The patas monkey Erythrocebus patas is a large, ground-dwelling species of orange and grey monkey native to semi-arid areas in West and East Africa, including Nigeria, the two Congos and Kenya. Living in open savannahs and semi-deserts, it has evolved into a swift runner, attaining speeds of 55 km/h, making it the world's fastest monkey.This species lives in multi-female groups of up to 60 individuals but only containing a single male for much of the year. The reproductive rate is unusually high and its lifespan very short, often as little as four years, with females becoming reproductively active at the age of three on average, but often dying once they have given birth and raised either a single offspring or two at most. In short, the patas's lifestyle very much epitomises the popular idiom "Live fast, die young".