Geographic Distribution and Habitat
White-fronted capuchins, also known as Humboldt’s white-fronted capuchins, are endemic to the Amazon Basin of Brazil, Colombia, and Venezuela. They inhabit dry, deciduous forest in the north of their range, tropical lowland, sub-montane and montane rain forest, seasonally inundated forest, and savanna forests. Arboreal quadrupeds, they are typically found in the lower to mid-canopy and understory of the forests.
Cebus albifrons is one of four species included in the family of untufted or gracile capuchin monkeys.
Between 1949 and 1955, Hershkovitz recognized 13 subspecies of Cebus albifrons. This number was later reduced to six by Groves (2001, 2005). However, more recently, scientists determined that the original assessment by Hershkovitz is more accurate. Molecular studies also indicate that about 2.5 and 2 million years ago, the untufted capuchin monkey clade split into different groups: the Western Amazonian group, an Amazonian and Guiana group that includes Cebus albifrons albifrons, and a Western/Northern Andes/ Central America group.
Size, Weight, and Lifespan
Humboldt’s white-fronted capuchins are medium-sized monkeys. Their head and body length is about 15 in (37.5 cm). Tail length for males and females adds an additional 17 in (42.5 cm). Males weigh more than females at 4–7 lbs (1.7–3.2 kg), while the more-petite females weigh about 3–5 lbs (1.4–2.2 kg).
They can live up to 40 years in captivity.
White-fronted capuchins have a black-brown body with lighter hair on the ventral side (stomach area) and around their face. Their expressive face is pink with dark brown eyes and large nostrils right above their mouth.
They have strong jaws and teeth. Males’ canines are about 16% larger than those of females. In fact, the enamel on their teeth is the thickest of all non-human primates, which allows these small creatures to crack the very hard shell of palm nuts. Their forelimbs and hindlimbs are fairly equal in size, which is thought to be an adaptation since they travel on the ground more than other New World primate species.
Their tail is semi-prehensile and entirely covered in hair. Unlike spider monkeys, capuchin monkeys cannot hang from their tail because it could not sustain the weight of their body. Instead, they use it for support and often wrap it around a tree branch while foraging to keep their balance.
They are extremely dextrous. Their fingers are short with pseudo-opposable thumbs and they can move all their fingers independently of the others.
The size of their brain is large compared to their body size.
These monkeys mostly feed on fleshy fruit, palm fruit, and nuts picked from trees or on the ground and spend about 75% of their time foraging. When fruit is scarce, they feed on nectar, insects, lesser vertebrates, and palm nuts. They occasionally eat young birds, eggs, and the young shoots of plants. They are reported to eat 73 species of plants from 33 families. They are adaptable to environmental changes and, when circumstances call for it, they can survive almost exclusively on plants in the bromeliad family (such as pineapple) and seeds. Because they are extremely inquisitive—and great at manipulating objects—they are able to pound on hard shells to break them, rid plants of spines or poisonous hairs by rubbing them against branches, and access food items that other primates cannot consume. They have also been seen using leaves to scoop water out of tree holes and inspecting dried and rolled leaves to find insects and other edible items.
Behavior and Lifestyle
White-fronted capuchin monkeys are diurnal (active in daytime) and spend time both in the canopy and on the ground.
Like all capuchin monkeys, they display self-anointing behavior; that is, rubbing mud, plants, or insects over their bodies. Although other primates practice self anointment, only capuchin monkeys have been observed practicing it as a group. One individual rubbing her fur is approached by another who gets pieces of the rubbing material and starts rubbing her fur as well, and so forth. The monkeys do not rub each other, but rub themselves in close proximity to one another. The materials used for rubbing vary.
The white-fronted capuchin monkeys of a small Amazonian town called Misahualli provide much interest for tourists when they rub themselves with laundry soap. Because they live in proximity to humans, these monkeys also anoint with cigarettes, hot peppers, onions, liquid soap, and cologne. Those in the Manu National Park in Peru collect a half-rotten fruit (Alibertia curviflora) and genipap (Genipa americana) that they also eat. A subspecies living in Trinidad (Cebus albifrons trinitatis) frequently anoint with the inside of seed pods.
Urine rubbing is also practiced by all capuchin monkeys, including white-fronted capuchins. Anointing could serve as a repellant, fungicide, or self-medication. Studies have shown that self-anointing is effective to reduce parasites and it seems that anointing behavior is less prevalent during the wet season when the risk of infections from parasites is lower. One of the pods used by the monkeys in Trinidad is also known to have anti-venom properties and is used to treat skin ulcers and insect bites. Genipap used by monkeys in Peru is also used by humans as insect repellant; additionally, it is ingested as a vermifuge and is said to have potent antibiotic properties.
Chest, muzzle, and anogenital rubbing against trees serve a different purpose; by spreading saliva, glandular secretions, or other pungent material, capuchins mark their territory.
Untufted capuchin monkeys (Cebus) anoint more with plants and more often as a group than tufted capuchins (Sapaju), who prefer solitary anointment with ants or arthropods.
Amazonian folklore is full of tales featuring humans turned into monkeys by a deity. One story recounts that two shamans were punished by being turned into capuchin monkeys because they failed to steal the secrets of fire from an all-female tribe. The first one had his hair singed off and became what we know as a brown capuchin monkey; the other was drunk, fell into the women’s toilet and became a white-fronted capuchin monkey.
