Spider monkeys are among the largest of the New World monkeys -- measuring up to two feet tall, and with males weighing up to 24 pounds and females about 21 pounds. Subspecies can vary in coloration depending on their habitat, but normally have fur that is some combination of black, brown, white, gold, tan, orange or red in color. When first discovered, these primates were thought to resemble a spider hanging down from its web, an observation which earned the monkey its name. This is because they often dangle their bodies from tree branches, holding on only with their tail and with their long limbs hanging below them. Unlike many primate species, spider monkeys have only four fingers and are lacking opposable thumbs. Their prehensile tail doubles their body length and essentially acts as a fifth limb, helping them grasp branches and balance as they move about the tree canopy.
Habitat & Diet
There are seven known subspecies of spider monkeys and they inhabit primarily Central and South America. Spider monkeys live high in the canopy of the Amazon, rarely leaving the safety of the higher levels for the more predator-ridden forest floor below. The most common predators of spider monkeys are jaguars, eagles and hawks, as well as other primate species and snakes (both venomous and constrictor species).
The spider monkey is an omnivore, but is primarily a frugivore or fruit-eating animal most of the time, with fruit comprising about 83% to 90% of their entire diet. However, depending on fruit availability and time of year, they will eat flowers, leaves, honey, nuts, insects, bird eggs, sap and even bark. Each small group has a specified time and route for foraging that is determined by the dominant female. Spider monkeys, like many other animal species, play an important role in seed dispersal for plants, flowers and fruits throughout their habitat. This helps increase new plant growth in the rainforest, as well as increase biodiversity of plant life.
Spider monkeys are highly social, matriarchal societies that gather in groups of 24-36 individuals, but they are rarely seen all together. If food is plentiful or predation is a present threat, these groups can be twice their normal size. Ultimately, the group size is determined by the alpha female. During the day, spider monkeys will often forage alone or with a few individuals, but at night, they typically sleep in smaller groups of two to eight individuals. They are highly vocal and have numerous types of calls that are used to bond, protect their young, and warn the group of a predator.
There is no set breeding season for spider monkeys. Females determine when or if they will reproduce, only giving birth to a single offspring every two to five years – something determined largely by the food and water availability. If conditions are optimal, the females will go into estrus, and if it is less than ideal, then they will not breed until conditions improve. Newborn monkeys rely heavily on their mother for about three months, and then begin to explore on their own and become largely independent within the group by one year of age. Typically, they leave to join a new group or start their own at around three years of age. Both females and males will move away from their original troop to form new groups or join other groups as they mature.
Meet our Residents
- According to fossil remains, the earliest living ancestors of the spider monkey date back as far as 11,700 years to 2.5 million years ago during the Pleistocene period.
- When faced with an intruder, spider monkeys have been known to break off tree branches and twist them so that they will drop towards the potential threat on the ground.
- Their long, prehensile tails end in leathery tips with distinct grooves -- very similar to human fingerprints.
Status In The Wild
Major loss of habitat, deforestation, and over- hunting has drastically diminished wild populations of spider monkeys across Central and South America. Some subspecies have declined by over 50% in the last 45 years alone. Spider monkeys are very sensitive to changes within their environment, and all species are listed internationally as either Threatened or Critically Endangered.