Physical Characteristics
Spider monkey size ranges from 14 to 26 inches and weight averages about 13 lbs. They have long arms in relation to their body size. The tails of spider monkeys are strong and highly flexible. According to the World Wildlife Fund, "Their prehensile tail allows them to find stability when sitting on branches, to reach out for food at the tip of fragile branches by suspending themselves, and also as a fifth member for moving in perilous places."
Behavior
Spider monkeys gather in groups of about 30. Subgroups also form. These subgroups contain two to six animals. Foraging groups are most active early in the day. At night, spider monkeys sleep in trees, preferably those near ample food sources. When groups are threatened, individuals bark roughly and display agitated behavior. Spider monkeys prefer retreat rather than physical conflict.
Diet
The majority of a spider monkey's diet consists of fruit and seeds. They also feed on bird eggs, insects, flowers and honey. According to the Honolulu Zoo, "They eat large quantities of food over a relatively short period of time and they tend to feed by suspension while hanging, climbing or moving. They do not pick fruit and carry it to another location to be eaten."
Reproduction
Female sexual maturity occurs between four and five years old. Males are sexually mature by about five years old. Females carry their young in the womb for 226 to 232 days. A single baby is the most common configuration. Females give birth every two to five years. Young monkeys are completely dependent on their mothers for about 10 weeks. After that, the babies display more independence. At approximately five months old, young spider monkeys ride on the mother's back for convenience and security.