gUIANAN Weeper Capuchin
Cebus olivaceus
Geographic Distribution and Habitat
The Guianan weeper capuchin, also called the wedge-capped or weeper capuchin, is a New World monkey found in the tropical rain forests of northern South America. Their habitat range spans northern Brazil, Guyana, French Guiana and, Venezuela. They reside almost exclusively in primary and undisturbed rainforest, which offer a tall and dense canopy. A large canopy is needed as these primates are able to traverse far distances using the upper-level canopy to trek through the forest. On average they will travel between 494 and 741 acres (200-300 ha). Weeper capuchins use branches and vines with their hands, feet, and prehensile tails to help grasp. When not using the canopy for travel, they tend to occupy the middle strata of the trees. They will travel down to the forest floor for foraging purposes. These forests offer dense vegetation and plethora of available food sources.
They also occupy drier parts of forest along riverbeds in Guyana, and French Guiana. These forests are still considered primary and undisturbed and offer a canopy in mid level trees residing along rivers, such as the mangrove.
The Guianan weeper capuchin, also called the wedge-capped or weeper capuchin, is a New World monkey found in the tropical rain forests of northern South America. Their habitat range spans northern Brazil, Guyana, French Guiana and, Venezuela. They reside almost exclusively in primary and undisturbed rainforest, which offer a tall and dense canopy. A large canopy is needed as these primates are able to traverse far distances using the upper-level canopy to trek through the forest. On average they will travel between 494 and 741 acres (200-300 ha). Weeper capuchins use branches and vines with their hands, feet, and prehensile tails to help grasp. When not using the canopy for travel, they tend to occupy the middle strata of the trees. They will travel down to the forest floor for foraging purposes. These forests offer dense vegetation and plethora of available food sources.
They also occupy drier parts of forest along riverbeds in Guyana, and French Guiana. These forests are still considered primary and undisturbed and offer a canopy in mid level trees residing along rivers, such as the mangrove.
Weeper capuchin geographic range, IUCN 2020
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Size, Weight, and Lifespan
Adult Guianan weeper capuchins are considered an average-sized monkey and are comparable to other species of capuchin. Adults weigh around 6.6 pounds (3 kg), though size does vary between sex with males being larger than females. Body length of adults is roughly 11-16 in (27.94-40.64 cm). They have a prehensile tail that can often be as long as their bodies. Skeletal studies of the weeper capuchin have been done to research the relationship between movement and skeletal size. This research has suggested that Guianan weeper capuchins have relatively longer arms and hind legs than other related species of capuchin, as they have been observed in quadrupedal locomotion such as running and jumping more often. The average lifespan for a weeper capuchin is about 25-35 years. In captivity they can live up to about 50 years. Gendered dimorphism has been observed in Guianan weeper capuchins. On average, males weigh 30% more than females. This is common in several species of capuchin. Additionally, males display larger canine teeth than females. Appearance
Light brown to dark brown fur covers the backside of the weeper capuchin’s body. A lighter cream color runs along their underside and along the inner side of their arms. Light brown fur surrounds their outer cheeks and chin. Their faces are hairless and a light pink color. Their black “wedge cap” starts between their eyes and extends to the top of the head, looking similar to the wedge cap style hat often worn in older military uniforms. They have dark brown eyes underneath a slightly protruded brow ridge. Their long fingers and long feet are suitable for grasping. |
What Does It Mean?Allomothering:
Females in a troop share responsibility for caring for the young. Individuals other than the biological mother of an offspring perform the functions of a mother (by caring for an infant temporarily). Gender dimorphism: When the two sexes of the same species have differences in body structure, or anything beyond their sexual organs. Gestation period: The time of pregnancy from conception until birth. Matrilineal society: Is based on a line of descent through the female. Offspring are traced back to the mother as opposed to a patrilineal society, from which descent is traced to the male. |
Diet
Guianan weeper capuchin monkeys are omnivorous, meaning they eat both plants and animals. Their diet is an equal mix of plants, fruits, and invertebrates. The majority of their plant-based diet comes from leafy vegetation and ripe fruit (mostly figs). Their prey consists of snails, wasps, grasshoppers, ants, bird eggs, and insects that occupy certain plants. They spend an equal amount of time foraging and hunting for prey. However, infants have been observed spending more time foraging for plants and fruits rather than hunting. This suggests that hunting and searching for prey is a developed behavior that juveniles must learn over time from adults. This also means that the diet of juveniles is different than that of adults, and that diet is a socially learned behavior that will change with maturity. There are also foraging differences between males and females in the group: males spend more time looking for insects on the surface of branches, whereas females look for insects atop palm trees. While the diet between adult females and males is made up of the same food, they have differences in how they exploit their prey.
