Behavior of Rhesus Monkeys

The rhesus monkey is a medium-sized member of the genus Macaca, better known as macaques. They grow to more than 3 feet in length, nose to tail, and up to an average of 26 1/2 pounds in weight. It is an Asian Old-World monkey that has also been introduced to Florida. The monkeys have a large variety of behavioral traits.

  1. Social Behavior

    • Rhesus monkeys live in large, mixed-sex family groups that can number up to 200 members. When groups become especially large, smaller groups of females may splinter off and leave the main group. At a later time, solitary males will likely join the female-only groups. This helps to expand the gene pool as most groups have closely-related females and unrelated breeding males, keeping inbreeding to a minimum. Unlike some monkeys that live in groups, rhesus monkeys are not highly territorial and often have home ranges that overlap with other groups. Conflict is rare, with weaker groups often avoiding larger, stronger ones.

    Feeding Behavior

    • Rhesus monkeys are omnivores, but mainly eat vegetation. The monkeys feed within the family groups either high in the trees or foraging on the ground. Roots, herbs, fruits and sometimes agricultural crops make up much of the diet. Insects, small mammals, reptiles, birds and amphibians are also included when available. Specific diet can vary from season to season and the region in which the group lives. Diet is also adapted for living in close proximity to humans, as with some groups found in cities in India. These groups will steal food from the human population and, in some cases, are fed and revered by people.

    Breeding Behavior

    • Similar to other group-living monkeys, the species does exhibit dominance hierarchies. Unlike others, however, it does not mean only dominant males or females get to breed. Females do tend to favor the larger, more dominant males, but the species is promiscuous, and adults of any social rank can breed together. Males of low dominance levels sometimes win females over with kindness, by grooming them or even carrying infants. The females can only breed once a year and usually have only one offspring.

    Defensive Behavior

    • Monkeys that live in groups, like the rhesus monkey, have one main defense against predators, teamwork. While feeding or sleeping, some members of the group will usually be on watch for danger and will sound the alarm by screeching, prompting the troop to flee en masse. Large snakes, birds of prey and carnivores such as tigers and leopards are all likely among the predators of this species.