The weight of a monkey depends on its species. The talapoin monkey, which is one of the smallest monkeys, weighs around 2 to 4 pounds, while a savanna baboon can weigh between 50 to 100 pounds.
Species of the family Cercopithecidae, or Old World monkeys, are generally larger and heavier than New World monkeys, or cebidae. Old World monkeys live in Africa and Asia. The so-called Barbary apes famously live in Gibraltar, but they are not indigenous to the area.
Cebidae monkeys are native to Central and South America and can be tiny. Their small size and light weight make them well adapted to life in the trees.