They have also been seen fighting capuchins. Females actively choose their mates and initiate copulation, sometimes preferring to spend the entire mating period with one male, at other times mating with several males in one day. Males normally don t fight for mates and there is no clear relation between rank and reproductive success. Females give birth to single infant every 2-4 years. Infants are normally dependent for 3 years and reach sexually maturity at age 4 for females and age 5 for males.
Females migrate to other groups more often than males.
Their lifespan in captivity ranges from 30-40 years. All of this varies somewhat with the species. Spider monkeys are hunted for food and their habitat is disappearing. There is also a lucrative pet trade. Their large group numbers and noisy habits reportedly make spider monkeys very easy to find.