The rhesus macaque (Macaca mulatta), colloquially rhesus monkey, is a species of Old World monkey. There are between six and nine recognised subspecies that are split between two groups, the Chinese-derived and the Indian-derived. Generally brown or grey in colour, it is 47–53 cm (19–21 in) in length with a 20.7–22.9 cm (8.1–9.0 in) tail and...