Monkeys have many adaptations that allow them to survive in natural environments. Their intelligence is well-known, and this helps them to quickly adapt to changes in their surroundings; they also have prehensile and pentadactyl limbs and prehensile tails. Good colour and depth perception help them move through trees with dexterity.
There are a huge variety of monkeys across the world, and scientists have not yet discovered all of them. Depending on the taxonomic splitting, the number of known species ranges from 190 to 350. Due to the variation within this species, adaptations also vary considerably. The strongest delineation is found in the distinction between New World and Old World monkeys.
New World monkeys live in the rainforests of Central and South America, while Old World monkeys live in various habitats across Africa and Asia; therefore, they have adapted to different environments. For example, Old World monkeys lack a prehensile tail. Even within these two groups, there are several differences. Many people believe all monkeys are five-fingered with opposable thumbs. However, spider monkeys only have four digits and no thumb. Each species of monkey has its own adapted traits, whether it is large group size, such as with squirrel monkeys; loud calls, such as with Howler monkeys; or large body size and intelligence, such as with apes.