The part played by these monkeys in the discovery of the different human blood groups in the 1940s is commemorated by the term "rhesus antigen".
Although rhesus macaques spend much of their time on the ground, these monkeys are found in a very wide range of habitats, from tropical landscapes to temperate areas where winter snow is common. Wooded areas are often chosen, but in India rhesus macaques are found in open agricultural landscapes and have adapted to living alongside people. They are seen in groups, led by females, despite the larger size of males.
Distribution: Their natural range is in southern Asia, extending from Afghanistan eastwards via India to Thailand and southern China. An introduced population also exists in Florida.
Weight: 5.5 - 12 kg (12 - 26 lb); males are heavier.
Length: 64 - 96 cm (25 - 38 in).
Maturity: Females 3 - 4 years; males around 6 - 8 years.
Gestation Period: About 165 days.
Breeding: 1; weaning occurs from 4 months.
Diet: Mainly vegetarian, eating fruit, leaves, seeds, nuts, roots and bark; will eat some invertebrates.
Lifespan: Probably 10 - 15 years; can be up to 30 in captivity.
The tail is short, indicative of the relatively terrestrial lifestyle of rhesus macaques.
The fur is predominantly brown. This species often walks on all fours.
Females have a pair of teats on their chest for suckling their offspring
The fur on the faces of these monkeys is short, emphasizing their expressions. The ears are conspicuous.
Rhesus macaque swim well, so they are able to cross stretches of water in search of food.
Mutual grooming reinforces bonds between troop members and gives them opportunities to remove parasites such as ticks.
Body language is important in these macaques: staring at an another individual, revealing the teeth, is a threat gesture.