Monkeys differ from apes and prosimians, primarily in having tails and smaller brains. Apes, like chimpanzees and gorillas, lack tails and are generally larger and more intelligent.
Monkeys groom each other not just for hygiene but to strengthen social ties and improve comfort by enhancing fur insulation.
Only New World monkeys like howler and spider monkeys possess prehensile tails, vital for arboreal life in tropical Americas.
Barbary macaques, originally from Africa, are Europe's sole wild monkeys, found in Gibraltar after centuries of introduction.
Pygmy marmosets, tiny primates of the Amazon Basin, are only about 5 inches long and live in monogamous pairs with shared parental duties.
Mandrills, from central West Africa, are known for their vibrant colors and size dimorphism, with males weighing up to 119 pounds.
Bright red faces in bald uakaris signal good health, aiding in mate selection and reflecting adaptation to their rainforest habitat.
Capuchins use tools, such as rocks to crack nuts and millipedes to repel insects, demonstrating advanced intelligence and tool-making skills.
Howler monkeys possess one of the loudest calls among land mammals, audible up to three miles away due to enlarged throat bones.
Japanese macaques, or snow monkeys, relax in volcanic hot springs to reduce stress, unique behavior observed at Jigokudani Monkey Park.