monkeys

Monkeys are primates that are not apes. In modern taxonomy, they are divided into two main groups: New World monkeys (Platyrrhini), found in Central and South America, and Old World monkeys (Cercopithecoidea), native to Africa and Asia. These two lineages differ in several anatomical features, including skull and nose shape and dental formulas. New World monkeys typically have broad, outward-facing nostrils and a dental formula of 2-1-3-3, while Old World monkeys have downward-facing nostrils and a 2-1-2-3 formula. Many, especially in the New World, possess prehensile tails that can act as an extra limb; most Old World monkeys lack true prehensile tails. Humans are primates but belong to the ape lineage, not the monkeys.

Monkeys vary greatly in size from small tamarin-like species to large macaques and proboscis monkeys. They are generally diurnal and highly social, forming troops with complex relationships and communication systems. Most species are omnivorous, eating fruit, leaves, seeds, insects, and occasionally small vertebrates. Locomotion ranges from skilled arboreal climbers and leapers to terrestrial runners; brachiation is common in some New World species, while many Old World monkeys walk on all fours on the ground.

Habitat diversity spans tropical forests, savannas, and mountainous regions. Monkeys face threats from habitat loss, hunting, and the illegal pet trade. Conservation status varies by species, with some listed as least concern and others critically endangered; protection and habitat restoration efforts, along with legal safeguards, are in place in many regions.