About Capuchin Monkeys

What is a capuchin?

Capuchin monkeys are the most intelligent and adaptable of all the South American primates. They have the largest brain-to-body ratio of any non-human primates and they are one of only a few animals, apart from man, to construct and use tools.The flexible diet and adaptable lifestyle of the capuchins has enabled them to extract food from sources no other animals can get to and this has made it possible for capuchins to co-exist side by side with other primates with similar diets. They can exploit almost every type of forest in the tropics, from dry deciduous forest, mangrove, lowland rainforest (both primary, disturbed and secondary) to montane forest up to 2700m and all capuchins do occasionally venture down to the ground while foraging. Capuchins have the second largest range throughout Latin America, after the leaf eating howler monkeys, and they are found in every country south of Honduras except in Uruguay and Chile.

Because of the great physical variation capuchins exhibit, and as scientist learn more about speciation (DNA and the evolution of species), the genus Cebus have undergone one of the most dramatic taxonomic changes within the primate world. The debate today is whether there is seven or eight capuchin species, whereas earlier in the 19th Century only 4 to 6 species were recognized. Six of the eight suggested species include numerous additional subspecies.  All species of capuchins have a distinct dark “cap” on the top of their heads; a characteristic that inspired the Europeans who arrived in South America in the 15th Century to name them after capuchin monks. Depending on the shape of the cap the capuchins are often further classified as “tufted” or “nontufted”.

The “tufted” capuchins are the black-capped capuchin (Cebus apella) with six subspecies, the bearded capuchin (Cebus libidinosus) with four subspecies, the black horned capuchin (Cebus nigritus) with three subspecies and the monotypic and critically endangered yellow-breasted capuchin (Cebus xanthosternos). The “untufted” capuchins are the white faced capuchin (Cebus capucinus) with four subspecies, the white-fronted capuchin (Cebus albifrons) with eleven subspecies, the weeper capuchin (Cebus olivaceus) with five subspecies and the monotypic Ka’apor capuchin (Cebus kaapori). Scientists still disagree about whether the latter should have full species recognition or be labeled as a subspecies of C. olivaceus. These classifications are by no means distinct and there is considerably variation within each; in captivity two members of different species or sub-species can breed, although the various types usually live in different habitat niches in the wild.

At the sanctuary we have established a weeper capuchin group and a black-capped capuchin group, both of which possibly contain several different subspecies. To make it even more complicated there are also some hybrids amongst our rescued capuchins, but our goal is to get all new arrivals integrated into either one of the existing groups.

Clever Capuchins

What makes capuchins special amongst primates is their exceptionally active and intelligent minds, their never ceasing alertness and the very dexterous fingers that gives them perfect precision grips. Capuchins are in fact one of only a few animals – and the only monkey – known to both manufacture and use tools in the wild; a trait that was once attributed solely to humans. For example, capuchins employ a variety of nut-cracking techniques, including one where they have to choose rocks of the right shape to use as hammers, carry them for considerable distances to the particular stone they always use as the anvil and then place the nut in the right angle so that they will be able to strike down on it with the hammer and break open the shells. Capuchins in the wild also use rocks and sticks as ammunition to scare off predators and at the Sanctuary the same type of objects are often used  in attempted territory demolition or as special aids in heated arguments. Our capuchins also like to rub their bodies with strong smelling substances like spring onions or chilies – a behaviour that in the wild aids to keep away mosquitoes and other biting insects. As a matter of fact, wild capuchins have developed their own insect repellent; by squirting millipede innards or rub particular leaves over themselves and each other.

Capuchins in the wild

The capuchin genus as a whole is a very successful primate, capable of adapting to new situations as they arise and thus able, to some degree, to cope with human disturbances to their habitat. Because they can live in a variety of forest types and because they are able to move comfortable on the ground if they have to, most capuchin species are not yet threatened by extinction. In fact, some countries still have a legal right to export a set quota of wild caught, live capuchins every year and there are thus still today wild born individuals legally entering the UK primate pet trade. However, because of the limited distribution of some capuchins there are also two critically endangered species amongst them. One is the monotypic C. xanthosternos who lives in a heavily hunted part of the Brazilian Atlantic forest and the other one is a subspecies of C. apella restricted to a single island in Venezuela.