Food washing is a curious phenomenon that has been seen in some other primates, such as macaques and even other species of capuchin. There is typically no inherit reason that primates need to wash food, so most research suggests that it is a cultural or behavioral activity. Primates will sometimes simply wash off their sandy or dirty fruits in water before consumption. There have been some observations in the wild and in captivity of weeper capuchins washing off their food before consumption. However—since it has not been widely observed among weeper capuchins—researchers have been wary of stating that this was a learned and observed behavior; rather, they believe these are circumstantial situations.
Guianan weeper capuchin monkeys are omnivorous, meaning they eat both plants and animals. Their diet is an equal mix of plants, fruits, and invertebrates. The majority of their plant-based diet comes from leafy vegetation and ripe fruit (mostly figs). Their prey consists of snails, wasps, grasshoppers, ants, bird eggs, and insects that occupy certain plants. They spend an equal amount of time foraging and hunting for prey. However, infants have been observed spending more time foraging for plants and fruits rather than hunting. This suggests that hunting and searching for prey is a developed behavior that juveniles must learn over time from adults. This also means that the diet of juveniles is different than that of adults, and that diet is a socially learned behavior that will change with maturity. There are also foraging differences between males and females in the group: males spend more time looking for insects on the surface of branches, whereas females look for insects atop palm trees. While the diet between adult females and males is made up of the same food, they have differences in how they exploit their prey.
Food washing is a curious phenomenon that has been seen in some other primates, such as macaques and even other species of capuchin. There is typically no inherit reason that primates need to wash food, so most research suggests that it is a cultural or behavioral activity. Primates will sometimes simply wash off their sandy or dirty fruits in water before consumption. There have been some observations in the wild and in captivity of weeper capuchins washing off their food before consumption. However—since it has not been widely observed among weeper capuchins—researchers have been wary of stating that this was a learned and observed behavior; rather, they believe these are circumstantial situations.
Behavior and Lifestyle
Guianan weeper capuchins are highly social and have complex social systems integrated within their groups. They are diurnal, meaning they are active during the day and sleep at night. They are arboreal animals and, when not foraging, will spend most of their time in the mid-canopy of the trees on branches. Social play is common among infants, juveniles, and young adults.
Like many species of primates, grooming plays a large role in bonding, establishing hierarchy, and integrating maturing youth into the adult realm of the group. Grooming creates trust and social bonds, and is an important part of maturing into adulthood. Youths will use grooming to slowly insert themselves into the adult realm of the group, and it is up to the adults to allow their integration. Grooming is not a free for all, and individuals cannot just groom whomever they please. Young females will rarely groom each other, and will focus on grooming adult females instead. Young females must develop relationships with older females to gain access into their social structure. Young females who do not form these bonds through grooming will slowly lose access to group resources. Adult females will solicit grooming to diffuse aggression. However, dominant females of the group will usually be the ones offering grooming to their inferiors. Inferior females will sometimes even lay down when approached by the dominant females, which is seen as consent to be groomed. Females of similar status in the group will be observed grooming each other more. Since there are fewer males in groups, their grooming “rules” are not as structured. It is still important for young males to groom older males, but there is more mutual reciprocity between males when grooming each other.
Researchers have seen Guianan weeper capuchins interacting with other species. They have been observed sometimes rubbing themselves with millipedes. They’ll put it in their mouths, rub it on their faces and body, and then pass it around to others in the group. The purpose of this bizarre behavior isn’t exactly known, but researchers suggest that when millipedes are threatened they will release an unpleasant chemical as a defense mechanism. These chemicals might act as a “monkey bug spray” for the weeper capuchins. This behavior is most commonly observed during peak mosquito season.
Guianan weeper capuchins are highly social and have complex social systems integrated within their groups. They are diurnal, meaning they are active during the day and sleep at night. They are arboreal animals and, when not foraging, will spend most of their time in the mid-canopy of the trees on branches. Social play is common among infants, juveniles, and young adults.
Like many species of primates, grooming plays a large role in bonding, establishing hierarchy, and integrating maturing youth into the adult realm of the group. Grooming creates trust and social bonds, and is an important part of maturing into adulthood. Youths will use grooming to slowly insert themselves into the adult realm of the group, and it is up to the adults to allow their integration. Grooming is not a free for all, and individuals cannot just groom whomever they please. Young females will rarely groom each other, and will focus on grooming adult females instead. Young females must develop relationships with older females to gain access into their social structure. Young females who do not form these bonds through grooming will slowly lose access to group resources. Adult females will solicit grooming to diffuse aggression. However, dominant females of the group will usually be the ones offering grooming to their inferiors. Inferior females will sometimes even lay down when approached by the dominant females, which is seen as consent to be groomed. Females of similar status in the group will be observed grooming each other more. Since there are fewer males in groups, their grooming “rules” are not as structured. It is still important for young males to groom older males, but there is more mutual reciprocity between males when grooming each other.
