Gelada

The gelada, sometimes called the bleeding-heart monkey, is a species of Old World monkey found only in the Ethiopian Highlands, living at elevations between 1,800 and 4,400 metres, and the only living member of its genus, Theropithecus, a name derived from Greek roots meaning beast-ape. Like its close relatives the baboons, it is largely terrestrial and spends much of its time foraging in grasslands, with grasses making up as much as 90 percent of its diet. Adult males grow longer hair on their backs and display a conspicuous, hourglass-shaped patch of bright red skin on the chest, a feature also present but less pronounced in females, whose patch brightens and develops a necklace of fluid-filled blisters during estrus. Geladas live in a complex, multilevel society built from reproductive units and male units that combine into bands and then communities, and their vocal repertoire is considered among the most complex of any primate besides humans; the population is estimated to have fallen from about 440,000 in the 1970s to roughly 200,000 by 2008, though the species remains listed as least concern.