Black Spider Monkey

The black spider monkey has exceptionally long, slender limbs and an even longer tail. Where possible, the spider monkey will run on all fours along the tops of branches. But where there is a break in the intertwined canopy of the trees, it will swing or leap from one tree to another. On the rare occasion when the spider monkey sets foot on the ground, it may walk upright on two legs with its long tail held stiffly up against its back. The spider monkey lives in loose-knit, nomadic troops which vary in size according to the availability of food. There are usually no more than 18 monkeys per square mile of forest, but where food is plentiful, as many as 100 may live together.

Spider monkeys communicate their intentions and observations using postures and stances, such as postures of sexual receptivity and of attack. When a spider monkey sees a human approaching, it barks loudly similar to a dog. When a monkey is approached, it climbs to the end of the branch it is on and shakes it vigorously to scare away the possible threat. It shakes the branches with its feet, hands, or a combination while hanging from its tail. It may also scratch its limbs or body with various parts of its hands and feet. Seated monkeys may sway and make noise. Males and occasionally adult females growl menacingly at the approach of a human. If the pursuer continues to advance, the monkeys often break off live or dead tree limbs weighing up to 4 kg and drop them towards the intruder. They do not actually throw the branches, but twist to cause the branch to fall closer to the threat. The monkeys also defecate and urinate toward the intruder.

The black spider monkey has no defined breeding season and gives birth at all times of year. Still, it is slow to mature and is unable to breed until it is five years old.

Each morning, The spider monkey troop breaks up into two or three smaller groups, which disperse to forage for food. The black spider monkey's large size means that it is not threatened by the eagles and hawks that prey on smaller primates. Consequently, it does not require the safety of a large group to be protected from predators. While feeding, the monkeys keep in contact with each other by their loud calls, which sound similar to the whinnying of a horse. The spider monkey feeds chiefly on fruit and nuts but also eats leaves, seeds, flower buds, birds' eggs, insects, and spiders. Fruit is an essential source of water. The spider monkey often suspends itself from a branch by a leg or its tail. This allows it to reach down to pluck fruit or flowers from the tip of a branch. Its long tail is do well adapted that is can pick up small objects such as nuts.