Originally from the Atlas Mountains and the Rif Mountains of Morocco, the Barbary macaque population in Gibraltar is the only wild monkey population on the European continent. Although most Barbary monkey populations in Africa are experiencing decline due to hunting and deforestation, the Gibraltar population is increasing. As of 2020, some 300 animals in five troops occupy the Upper Rock area of the Gibraltar Nature Reserve, though they make occasional forays into the town. As they are a tailless species, they are also known locally as Barbary apes or rock apes, despite being classified as monkeys. Spanish speakers simply refer to them as monos when conversing in Spanish, although English is the native language as the area is a British overseas territory.

The Barbary macaque, also known as Barbary ape, is a macaque species native to the Atlas Mountains of Algeria, Tunisia and Morocco, along with a small introduced population in Gibraltar. It is the type species of the genus Macaca. The species is of particular interest because males play an atypical role in rearing young. Because of uncertain paternity, males are integral to raising all infants. Generally, Barbary macaques of both sexes and all ages contribute in alloparental care of young.