The Social Life of Monkeys

Monkeys are highly social animals, living in troops that can be huge—up to a thousand members. These groups provide safety from predators and help to share food sources. In addition, monkeys can pass on knowledge about safe and unsafe plants to younger members of their group. These treeswimmers often spread seeds from fruit as they move through their habitat, which helps to ensure that future forests will be able to grow.

Most monkey species are omnivorous. They eat fruits, nuts, leaves, flowers, bark, roots, insects, rodents and birds—pretty much anything they can get their hands on in their habitat. Their diet is vital for their health; it provides nutrients like vitamins, minerals, and dietary fiber. For example, white-faced monkeys vary their diet seasonally so they can fill the demand for fruit during dry seasons when other foods are less available.

Like other primates, monkeys use vocalizations to communicate with one another and signal that a certain behavior is appropriate or not. A monkey might look away to show that it doesn’t want to interact with another, or it might bark to assert its territory. The ability to communicate with one another is important because monkeys can be very territorial and will fight if they feel threatened.

When monkeys see something they want to eat, they must make a big decision in a split second. They must weigh the risk of climbing a tree to reach it against the pleasure and reward of the tasty treat. Their brains evolved to balance expected cortisol and dopamine levels by assessing the chance of success, the amount of effort required, and the probability of another monkey already eating it.