Bearded Capuchin, Sapajus libidinosus
BEARDED CAPUCHIN
Sapajus libidinosus
Geographic Distribution and Habitat
The bearded capuchin, also known as the black-striped capuchin, is native to northern and central Brazil, where they are found in dry, deciduous forests and savanna landscapes between the Araguaia and Grande Rivers. Unlike some other species of capuchin, this species is not found in the Amazon rainforest.
Until recently, the bearded capuchin was considered a subspecies of the black-capped capuchin (Sapajus apella). Due to further research and insight, they are now considered to be their own species.
Size, Weight, and Lifespan
Adult males and females both have an average head and body length of 14.6 inches (37 cm), and a tail measuring 16.5 inches (42 cm). They differ dramatically in weight, with males weighing on average 7.7 pounds (3.5 kg) while females weigh just 4.6 pounds (2.1 kg).
Bearded capuchins can live up to 25 years in the wild, but, like many other species, tend to live much longer in captivity.
Appearance
At first glance, bearded capuchins look very similar to other robust capuchin species that are in the genus Sapajus. They have a mixed hair coat which ranges from yellow-gold to dark brown, with darker hair on their head, tail, and around their arms and legs. As they reach sexual maturity, they develop two small, dark tufts of hair on their head and have dark “sideburns” running down the sides of their face. Their face can vary in darkness, but they tend to have lighter hair around the mouth and lower face, showcasing why they are known as “bearded capuchins.” Their thick, strong tails are semi-prehensile and are used to anchor themselves to stronger supports, like vines, to reach food, as well as for balance.
Along with their weight, bearded capuchins display sexual dimorphism, or noticeable physical differences between genders, by the length of their canine teeth, with males having 0.6 inch (1.5 cm) long canines, while females sport 0.4 inch (1 cm) long canines.
They have some features that distinguish them from other capuchins: the hair on their throat is orange, and they have more of a yellow coloration to the backside parts of their body compared with other species.
Diet
Bearded capuchins are omnivores, having a diet consisting of a wide range of both plant and animal material.
Fruit makes up about 50% of their diet, with invertebrates also making up a significant proportion. They also have been observed consuming tree gum, nectar, honey, insects and their larvae, amphibians, reptiles, and birds. They supplement their diet with flowers, buds, and young leaves.
One aspect of the bearded capuchin’s diet has led to the species becoming relatively famous among primatologists. Capuchins are among a group of primates known to use tools for various tasks. The bearded capuchin has been observed engaging in nut-cracking behaviors. Bearded capuchins use stone tools to crack open the hard shells of palm nuts so that they can eat the kernel within. To do this they place the nut on a boulder or hard surface known as an “anvil”, then lift up a stone called a “hammer” with both hands. They then smash the hammer on top of the nut in order to break the shell. They often stand bipedally, or on two legs, while nut cracking, and strategically place the nuts on the anvil in such a way that they have the best chance of cracking the shell successfully.
Behavior and Lifestyle
Bearded capuchins are diurnal—most active during daylight hours—and spend the nights sleeping in trees. Compared to other capuchins who live in rainforests, these savanna-dwelling capuchins spend a higher proportion of their time on the ground. During the day, they spend a large portion of their time foraging and traveling, especially during the dry season when there is less fruit available. They generally move quadrupedally, or on all fours. However, they are also known to walk bipedally when carrying heavy rocks in both arms for nut-cracking. In this case, they use their thick tails for balance.
In terms of an activity budget, 49% of their time is spent foraging, 37% dedicated to traveling, 10% to resting, and 4% to “other” activities, likely social ones such as grooming.
Along with their nut-cracking skills, bearded capuchins have been observed using tools for digging in the ground, searching for roots and tubers, as well as for scaring prey out of hiding spots. In the wild, sticks have also been used to dip for honey.
Predators of bearded capuchins in addition to humans include jaguars, snakes, and birds of prey. Along with alarm calls, hiding, and beating a hasty retreat, bearded capuchins bang stones together to make loud noises in order to intimidate potential predators.
Forget love notes. THROW ROCKS!: When ready to mate, females follow males around and throw stones at them to catch their attention.
Another kind of digging with tools: Wild female bearded capuchins have been seen (and filmed) picking their noses with tools, either blades of grass or sticks! After repeatedly poking her nose until she sneezes, she follows up by inspecting her tool and… licking it clean. (EWWWW!!!)
Bearded capuchins live in highly social multi-male multi-female groups ranging between 8-20 individuals. Generally, these groups contain more females than males, sometimes with a ratio of two females for every one male. Females are philopatric, meaning they tend to remain in the group where they were born, while males migrate to a new group upon reaching sexual maturity. Males also form linear dominance hierarchies, with an alpha male who is dominant over all members of the group. The alpha male is central to the social network of the group, and females show a preference for grooming him, although they will also groom each other. Females also establish linear dominance hierarchies, and form coalitions with other females during instances of conflict. Unlike the alpha male, subordinate males are often found on the edge of the group.