Researchers have seen Guianan weeper capuchins interacting with other species. They have been observed sometimes rubbing themselves with millipedes. They’ll put it in their mouths, rub it on their faces and body, and then pass it around to others in the group. The purpose of this bizarre behavior isn’t exactly known, but researchers suggest that when millipedes are threatened they will release an unpleasant chemical as a defense mechanism. These chemicals might act as a “monkey bug spray” for the weeper capuchins. This behavior is most commonly observed during peak mosquito season.
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Daily Life and Group Dynamics
Guianan weeper capuchins tend to live in larger groups of 10-20, but can have groups of as few as 5. Research suggests that they perhaps live in larger groups to be stronger in numbers, as it is harder for predators to attack larger groups. They follow a matrilineal hierarchy, as a single female is dominant in the group. Groups contain more females than males, and are comprised of a single dominant female and a single reproductive male. There are about four adult females to every adult male, and groups are about 50% juveniles. The female youth typically stay within their natal group, while males migrate to other groups once they’re mature enough. Once a male leaves, he does not spend much time alone and quickly finds a new group. New males are usually accepted into groups without resistance, although the new male is not guaranteed to become the new breeder. Daily activity is comprised of foraging and traveling for food, though activities depend on whether it’s the wet or dry season. Days usually begin before dawn and will not end until after dusk. They often use the same sleeping tree more than once. Most of the time spent foraging is done above in the canopy, however certain fruits and plants are only found on the forest floor. When not traveling or eating, they groom or communicate through calls and vocalizations. Taking care of newborns is also a task that falls upon the mother and other females of equal status in the group, although males will sometimes presume child care. |
Fun FactsCapuchin monkeys have the largest brains, of all monkeys, in relation to their body weight. Squirrel monkeys have the largest brains in proportion to their body size. |
Communication
Guianan weeper capuchins have a wide array of vocalizations that each have a unique purpose. Vocalizations can be vital to a group’s safety, as they will use a high-pitched scream to sound the alarm in case of a predator. Along with their high-pitched screams, they have low-pitched “whoos” and sorrowful sounding “whoops.” They are called the “weeper” capuchin due to the sad and mournful sound of these vocalizations.
Along with vocal communications, they also have a series of visual communications. For example, certain facial expressions are associated with specific verbal vocalizations. A high-pitched scream is usually accompanied with a teeth-baring open face. A lip-smacking face is used as a greeting, during grooming, and during sexual intercourse. Visual communications show that communication is more than what primates hear, it’s what they can see and feel as well!
Guianan weeper capuchins have a wide array of vocalizations that each have a unique purpose. Vocalizations can be vital to a group’s safety, as they will use a high-pitched scream to sound the alarm in case of a predator. Along with their high-pitched screams, they have low-pitched “whoos” and sorrowful sounding “whoops.” They are called the “weeper” capuchin due to the sad and mournful sound of these vocalizations.
Along with vocal communications, they also have a series of visual communications. For example, certain facial expressions are associated with specific verbal vocalizations. A high-pitched scream is usually accompanied with a teeth-baring open face. A lip-smacking face is used as a greeting, during grooming, and during sexual intercourse. Visual communications show that communication is more than what primates hear, it’s what they can see and feel as well!
Reproduction and Family
Weeper capuchins live in female-dominant family groups. They are polygamous, meaning they have more than one mate. In these groups there is a single dominant male who is responsible for breeding the most offspring in the group, although multiple adult males have been seen copulating within groups.
Gestation periods last about 150 days and females give birth to a single offspring. Females are reproductively mature earlier (4-6 years) than their male counterparts (7-12 years). The birthing season lasts from May to April. Research has shown that females in larger groups have higher reproductive success than females in small groups.
Females within the group practice allomothering, which is when individuals other than the biological mother of an offspring perform the functions of a mother. Infants are exclusively cared for and carried by their mothers for the first 3 months, but will receive care from several other group females after this period. Allomaternal nursing—or when females nurse offspring that are not theirs—is also very common in Guianan weeper capuchins. This is significant because this is seen in very few primate species. Researchers believe that this community of allomothering is reciprocal, meaning mothers will return the favor for one another.
Weeper capuchins live in female-dominant family groups. They are polygamous, meaning they have more than one mate. In these groups there is a single dominant male who is responsible for breeding the most offspring in the group, although multiple adult males have been seen copulating within groups.
Gestation periods last about 150 days and females give birth to a single offspring. Females are reproductively mature earlier (4-6 years) than their male counterparts (7-12 years). The birthing season lasts from May to April. Research has shown that females in larger groups have higher reproductive success than females in small groups.
