The spider monkey, Genus Ateles, is one of the many primates that have a prehensile tail (designed for grabbing and holding onto tree branches). This special tail acts as an extra limb and is essential to its way of life. The arms and legs of a spider monkey can carry it through the highest reaches of trees.  Among other New World monkeys, the spider monkeys have a larger form than most and don't depend on other animals for nourishment. Some predators of the spider monkey are certain hawks, jaguars, cougars, and great, big snakes.  By consuming fruits and seeds, they spread and scatter seeds to different parts of forests. As a result of doing this, they help regrow and restore rain forests. 
The black spider monkey can be easily differentiated from other spider monkeys because of its shiny, black hair that spreads around its entire body except for its face, palms, and soles of the feet. They will normally have a pinkish or reddish tint to their face, but this feature will only happen as a monkey grows into an adult. Young monkeys have a darker contrast in their faces which will gradually brighten up.  Brown spider monkeys have hair that is light brown, but turns into a darker brown as they grow. But even with their light brown color, their bellyside, under parts of their limbs and tail are whiter and light.  Spider monkeys have been given this name because of their appearance looking so much like a spider's. 
Their long arms and legs are lanky which is a good adaptation for hanging onto trees and branches. These limbs provide the movement that is required for tree climbing. They use a particular motion called brachiation, which is a swinging motion, hand over hand. Their fingers also assist in hooking over the trees and branches. Their thumbs are not opposable, but rather this kind of primate was designed with a long muscular (prehensile tail). Unlike other tails, this one is conditioned to grab and hold onto branches. Their tail allows them not only to move with flexibility, but also to freely use their hands to look for food. On the ground, the spider monkey walks on both hands and feet. 
Black spider monkeys are one of the biggest among the New World monkeys- these are the monkeys currently inhabiting South America. The average weight for a male black spider monkey is 23.8 lbs and their average height is 1.83 ft. The female's average weight is 21.3 lbs and their average height is 1.81 ft. 
A spider monkey reproduces by sexual reproduction. A female brown spider monkey, also called black-handed spider monkey, is viviparous and can only have one baby at a time. When a female monkey is around the ages of four to five years old, she is able to give birth. For a male monkey though, he will be around five years old when he's ready to reproduce. A female goes into heat, which usually lasts for 26 days, during this age.  Intercourse between two monkeys occurs when the female draws near to the male monkey, offering herself to him. If the male accepts her, together, they will isolate themselves from the rest of the group for a few days.  The time between births ranges from 17 to 45 months, and the female will remain pregnant for up to 232 days. 
The mother will go through a phase in which she stops her menstrual cycle. A period of about three years passes when she will begin again.  After the infant is born, it will grip with its hands around the mother's torso. When the baby reaches five months of age, it will then switch to being carried on the mother's backside instead of the front. The first two years, the baby will rely on its mother for nourishment, but will have to find its own food later in life. As a baby grows, it becomes more independent by feeding its curiosity. Though the young monkey will situate itself close to its mother, it won't depend on her for transportation. 
The spider monkey is native to South America where they range from north in from southern Mexico to Brazil. Spider monkeys dwell in rain forests with high altitudes, much rather preferring to live in the trees than on the ground. Compared to the brown monkeys located in South America, these spider monkeys are more agile. 
A spider monkey will travel with a group of about 30 or so other monkeys. Then, that same group breaks off into smaller groups that position themselves in the same surrounding area. More often than not, the only group seen closely together is a mother and her child. Unlike in most groups of mammals, the female is dynamic and will take charge. Studies show that she will lead the group to food sources on courses that are efficient, careful and fluctuate between days. Males are found to be less capable of providing resourceful ways for the group. 
Spider monkeys are regularly active during the day and sleep at night. They settle themselves high in trees that are unguarded by branches and leaves, leaving an open space to see the sky. They do this for two reasons: a food source is set for them in the trees and to keep away from any threat. If an enemy tries to attack, they will try to fend them off by scaring them or, if that doesn't work, they'll run away. The life expectancy of the spider monkey is around 27 years. 
Spider monkeys live in rain forests and as a result, they feed on mostly fruits and seeds. A small part of their food source also includes insects and eggs. A spider monkey's tail and limbs are used to transport them from tree branch to tree branch, trying to find their food. They'll dangle from the branch, its tail tightly locked onto it as they use their arms and legs to grab and eat their food. Their healthy diet also consists of roots, flowers, leaves, even bark and honey. The amount of food taken in is excessive over the amount of time it takes to eat it. The group led by the female forms smaller groups when food dwindles in size and there isn't enough to satisfy the group's hunger. 
Brown Spider Monkey
Geoffroy's spider monkey
Red-faced spider monkey
- Variegated spider monkey (Ateles hybridus) Matthew Richardson.
- Black Spider Monkey (Ateles paniscus) The Primata.
- Spider Monkey Honolulu Zoo.
- Black spider monkey Ateles paniscus Kristina Cawthon Lang. Dionisios Youlatos.