With regard to primate associations, there has been one case of bearded capuchins adopting a baby common marmoset (Callithrix jacchus)! The marmoset ended up living with their adopted family for over a year!
Like other capuchin monkey species, bearded capuchins communicate using a wide variety of facial expressions, including scalp-lifting, lip-smacking, and the open-mouth threat face. Facial expressions are used during courtship rituals, but also during other aggressive and bonding encounters, along with gestures, vocalizations, and body postures. Bearded capuchins emit a number of vocalizations, including alarm calls upon spotting predators, contact calls, whistles, and stress-related calls. Grooming is not only used to remove dirt and parasites but also to reinforce social bonds and the hierarchies within the group.
In the world of the bearded capuchin, females are the ones to solicit breeding. When ready to mate, they will follow the dominant male and attempt to catch his attention, sometimes with rocks and sticks. He will initially be either disinterested or aggressive toward the females, and who can blame him, with all of the “wasted” tools being tossed toward him!? This is followed by “touch-and-run” behaviors, where females touch the male, then run away before he can respond aggressively. Eventually, he reciprocates the females’ interest, and they may mate. (I’m surprised such a daunting strategy actually works!) The alpha male is the father of the majority of a group’s infants, but subordinate males may father a few infants of their own. This mating system where a male has multiple female partners is known as “polygyny”.
Females reach sexual maturity at around five years of age and give birth approximately once every two years, usually to a single infant. Infants are initially carried on their mother’s belly and are later carried on her back. Infants are weaned from mother’s milk gradually but forage independently by two years of age. Males are often considered adults at around five years of age but don’t reach an average adult size until they are around ten years of age.
As fruit-eaters, bearded capuchins aid in the regeneration of their forest habitats by dispersing seeds through their feces as they travel around the habitat. They also play a role in pollination. Like bees and butterflies, they collect pollen from flowers when consuming them and drinking their nectar. They then deposit the pollen on each subsequent flower they visit, thereby pollinating the plants. In addition, they may serve as pest controllers, since a portion of their diet is made up of insects and their larvae. Finally, as a prey species, they also play a role in feeding local predators within their range.
The International Union for Conservation of Nature lists the bearded capuchin as Near Threatened (IUCN, 2015), appearing on the IUCN Red List of Threatened Species.
The bearded capuchin lives in the Brazilian biomes known as Cerrado and Caatinga. The Cerrado is a vast ecoregion of tropical savanna, while the Caatinga is an ecoregion characterized by semi-arid tropical vegetation. Habitat loss is ongoing in both of these regions, due to residential and commercial development, the conversion of these lands for agriculture and aquaculture, and livestock farming and ranching. Most populations of bearded capuchins in the Caatinga biome are isolated on hills and mountains, often damaging or feeding on crops of nearby farms, resulting in conflicts with farmers and often leading to persecution by the farmers.
The bearded capuchin is also widely hunted and collected from the wild for the illegal local pet trade and for bushmeat. Most individuals seized by the Wild Animal Screening Centers are unable to return to the wild due to physical and behavioral disorders resulting from their experience in captivity.
Additional threats are non-native hybrids or exotics deliberately released from captivity causing chaos to the local ecosystems.
The bearded capuchin is listed in Appendix II of the Convention on International Trade in Endangered Species (CITES), an international agreement between governments whose goal is to ensure that international trade in specimens of wild animals and plants does not threaten their survival.
The bearded capuchin is found in a number of protected areas, including, but not limited to:
- Brasília National Park
- Planalto Central Environmental Protected Area
- Lençóis Maranhenses National Park
- Pico do Jabre State Park
- Serra da Capivara National Park
- Delta do Parnaíba Extractive Reserve
- Serra das Confusões National Park
- https://www.alltheworldsprimates.org/Members/Home/MasterPrimate.aspx?tid=1212
- https://animalia.bio/black-striped-capuchin
- https://www.bioexplorer.net/animals/mammals/monkeys/bearded-capuchin/
- https://www.dailymail.co.uk/sciencetech/article-3148493/Capuchin-monkeys-use-sticks-pick-NOSE-Primate-captured-using-tool-groom-video.html
- https://en.wikipedia.org/wiki/Black-striped_capuchin
- https://en.wikipedia.org/wiki/Caatinga
- https://en.wikipedia.org/wiki/Cerrado
- https://www.gbif.org/species/7785578
- https://www.iucnredlist.org/species/136346/192593226
- https://karger.com/fpr/article-abstract/92/3/151/828340/The-Vocal-Repertoire-of-the-Bearded-Capuchin
- https://www.researchgate.net/profile/Antonio-Moura-4/publication/6628621_Stone_Banging_by_Wild_Capuchin_Monkeys_An_Unusual_Auditory_Display/links/55e3486e08aede0b5733bd14/Stone-Banging-by-Wild-Capuchin-Monkeys-An-Unusual-Auditory-Display.pdf
Written by Sienna Weinstein, January 2025