What is a Rhesus Monkey?

Rhesus macaque, better known as the rhesus monkey, is a diurnal primate found naturally mostly in central, south, and southeast Asia. The monkey is brown or gray in color and possesses a red or pink face and bottom. Rhesus monkeys are intelligent creatures, and generally live together in clusters called troops, which may contain up to 200 primates. Containing DNA similar to humans, rhesus monkeys have been used in research and even beat man into space.

Typically, a male rhesus monkey is larger than a female. On average, males weigh about 17 pounds (about 7.7 kilograms), with a body length of 21 inches (about 53 centimeters). Females average about 18.5 inches (about 47 centimeters) in length and tip the scales at about 11.5 pounds (about 5.2 kilograms). Both males and females possess a medium-sized tail that is approximately nine inches (about 23 centimeters) long. A rhesus monkey is capable of living for more than two decades.

The primates reside in several countries including Afghanistan, India, China, Pakistan, Thailand, Nepal, and Vietnam. The monkeys are adaptable and can be found in various habitats, including grasslands, woodlands, and mountainous regions. Some monkeys even reside in human communities. Typically, the creatures are found at elevations from sea level to about 6,561 feet (about 2,000 meters), but some rhesus monkeys have been found at heights of as much as 13,123 feet (about 4,000 meters) in China and India. Displaying resiliency, some monkeys even reside in snowy and cold climate found in the mountains of China.

The diet of the rhesus monkey consists of leaves, seeds, roots, fruits, and bark, as well as some insects. Primates that live near human communities may raid gardens and even rummage through trash cans looking for food. Some monkeys that live in captivity may eat things like fruited cookies or marshmallows.

During mating season, the monkey’s back legs and behind will become bright red. A female rhesus monkey is pregnant for about 130 to 190 days and will give birth to a single offspring. At birth, a monkey weighs about one pound (about 450 grams).

Due to its similarities to human anatomical and physiological traits, the rhesus monkey has been studied in medical and biological research. By studying the primate, researchers have learned about the various human blood groups. One element of an individual’s blood group, called the Rhesus factor, takes its name from the primate. In addition, the monkey has been studied to help develop smallpox and polio vaccines, as well as drugs to treat HIV and AIDS. The rhesus monkey was also one of the first living creatures to be sent into space and come back alive.