Depending on the quality of the habitat a capuchin group will have a home range of anything between 25 to 300ha. Capuchins constitute a substantial part of the food chain in some areas, being both predators and prey animals, and they have an important role to play in the forest ecosystem. Some rainforest seeds are more likely to germinate, or they will germinate sooner, if they have passed through a frugivorous primate’s digestive system, however, capuchins are usually chewing the seeds and thus destroying, or reducing, their germination potential. Even if they destroy some plants with their extractive foraging techniques they probably do the plants considerable favours as well by pollinating flowers as they feed on nectar, by dispersing smaller seeds when eating fruits, by enhancing fruit production when eating the fresh buds of some tree species and by ridding the plants of parasites as they feed on invertebrates..

Capuchins share their habitat with other animals that will benefit from their quick-witted predator defense and feed on the remains of the food that capuchins have managed to extract. Several other species of primates are often seen traveling together with the capuchins, including the small squirrel monkeys, the uakari, saki and even the large spider monkeys.

Capuchin Social Behaviour

All capuchins live in “matrilinear” multi-male – multi-female groups of between 10 to 30 individuals, depending on species.“Matrilinear” means that the females will stay in the group where they were born all their lives, whereas the males will migrate at the latest upon reaching maturity. The number of males and females in each group will vary from species to species. All capuchins have a dominant alpha male, but the extent of their dominance varies from strict despotism with exclusive mating rights to more cooperative group defense provided by several males.  The males are larger and more muscular than the females and their duties are to physically protect the group from external threats, but capuchin females are very influential within the groups as well, particularly in the formation and backing up of alliances.

Capuchins keep up their relationships with other monkeys through proximity, physical contact, grooming, food transfers and alliance formations. Grooming is said to be the non-human primates’ equivalent to human small talk; it is important for maintaining friendships, making up after a quarrel, for showing dominant individuals respect and of course for keeping each other clean and tidy. Female capuchins are able to use their influence and power when they choose a partner to mate with and it is usually, but not always, the dominant male she prefers to consort. The female thus decides when she is ready to mate and chooses her partner—if the object of her affections is not forthcoming, she may give him a quick slap and pull on his fur!

Sexual behaviour varies between species; female black-capped capuchin for example, mainly solicits the alpha male, who is despotic in his dominance and very protective of his females and youngsters. He will only mate once a day and afterwards the female will mount the male by hugging him from behind. As her receptivity recedes, she will mate with several subordinate males as well. Female white faced and white fronted capuchins, in contrast, often primarily choose to mate with lower ranking males. This might be a female strategy to avoid infanticide by giving upcoming males a reason to believe that they have fathered the female’s offspring.However, paternity studies using DNA shows that the alpha males still fathers most infants in all examined species and infanticide has been documented in many capuchin species, despite the female’s mating strategies. By killing infants fathered by others, the males can promote the success of their own genetic line.

Gestation lasts on average 155 days, or little more than 5 Months. The babies are born relatively helpless and are, for example, unable to regulate their own body temperature or keep their bodies upright. Despite growing rapidly during the first few months of life, infants do not complete weaning until they are on average 20.5 months. Capuchins are special amongst polygamous primates for the extent of alloparenting that they exhibit from very early on when the infant is just a few days to a few weeks old. It is common for the child-care to be, not only, shared amongst the females and the infant’s siblings, but also by the males. The birth intervals in most species is just under two years and with an average life span of about 42 years, a single female can give birth to around 17 infants in her lifetime.

The youngsters growth pace slows down considerably after weaning and physical maturity might not be reached until the capuchin is around 10 years old, so the individual will thus spend a long time in a juvenescence period. Sexual maturity is reached well before physical maturity and happens at different ages for females and males and it also it varies from species to species as well as between captive and wild animals. The timing can vary as widely as between the age of 3 and 8 years. However, in a natural population it is unlikely that a young monkey will have much sexual appeal for the opposite sex and the onset of reproduction might thus not coincide with sexual maturity.

