Gelada

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, with large populations in the Semien Mountains. Geladas are actually not baboons (baboons are all taxonomic members of the genus Papio) but the only living members of the genus Theropithecus. Theropithecus is derived from the Greek root words for 'beast-ape'. Like its close relatives the baboons (genus Papio), it is largely terrestrial, spending much of its time foraging in grasslands. 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 papionine (baboon) kin; other researchers have classified the species even farther distant 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: The gelada is large and robust. It is covered with buff to dark brown, coarse hair and has a dark face with pale eyelids. Its arms and feet are nearly black. Its short tail ends in a tuft of hair. Adult males have a long, heavy cape of hair on their backs. The gelada has a hairless face with a short muzzle that looks more similar to a chimpanzee's than a baboon's. It can also be physically distinguished from a baboon by the bright patch of skin on its chest. This patch is hourglass-shaped. On males, it is bright red and surrounded by white hair; on females, it is far less pronounced. However, when in estrus, the female's patch will brighten, and a 'necklace' of fluid-filled blisters forms on the patch. This is thought to be analogous to the swollen buttocks common to most baboons experiencing estrus. In addition, females have knobs of skin around their patches. Geladas also have well developed ischial callosities. There is sexual dimorphism in this species: males average 18.5 kg (40.8 lb) while females are smaller, averaging 11 kg (24.3 lb). The head and body length of this species is 50–75 cm (19.7–29.5 in) for both sexes. Tail length is 30–50 cm (11.8–19.7 in). The gelada has several adaptations for its terrestrial and graminivorous (grass-eating) lifestyle. It has small, sturdy fingers adapted for pulling grass and narrow, small incisors adapted for chewing it. The gelada has a unique gait, known as the shuffle gait, that it uses when feeding. It squats bipedally and moves by sliding its feet without changing its posture. Because of this gait, the gelada's rump is hidden beneath and so unavailable for display; its bright red chest patch is visible, though. Geladas are found only in the high grassland of the deep gorges of the central Ethiopian plateau. They live in elevations 1,800–4,400 m (5,900–14,400 ft) above sea level, using the cliffs for sleeping and montane grasslands for foraging. These grasslands have widely spaced trees and also contain bushes and dense thickets. The highland areas where they live tend to be cooler and less arid than lowlands areas. Thus, the geladas usually do not experience the negative effects that the dry season has on food availability. Nevertheless, in some areas, they do experience frost in the dry season, as well as hailstorms in the wet season. Geladas are the only primates that are primarily graminivores and grazers – grass blades make up to 90% of their diet. They eat both the blades and the seeds of grasses. When both blades and seeds are available, geladas prefer the seeds. They eat flowers, rhizomes and roots when available, using their hands to dig for the latter two. They consume herbs, small plants, fruits, creepers, bushes and thistles. Insects can be eaten, but only rarely and only if they can easily be obtained. During the dry season, grasses are eaten less and herbs are preferred. Geladas consume their food more like ungulates than primates, and they can chew their food as effectively as zebra. Geladas are primarily diurnal. At night, they sleep on the ledges of cliffs. At sunrise, they leave the cliffs and travel to the tops of the plateaux to feed and socialize. When morning ends, social activities tend to wane and the geladas primarily focus on foraging. They will travel during this time, as well. When evening arrives, geladas exhibit more social activities before descending to the cliffs to sleep.