The gelada (Theropithecus gelada, Amharic: ጭላዳ, romanized: č̣əlada), sometimes called the bleeding-heart monkey or the gelada baboon, is a species of Old World monkey found only in the Ethiopian Highlands, living at elevations of 1,800–4,400 m (5,900–14,400 ft) above sea level. It is the only living member of the genus Theropithecus, a name derived from the Greek root words for "beast-ape". Like its close relatives in genus Papio, the baboons, it is largely terrestrial, spending much of its time foraging in grasslands, with grasses comprising up to 90% of its diet.
It has buff to dark brown hair with a dark face and pale eyelids. Adult males have longer hair on their backs and a conspicuous bright red patch of skin shaped like an hourglass on their chests. Females also have a bare patch of skin but it is less pronounced, except during estrus, when it brightens and exhibits a "necklace" of fluid-filled blisters. Males average 18.5 kg (41 lb) and females average 11 kg (24 lb) in weight. The head-body length is 50–75 cm (20–30 in) with a tail of 30–50 cm (12–20 in).
The gelada has a complex multilevel social structure. Reproductive units and male units are the two basic groupings. A band comprises a mix of multiple reproductive units and male units; a community is made up of one to four bands. Within the reproductive units the females are commonly closely related. Males will move from their natal group to try to control a unit of their own and females within the unit can choose to support or oppose the new male. When more than one male is in the unit, only one can mate with the females. The gelada has a diverse repertoire of vocalizations thought to be near in complexity to that of humans.
The population of geladas is thought to have dropped from 440,000 in the 1970s to 200,000 in 2008. It is listed as Least Concern by the International Union for Conservation of Nature (IUCN).
Since 1979, it has been customary to place the gelada in its own genus (Theropithecus), though some genetic research suggests that this monkey should be grouped with its baboon (genus Papio) kin; other researchers have classified the species even more distantly from Papio. While Theropithecus gelada is the only living species of its genus, separate, larger species are known from the fossil record: T. brumpti, T. darti and T. oswaldi, formerly classified under genus Simopithecus. Theropithecus, while restricted at present to Ethiopia, is also known from fossil specimens found in Africa and the Mediterranean into Asia, including South Africa, Malawi, the Democratic Republic of the Congo, Tanzania, Uganda, Kenya, Ethiopia, Algeria, Morocco, Spain, and India, more exactly at Mirzapur, Cueva Victoria, Pirro Nord, Ternifine, Hadar, Turkana, Makapansgat and Swartkrans.
The two subspecies of gelada are:
Northern gelada, Theropithecus gelada gelada
Eastern gelada, southern gelada or Heuglin's gelada, Theropithecus gelada obscurus