Females within the group practice allomothering, which is when individuals other than the biological mother of an offspring perform the functions of a mother. Infants are exclusively cared for and carried by their mothers for the first 3 months, but will receive care from several other group females after this period. Allomaternal nursing—or when females nurse offspring that are not theirs—is also very common in Guianan weeper capuchins. This is significant because this is seen in very few primate species. Researchers believe that this community of allomothering is reciprocal, meaning mothers will return the favor for one another.
Photo credit: Heribert Dezeo/Creative Commons
Ecological Role
Given their wide foraging range and consumption of fruits, Guianan weeper capuchins help disperse seeds throughout the forest. They are relatively agile and intelligent in avoiding danger, but are a part of the larger food web and are susceptible as prey. They will sometimes be food for predators, such as jaguars, boa constrictors, eagles, and ocelots.
Given their wide foraging range and consumption of fruits, Guianan weeper capuchins help disperse seeds throughout the forest. They are relatively agile and intelligent in avoiding danger, but are a part of the larger food web and are susceptible as prey. They will sometimes be food for predators, such as jaguars, boa constrictors, eagles, and ocelots.
Conservation Status and Threats
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Listed as Least Concern by the International Union for Conservation of Nature (IUCN, 2016), the species has a wide-spread population and is quite common. Given that they live in forests that have seen little deforestation or disturbance, they currently face no serious threat to habitat loss or depopulation. While their geographic range is secure now, it is important to preserve their habitats and maintain primary forests for primates and all species that inhabit it.
Aside from natural predators, the Guianan weeper capuchin faces threats from humans capturing and selling them into the pet trade. This species does not fare well as pets. They are highly social and active animals, and suffer in solitary conditions when kept as pets. However, this specific species is not as widespread throughout the pet trade as other species of capuchin monkey. |
Conservation Efforts
Most protection for this primate comes indirectly through governmental protection of their habitat. Countries that Guianan weeper capuchins inhabit, such as Venezuela, Guyana, and Suriname, have been models of forest conservation. Strong forest protection programs and strict laws on deforestation have kept their primary forests intact, ensuring protection for the Guianan weeper capuchin. Countries that value their forest ecosystems show that they value the species that inhabit them, and have been models of how to resist the temptation of selling their land for its resources.
Non-profits like the Wild Capuchin Foundation exist to support ongoing research of all capuchin species. They also aid in forming sanctuaries for threatened or vulnerable species of capuchin. These sorts of groups also advocate against the illegal pet trade and educate the public on the importance of keeping capuchins in their wild habitat.
Most protection for this primate comes indirectly through governmental protection of their habitat. Countries that Guianan weeper capuchins inhabit, such as Venezuela, Guyana, and Suriname, have been models of forest conservation. Strong forest protection programs and strict laws on deforestation have kept their primary forests intact, ensuring protection for the Guianan weeper capuchin. Countries that value their forest ecosystems show that they value the species that inhabit them, and have been models of how to resist the temptation of selling their land for its resources.
Non-profits like the Wild Capuchin Foundation exist to support ongoing research of all capuchin species. They also aid in forming sanctuaries for threatened or vulnerable species of capuchin. These sorts of groups also advocate against the illegal pet trade and educate the public on the importance of keeping capuchins in their wild habitat.
References:
- Masterson, T. J. and Hartwig, W. C. (1998), Degrees of sexual dimorphism in Cebus and other new world monkeys. Am. J. Phys. Anthropol., 107: 243-256.
- O'Brien, Timothy G. (1993). "Asymmetries in grooming interactions between juveniles and adult female wedge-capped capuchin monkeys". Animal Behaviour. 46: 929–938.
- Visalberghi, Elisabetta; Fragaszy, Dorothy M. (1990). "Food-washing Behaviour in Tufted Capuchin Monkeys, Cebus Apella, and Crabeating Macaques, Macaca Fascicularis". Animal Behaviour. 40 (5): 829–36
- Rylands, A.B., Boubli, J.-P. & Mittermeier, R.A. 2008. Cebus olivaceus_old ssp. olivaceus. The IUCN Red List of Threatened Species 2008: e.T43937A10842002.
- Rylands, A.B., Boubli, J.-P. & Mittermeier, R.A. 2008. Cebus olivaceus_old ssp. olivaceus. The IUCN Red List of Threatened Species 2008: e.T43937A10842002.
- http://knowledgebase.lookseek.com/Weeper-Capuchin-Monkey-Cebus-olivaceus.html
- http://www.theprimata.com/cebus_olivaceus.html
- http://capuchinfoundation.org/index.html
- https://video.nationalgeographic.com/video/boubli-capuchin-wc
Written by John DeVreese, March 2018
