ECUADORIAN WHITE-FRONTED CAPUCHIN

Cebus aequatorialis

Geographic Distribution and Habitat

As the name suggests, the Ecuadorian white-fronted capuchin is primarily found in Ecuador.

This capuchin monkey is arboreal and is distributed in the tropical and subtropical forested regions of western Ecuador and northern Peru. The population density is about 2–22 monkeys for every 0.38 square miles (1 sq km).

Seen in both private and publicly protected areas, these monkeys are typically found between the Guayllabamba River in the north to the Cerros de Amotape National Park in the south.

They’re found at elevations ranging from sea level to about 6,561 feet (2,000 meters) on the slopes of the Western Cordillera of Bolivia, which is part of the Andes mountain range.

The Ecuadorian white-fronted capuchin prefers mature forests close to running water sources like streams or rivers. However, they may also be found in forests that have started to die out.

TAXONOMIC NOTES

The Ecuadorian white-fronted monkey was previously considered a subspecies of the Humboldt’s white-fronted capuchin, cebus albifrons. It was designated as a distinct species, the cebus aequatorialis in 2013.

Size, Weight, and Lifespan

The Ecuadorian white-fronted capuchin is a medium-sized monkey that exhibits bilateral symmetry in its body, which means that its right and left halves are nearly identical to each other, like most mammals.

These monkeys have bodies that are 13.7–19.6 inches (35–50 cm) long, with tails that can grow to 15.5–19.6 inches (39.5–50 cm), making their tails as long as or even longer than their bodies.

The length of the tail is to ensure that they are long and strong enough to balance the weight of their bodies. Ecuadorian white-fronted capuchins have prehensile tails, which means they can be used to grab onto objects or branches while the monkeys forage for their food.

Males tend to be heavier than females, at about 7.4 pounds (3.4 kgs), while females tend to weigh around 6.3 pounds (2.9 kgs).

Little is known about the lifespan of Ecuadorian white-fronted capuchins, but monkeys of the Cebidae family tend to be long-lived. In captivity, they may live up to 45 years or more, while those in the wild may live to about 40 years.

Appearance

The front of the Ecuadorian white-fronted capuchin tends to be a very pale yellowish-white, which becomes very slightly darker near the belly as compared to the chest. The rest of the fur is brown, and the shades of color vary from monkey to monkey. Usually, the fur is almost cinnamon in color, with a darker line of fur down the middle of the back.

They have gray-brown faces and hands, and lighter brown feet. In males, the tip of the tail may be a lighter brown than the rest of the body.

This monkey species is fairly slim and most of its body weight is in its limbs to allow it to travel easily from tree to tree in search of food.

Diet

The favored diet of this monkey comprises fresh fruits and nuts from over thirty different plant species including mangos, figs, and palm fruits.

This diet is why the Ecuadorian white-fronted capuchin is often seen as a pest by owners of corn, banana, plantain, and cacao plantations, since the monkeys tend to feed off the cultivated fruits.

The monkeys may also supplement their diet with nectar, tender leaves of plants that grow on the surface of other plants and trees like bromeliads, insects and invertebrates, and their eggs.

In lean times, the white-fronted capuchin may also forage on smaller birds and their eggs, crabs, and other invertebrates to survive. Hence, the monkey can be viewed as competition by fishermen and is often chased off popular crab-gathering grounds by humans.

Behavior and Lifestyle

As a diurnal, arboreal species, the white-fronted capuchin forages for food on trees in the mornings, and sleeps at night. They typically forage on fruit trees, but they may also descend to the ground when food is scarce to look for prey animals and invertebrates.

As with other capuchins, tool-use has been observed among Ecuadorian white-fronted capuchins, which indicates their intelligence. Tool-use is among the many behaviors that is used to measure intelligence in animals, and was seen as behavior unique to human beings and chimpanzees. However, this idea is changing with more observation.

Capuchin monkeys have been observed checking dried leaves for insects and using leaves as cups to drink water. They have also been seen breaking their food into pieces to make them easier to eat.

Their incredible curiosity and relatively large brain compared to body size make the Ecuadorian white-fronted capuchin among the most intelligent monkeys that we know about.

In areas with large human populations, these monkeys are elusive. They run as soon as they are spotted, so it is difficult to imagine what kind of collaborative relationship people might be able to build with them when they don’t view them as pests, but rather as intelligent creatures who are being hemmed in by a loss of habitat.

Daily Life and Group Dynamics

This capuchin monkey species lives in groups of 5–20 members for safety and to meet their social needs, which are so intense that they cannot live alone. They may even associate with other monkey species, like spider monkeys, if exposed to them while they are young and frequently intermix with other capuchin monkeys in the same habitat.

