Lilac Male White-fronted Capuchin Monkey

The capuchin monkey’s ability to observe their environment and take action to satisfy their goal of getting a protein-packed meal is one indication of how intelligent these primates are. Scientists use a measure called EQ (Encephalization Quotient) to indicate how big an animal’s brain is compared to their body. A larger EQ means that an animal has a larger brain which it uses to navigate the world, find food, and survive. Humans have an EQ between 7.4–7.8 and capuchin monkeys have an EQ of about 4.5, which is larger than a chimpanzee’s EQ!  The larger brains in capuchin monkeys can explain their complex social and ecological behaviors and their ability to adapt to different environments.

These capuchin monkeys have flexible behaviors and modify their feeding strategies depending on where their food is present at that moment. In the dry season, when fruits are rare, Humboldt’s white-fronted capuchin monkeys look for palm leaves that curl into tubes as the leaves dry out. These leaf tubes are the perfect housing for insects that seek shelter from the heat. The monkeys will spend about half an hour at a palm tree, painstakingly looking for these leaf tubes and stripping them of any insects or spiders that are hiding there. They look for maggots in rotting carcasses and break open rock-like termite nests to get grubs. This shows that even if food sources are hidden in a smelly carcass or an underground nest, these monkeys find a way to eat these foods—even if it takes a lot of energy.

If a favorite food is around or the food is packed into a small space, troop members are comfortable feeding right next to each other and have a high tolerance for members entering their personal space. As a troop, this tight-knit group helps to protect all members from predators or rival troops. However, if the food is spread out in the forest, a troop of capuchin monkeys moves in wide bands. Sometimes monkeys might be 8 feet (250 m) apart. With this strategy, the risk of being caught by a predator is higher because the monkeys cannot effectively scan a large area for threats.

These capuchin monkeys are not afraid to leave the safety of the trees and will cross grasslands and bare rocks to reach a good food patch. And while they are on the ground they will opportunistically feed on flowers or fallen fruits. Humboldt’s white-fronted capuchin monkeys are successfully able to adapt to different environments, which makes them better skilled at surviving changes in their habitat due to deforestation and climate change.

Grooming behaviors are seen mostly between mothers and infants. Grooming not only gets rid of dirt and pests stuck in their fur, but it also strengthens social bonds just as humans feel good when they cuddle or hug a loved one. Grooming sessions among adult Humboldt’s white-fronted capuchin monkeys are short (less than a minute) and not a big part of their social aspect compared to other primate species.