Capuchin Communication

Capuchins live in complex societies with social networks expanding over several neighbouring groups and to make themselves understood and maintain all these relationships they make use of a vast number of different communication signals.  Just like humans capuchins communicate with facial expressions and body language just as much as they do with their vocal language. They gesticulate, flash their eyebrows, grin with half bared teeth, scream, purr and much more to explain their needs, feelings and tell of dangers. Each individual also uses their own unique perfume to let everyone know about their presence in the territory and tell of, to us humans, unknown secrets. By rubbing their urine over hands, feet and fur they will mark the branches as they move around their territory and it is also believed that washing their hands with urine gives them a better grip.

At the Sanctuary the capuchins are generally much louder and more ‘up-front’ than the woollies. If they do not receive the attention that they were hoping for, they will promptly grab a loose object, for example a piece of wood, and start banging it on the hatches to the enclosures to make as much noise as they possibly can.

Implications for Rehabilitation at the Sanctuary

Because all of our capuchins are ex-pets that have lived without any social contacts with other monkeys, many of their behaviours are unnatural, but knowledge about the lives of wild capuchins helps us to understand the primary needs of the capuchins in our care. The monkeys need to be physically, mentally and emotionally healthy and with a limited environment at the Sanctuary, the monkeys’ social life is all-important. Not only do the individuals who arrive here often need to learn to adapt after years of isolation, they also have to contend with differences between species. We discovered quite quickly that different species use different behaviours and vocalisations and thus it can be difficult for them to communicate with each other; in fact, when Frosty (a black capped capuchin) and Peppy (a weeper capuchin) first met, Peppy interpreted Frosty’s excited high-pitched black-cap greeting as the very similar and aggressive high-pitched attack noise that weepers make when angry. This led to a literal “breakdown in communication” and the two have never been able to mix well with each other. Thankfully, both monkeys now have a number of other companions to choose from in their daily social life so this minor dispute has led to no lasting problem.

The Day-To-Day Care of the Monkeys

Although work for staff in the summer and winter periods is very different, the same daily routine with regard to the monkeys must be maintained throughout the year to maintain their health, the cleanliness of the territory and also to provide the monkeys with a regular structure to their lives; frequent changes would prove very stressful.

The Capuchin Diet

Capuchins enjoy a much more varied diet than woolly monkeys both in the wild and at the Sanctuary. The capuchin’s adaptability and dietary flexibility allows them to find food in places where other primates can not survive. Their intelligence and inquisitive nature means that they can find food even where it may seem sparse or inaccessible. By using tools as well as their strong canine teeth, they are able to crack open nuts and shell fish and catch and eat even the best protected insects.

Capuchins require a higher level of protein than woolly monkeys and therefore we regularly supplement their diet with nuts, eggs, meal worms, cockroaches and crickets in addition to the chicken which they share with the woolly monkeys once a week. To avoid their cockroaches running away, the capuchins catch them and flip them onto their backs so that they can enjoy their snack at their leisure.

Unlike the woolly monkeys, capuchins tolerate the high levels of sugar found in our most common imported fruits like bananas and peaches and they are also able to digest citrus fruit. In addition we give them a range of root vegetables as well as pumpkins, cauliflower, broccoli, cabbage and carrots.

The capuchins are fed twice a day with a few snacks in between meals. It is important that the food is distributed throughout the territory to allow all monkeys in social groups an equal opportunity to get to the food. By distributing the food around, scattering it out and hiding it around the enclosures, we are encouraging the monkeys to forage and actively search for food in the same way they would do in the wild and thus providing them with added stimulation. Because of their backgrounds as pet monkeys and because most of them exhibit some form of stereotypic behaviour which they have acquired living in confined spaces with limited social lives and little stimulation, it is particularly important that we encourage natural behaviours like food searching. This will prevent them from falling into the old patterns of pacing, head-twisting, rocking etc that they have learnt to do in attempts to reduce the boredom they have experienced in their previous homes. To help keep our capuchins entertained and occupied we are offering different types of “enrichments” for them to investigate (existing new objects, food items, parcels with hidden things etc) on a daily basis.