Apart from foraging, Ecuadorian white-fronted capuchins spend most of their time grooming each other, though the dominant male and females of the group may simply receive grooming without performing it for their group members.

Most groups are made up of adult females, with a dominant male leader. The other males in the groups are younger and don’t show aggressive behavior to each other. Aggression is only observed when males of different groups encounter each other, and typically over resources like food.

The group sizes used to be larger, up to 35 members or more, with a minimum of 15 members. However, the decreasing habitat has led to a reduction in the population size, leading to groups that are smaller and smaller in number.

Communication

The Ecuadorian white-fronted capuchin monkey’s communication methods have not been studied extensively. However, capuchin monkeys tend to communicate with each other through calls and body language. They may use their limbs to point and indicate things, raise their brows to express emotions, bare their teeth in aggression, or scream at each other in frustration.

In addition to being predators of insects and small species of birds and invertebrates, these monkeys are also prey to other animal species. So, they have developed a loud call that announces their location to other group members.

Another sound observed among capuchin monkeys is a series of soft squeaks, which is heard when they’re performing an activity that makes them happy, like eating. They may even purr when grooming each other or being groomed.

The most interesting behavior observed among capuchin monkeys is excited babbling. Like human beings, the capuchins may jump around and break branches when overwhelmed with excitement, such as when they’ve scared off a rival group, and are certain they’re safe.

Reproduction and Family

The reproductive biology of the Ecuadorian white-fronted capuchin suggests that the females reach sexual maturity around 4–7 years, with males following about a year later. However, sexual maturity doesn’t guarantee a successful pregnancy. These monkeys typically reach their full adult body size when they’re 15 years old. So even though sexual maturity is observed in monkeys as young as 4 years old, successful reproduction becomes more likely once they grow into their full adult bodies at 15 years.

Among capuchin monkeys, dominant males tend to mate with multiple females. While the mating behavior is unknown, it is very likely that the females chase the males until they become interested and breed.

After impregnation, the females will give birth to a single baby monkey, which they nurse for several weeks. During this time, the babies will cling to their mothers, only letting go to explore their immediate environment occasionally. Mothers look after the babies for about a year, after which the monkeys are considered juveniles. They are looked after by the group as a whole, but the mother is able to go on and breed in the next mating season.

Both males and females in the group join in on the infant care, and young monkeys under 2 months old are typically looked after and nursed by all the dominant females in the group. This is called allomothering.

Ecological Role

The primary importance of the white-fronted capuchin monkeys to the ecological systems they live in is that they help in seed-dispersal. These monkeys primarily forage fruit, and travel from tree to tree in their habitats to do so. As they travel, they leave seeds behind in their droppings, allowing trees to germinate, replenishing the ecosystem.

Conservation Status and Threats

The International Union for Conservation of Nature lists the Ecuadorian white-fronted capuchin as Critically Endangered (IUCN, 2015) appearing on the IUCN Red List of Threatened Species.

This is a direct consequence of its declining habitat and threats posed by conflict with human beings.

As mentioned earlier, these monkeys are seen as pests to crops such as corn and cocoa, since their diets primarily comprise fresh fruit. They are also seen as problematic by crab-hunters, since the monkeys also depend on invertebrate prey in lean periods. Human-wildlife conflicts can arise as a result, with the monkeys on the losing end of the battle.

Deforestation and a rapid rise in human populations have pushed the white-fronted capuchins into smaller and smaller tracts of forests, leading to a decrease in the population. Reduction in forest cover not only means a smaller habitat for these monkeys, it also means a reduction in food sources, leading to increased competition and aggression among troops.

Conservation Efforts

The Ecuadorian white-fronted capuchin is listed in Appendix 2 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 primary effort taken to protect the Ecuadorian white-fronted capuchin has been habitat protection. Most of the regions that these monkeys are currently observed in are protected areas in Ecuador and Peru, as well as privately owned regions.

Further protection of land and water resources is necessary to protect the species and prevent fragmentation of the population, which is when the populations are separated from each other due to human activities like farming or road-building severing animal habitats.

It is also important that the people of the region be involved in conservation efforts and compensated for the loss of their crops. Compensation and information will go a long way to reduce animosity towards these intelligent animals, leading to more effective conservation.

References:

https://journals.sagepub.com/doi/10.1177/194008291200500207
https://www.globalwildlife.org/wp-content/uploads/2019/10/Primates-in-Peril-2018-2020.pdf
https://sta.uwi.edu/fst/lifesciences/sites/default/files/lifesciences/images/Cebus_albifrons%20-%20White-fronted%20Capuchin.pdf
https://digitalcommons.cwu.edu/cgi/viewcontent.cgi?article=2217&context=etd
https://www.iucnredlist.org/species/4081/191702052

Written by Caroline Abraham, August 2023