Macaques are a genus of Old World monkeys found ranging from Northern Africa to Japan. Old World monkeys usually have tails, although unlike New World monkeys, their tails are not prehensile. Some individual species lack tails, earning them the common name of ape, although this nomenclature is technically incorrect. They are the most widespread non-human primate genus, and several species, such as Rhesus and Barbary macaques, are well known to humans.
These monkeys are frequently used in animal experimentation, especially Rhesus macaques, which are easy to keep in captivity. Numerous famous discoveries and experiments have involved this species, ranging from the Rhesus factor in blood to infamous experiments on maternal deprivation carried out in the 1950s. Rhesus monkeys generally live approximately 25 years, and in nature, they prefer a wide range of environments, including grasslands, woodlands, and urban areas. They tend to be bold and intelligent.
Barbary macaques, also called Barbary apes because they lack tails, live in Morocco and Algeria. A small colony of Barbary macaques, likely introduced, inhabits Gibraltar. These monkeys are listed as under threat, due to increased logging activity and killing by farmers and villagers. A popular myth holds that as long as Barbary macaques live on Gibraltar, the British will retain rule there.
All macaques tend to lead social lives in troops ranging from 20 to 200, with a mixture of males and females. Females tend to outnumber males, with most troops following a matriarchal leadership structure. Many are very loud, and fights between males are not infrequent, while most females work cooperatively with one another. They also exhibit sexually dimorphic tendencies, with males visually distinguishable from females in most species.
Pet and captive macaques tend to carry diseases thanks to their confinement, especially a rare form of herpes that is not harmful to them but can be very damaging to humans if it crosses species. As a result, individuals who handle these monkeys should use protection, including gloves and masks, and should make sure that they are fully vaccinated. Any monkeys kept in captivity should also be properly cared for to minimize the risk of spreading such diseases.