Monkey is a word that is used to refer to many different species of primates, but in particular it most often means orangutans, chimpanzees, gibbons and gorillas. However, the word can also be used to refer to any other species of primate with a flexible and intelligent brain that is capable of adapting to its environment, such as marmosets, baboons and squirrel monkeys. Author Terry Pratchett made this distinction between apes and monkeys clear in his Discworld books by making the Librarian of the Unseen University an orangutan, who gets very upset when people call him a “monkey”.
Generally, monkeys are omnivores, and they will eat both plant and animal material. Fruits are an important part of their diet, and some species, such as saki monkeys, may eat up to 50 different fruits in a day! Other species, such as colobus monkeys and langurs, eat leaves, shoots, flowers and bark. They eat these foods because they contain essential vitamins and minerals.
Males of certain South American species, such as titi monkeys and marmosets, form pair-bonded breeding pairs that are monogamous. Other species, such as macaques and baboons, live in multimale, multifemale groups.
During the day, monkeys seek out food and shelter in trees, and they sleep at night, usually in high locations where predators cannot reach them. Some species, such as spider monkeys, have long tails that help them hold on to branches while they collect their food. Some monkeys, such as colobus monkeys and geladas, have large cheek pouches that they can fill up with nuts, fruit and leaves. They can store food in these pouches, and then chew it and swallow it later when they have time to eat.