Black Spider Monkey lives in the leafages of the Amazon Jungle and is known for being one of the most agile monkeys. Their brain size, in relation to their body mass, is much larger than those of any other member of the Cebidae family (which is one of the five New World monkey families).
The Black Spider Monkey has notably long, sleek extremities and an even longer tail, which is used to wreathe around branches. These monkeys can move through trees using their hands faster than a man can run on the land. Although they prefer walking on all four, they can often be seen hanging in two arms, as well as swinging and jumping from one tree to another. Black Spider Monkeys can rarely be seen on the ground, where they generally don’t feel comfortable. These monkeys reach up to 60 cm in length and 9,5kg in weight, females being smaller than males.
They're also sometimes called "Red Faced Monkeys" because of the facial colour of some individuals
They live in large groups, the size of which is determined by the area. On average, one square kilometre is inhabited by 12 Black Spider Monkeys, but up to a hundred individuals can live in territory of this size if food is abundant. The group is hierarchic, the alpha male leads the group, protects it and all other members of the group respect him, thus fights are very rare. Black Spider Monkeys are active during the day, and they sleep together at night, squeezed together and wreathed the tails around their necks.
Every morning, the group splits into two or three smaller partitions that feed together. Black Spider Monkeys are relatively large, thus they don’t have to be afraid of many predators that hunt smaller monkeys. They feed mostly on fruit and nuts, while leaves, bugs, spiders and bird eggs are also sometimes eaten. Their tail is very important during feeding – it’s used to touch places that are out of sight, and also to reach fruit and other things that are out of reach of their hands.
Black Spider Monkeys don’t have a definite mating period, and the females can get pregnant at any time of the year. Copulation occurs between all members of the group and they don’t stick to regular partners. Gestation lasts for 30 weeks and the young monkeys are quite undeveloped, they spend four months attached to their mother’s belly. They become mature very slowly, starting to feed on their own only two years after birth and sexual maturity is reached at 5 years age for males and 4 years for females. When nursing, the females don’t mate, thus their reproduction is very slow, with each female giving birth on average every three years.
Black Spider Monkey babies are born helpless and they develop fairly slow
Unfortunately, these monkeys are often hunted for meat, as they’re loud and easy to notice by hunters. That combined with the slow reproduction rate, as well as the destruction of their natural habitat has resulted in a slow, but steady decrease in their population and Black Spider Monkeys are facing extinction.