Spider monkeys are among the largest new world monkeys black-headed spider monkeys, the largest spider monkey, have an average weight of 10. Spider monkey is a member of the primitive monkeys of the new world. There are seven different species of spider monkeys that live in central and south america and in northern parts of mexico. Number of spider monkeys is constantly decreasing because of the habitat loss, intense deforestation, hunt (indigenous people eat the meat of.). Spider monkeys find food in the treetops and feast on nuts, fruits, leaves, bird eggs, and spiders. They can be noisy animals and often communicate with many calls, screeches, barks, and other sounds. Spider monkey characteristics the male spider monkey has a body length of 38 48 centimetres, a tail length of 63 82 centimetres and weighs around 9 10 kilograms. The female spider monkey has a body length of 42 57 centimetres, a tail length of 75 92 centimetres and weighs 6 8 kilograms. Most frequently of 2 to 3 individuals, but also into minitroop formations with an adult male, a few adult females and their young. At the end of the day these subgroups reconvene into a single unit at. Spider monkeys are among the largest new world monkeys black-headed spider monkeys, the largest spider monkey, have an average weight of 10. first, we selected a focal adult spider monkey, and while one observer marked its location, two observers recorded via gps (global positioning systems) the location of all the adult individuals that were within a radius of 100 m from the focal animal. We repeated this procedure 20 times during different days and with different focal. Inadequate attention or neglect can cause them to get depressed and aggressive. There are so many cases wherein spider monkeys from zoos and sanctuaries have exhibited aggressive behavior and even hurt visitors. A recent case (august 2012) was that of winston, the caged spider monkey biting mary griffins fingers in a small zoo of ballymena.