Old World monkey

A male rhesus macaque

Young collared mangabey

Black-footed gray langur

Nilgiri langur

Old World monkeys are a group of primates that belong to the family Cercopithecidae. This family is part of the order Primates, which also includes humans, apes, and other monkeys. The Old World monkeys are distinguished from the New World monkeys by several physical and behavioral characteristics. They are native to Africa and Asia, indicating their geographical distinction from the New World monkeys of South and Central America.

Characteristics

Old World monkeys are diverse in size and habitat, but they share some common traits. They typically have strong, opposable thumbs that allow them to grasp objects and food. Unlike New World monkeys, they have narrow, downward-facing nostrils. Their tails are not prehensile, which means they cannot use them to grasp or hold onto branches as some New World monkeys do. Old World monkeys are also known for their sitting pads (ischial callosities), which are tough, calloused areas on their buttocks that allow them to sit comfortably on hard surfaces.

Classification

The family Cercopithecidae is divided into two subfamilies: the Colobinae, which includes the leaf-eating monkeys such as the langurs and colobus monkeys, and the Cercopithecinae, which includes the cheek-pouch monkeys such as the macaques and baboons. This classification is based on their diet and digestive systems, with the Colobinae having complex stomachs to digest cellulose and the Cercopithecinae having cheek pouches to store food while foraging.

Habitat and Distribution

Old World monkeys are found in a variety of habitats, including savannas, forests, and mountainous regions across Africa and Asia. They are adaptable animals that can live in close proximity to human settlements, although this often leads to conflicts over food and habitat.

Behavior and Diet

The social structure and behavior of Old World monkeys vary widely among species. Many species live in social groups that have a complex hierarchy. Their diet is also diverse, ranging from fruits and leaves to small animals and insects. Some species, like the baboons, are known for their aggressive behavior, while others, like the langurs, are more peaceful.

Conservation Status

The conservation status of Old World monkeys varies from species to species. Some, like the drill and the golden langur, are classified as endangered due to habitat destruction, hunting, and other human activities. Conservation efforts are in place to protect these primates and their habitats, but challenges remain due to ongoing environmental and economic pressures.

See Also

• Primate
• New World monkeys
• Ape
• Human evolution