The diverse Amazonian cultures also include beliefs that attribute positive or negative characteristics to animals. Capuchin monkeys are often thought of as thieves. If a human were to eat a capuchin monkey, it is thought that he too would become a thief.
Troops range from 10 to 35 individuals with approximately one adult male for each adult female. The troop territory average range is 22 sq mi (35 sq km).
Individuals in the group are organized in linear hierarchies, in which some males are dominant over other males. Females also have a dominance heirarchy in which some females are dominant over others. Males are always dominant over females. Although friendly to each other, sub-alpha males always keep track of the alpha male.
Most of a day in the life of a white-fronted capuchin monkey is spent foraging. The rest of the time is dedicated to grooming. The alpha male and alpha female get most of the grooming—and never return the favor.
It is not unusual for them to travel alongside other monkey species groups, like spider monkeys, as it offers them some protection from predators. They have been observed in the presence of both three-striped night monkeys, Venezuelan red howlers, and black-headed uakaris.
Female white-fronted capuchins seem to be responsible for choosing which direction the group will travel. While on the move, some members of the group may travel on the ground, while others move through the trees in the canopy.
Vocalizations are important and convey various messages. Alert calls are used to warn others in the group of a potential danger; these calls vary depending on the nature of the danger.
- A bark-like “waah” sound is used to alert others of danger coming from the air or the ground by all members of the group.
- Alpha females especially, may utter an “eh-eh” sound towards a predator as they draw closer to the alpha.
- The “yah” sound expresses excitement by members of the group around the alpha male.
Occasionally conflicts arise in the presence of males from rival groups. These can be of the same or another monkey species. It is up to the alpha male to defend the territory. All the males follow him and closely monitor his behavior. In such situations, adults scream while infants whistle and all members of the group resort to “teeth display.” The alpha male may break and throw branches around to excite group members who then start babbling and ward off offenders.
Contact calls (like “arrh”) are used by lost individuals in order to locate their group, and also by females to indicate that the group should move in a different direction.
When everything is peaceful, young capuchins purr and chirp as they establish contact or play with one another; they twitter when they approach a dominant animal.
When foraging or eating, “uh uh” vocalizations can be heard from all members of the group.
White-fronted capuchin monkeys are polygamous and reach sexual maturity between 4 and 5 years of age. They can breed all year long. Unlike other primate species, females do not exhibit any physical evidence that they are ready to mate. Chemical changes in her urine during estrus signal that a female is ready for mating. Females experience estrous until they are 19–22 years old.
After a gestation period of 160 days (about 22 weeks), females give birth to one offspring and cannot breed again for one year, unless the baby dies, in which case they can breed again 8 weeks later. Babies hold on tight to their mothers’ necks, shoulders, backs, or sides. They nurse for several months. Mothers often groom their babies and juveniles. As babies grow and start exploring on their own, they are cared for by the entire group, including males and the alpha male. In fact, capuchin monkeys show a lot of tolerance toward turbulent infants and juveniles.
Infants and juveniles learn by observing adults in the group and in doing so acquire all the skills they need to forage, socialize, and defend themselves against predators. When they reach adulthood, males leave their natal group to join another group.
Because they travel while feeding and eat a lot of fruit, they play an important role as seed dispersers.
The white-fronted capuchin is listed as Least Concern (IUCN, 2015), appearing on the International Union for Conservation of Nature’s Red List of Threatened Species. Populations are decreasing. The major threat to this species across its range is hunting combined with forest loss and fragmentation, however the species is not significantly threatened at this time.
Natural predators include birds, cats, and snakes.
This species is listed on CITES Appendix II. It occurs in a number of protected areas across its range.
Neotropical Primates – August 2002 – The True Identify and Characteristics of Simia Albifrons Humboldt, 1812: Description of Neotype – Thomas R. Defler and Jorge I. Hernández-Camacho
- Journal of Human Evolution (1999) 36, 719-741 – Article no. jhev.1999.0304
- The Conditions for tool use in primates: implications for the evolution of material culture – Carel P. Van Schaik, Robert O. Deaner & Michelle Y. Merrill
- American Journal of Primatology 74:299-314 (2012) – Anointing Variation Across Wild Capuchin Populations: A Review of Material Preferences, Bout Frequency and Anointing Sociality in Cebus and Sapajus – Jessica W. Lynch Alfaro, Luke Matthews, Adam H. Boyette, Shane J. Macfarlan, Kimberley A. Phillips, Tiago Falotico, Eduardo Ottoni, Michele Verderane, Michael E. Alfaro.
- American Journal of Primatology 00:1-13 (2012) 0- Cebus Phylogenetic Relationships: A Preliminary Reassessment of the Diversity of the Untufted Capuchin Monkeys – Jean P. Boubli, Anthony B. Rylands, Izeni P. Farias, Michaele E. Alfaro and Jessica Lynch Alfaro.
- NASA Joint Report – N67-25677 – Centrifugation of the white-fronted capuchins monkey, Cebus albifrons (Humboldt) – James C. Knepton, Jr.
- A Preliminary Review of Neotropical Primates in the Subsitence and Symbolism of Indigenous Lowland South American Peoples – Loretta Cormier
- The Cebines – Toward an Explanation of Variable Social Structure – Katherine M. Jack
- Primates – January 1979 – On the ecology and behavior of Cebus albifrons in eastern Colombia: Behavior – Thomas Richard Defler
Written by Sylvie Abrams, June 2019. Conservation status updated July 2020.