with stones.
Tool Use
Capuchin monkeys are the only neotropical primates that frequently use tools in the wild. Their foraging behavior repertoire includes the use of rocks as both hammers and anvils to open fruits and nuts. This behavior varies in complexity, from smashing a fruit against a hard surface to the more complex action of positioning a nut on a flat stone and striking it with a heavier rock (as a hammer and an anvil). In natural habitats, mastering these skills is a gradual process that can take years of learning and practice because it is a socially learned skill, this means they learn by observing their coespecifics. They also actively choose hammer stones of specific weights and sizes depending on the type of food they intend to open. In 2019, archaeological excavations in Brazil revealed that some wild capuchin populations have maintained this stone-tool culture for at least 3,000 years, considered today one of the oldest known records of non-human material culture.
Social structure
Capuchin monkeys often live in large groups of 10 to 35 individuals within the forest, although they can easily adapt to places colonized by humans. The Capuchins have discrete hierarchies that are distinguished by age and sex. Usually, a single male will dominate the group, and he will have primary rights to mate with the females of the group. However, the white-headed capuchin groups are led by both an alpha male and an alpha female. Each group will cover a large territory, since members must search for the best areas to feed. These primates are territorial animals, distinctly marking a central area of their territory with urine and defending it against intruders, though outer areas may overlap. The stabilization of group dynamics is served through mutual grooming, and communication occurs between the monkeys through various calls. Their vocal communications have various meanings such as creating contact with one another, warning about a predator, and forming new groups. The social experience of the capuchins directly influences the development of attention in society. They create new social behaviors within multiple groups that signify different types of interactions. These include; tests of friendship, displays against enemies, infant and sexual intimacy. This creates social rituals that are designed to test the strength of social bonds and a reliance on social learning.
Mating
Capuchin females often direct most of their proceptive and mating behavior towards the alpha male. However, when the female reaches the end of her proceptive period, she may sometimes mate with up to six different subordinate males in one day. Strictly targeting the alpha male does not happen every time, as some females have been observed to mate with three to four different males. When an alpha female and a lower-ranking female want to mate with an alpha male, the more dominant female will get rights to the male over the lower-ranking one.
Sleeping Capuchins generally prefer to nest in tall, emergent trees with many horizontal branches. They tend to sleep away from the trunk to avoid arboreal predators. The number of sleeping sites and how consistently they use them varies across groups and species, though capuchins commonly switch sites nightly.
Intelligence