Barbary macaque, (Macaca sylvanus), tailless ground-dwelling monkey that lives in groups in the upland forests of Algeria, Tunisia, Morocco, and Gibraltar. The Barbary macaque is about 60 cm (24 inches) long and has light yellowish brown fur and a bald pale pink face. Adult males weigh about 16 kg (35 pounds), adult females 11 kg. The species was introduced into Gibraltar, probably by the Romans or the Moors. According to legend, British dominion over the Rock of Gibraltar will end only when this macaque is gone. Because it has no tail, this monkey is sometimes incorrectly called the Barbary ape.