The rhesus macaque[1] (Macaca mulatta), commonly known as the rhesus monkey, is a species of Old-World monkey.
- There are about 6 to 9 recognized subspecies, divided into two groups, those native to China and those native to India.
- The rhesus monkey is brown or gray in color and has a pink face with no fur. It has an average of 50 vertebrae and a large thorax.
- Its tail averages between 20.7 and 22.9 cm (8.1 and 9.0 in). Adult males average about 53 cm (21 in) and weigh about 7.7 kg (17 lb).
- Females are smaller, averaging 19 inches (47 cm) long and weighing 12 pounds (5.3 kg).
- The arm length to leg length ratio is 89.6 to 94.3%.