Geladas are found in the Ethiopian Highlands in open, high plateaus along the gorges and escarpments that dissect them from about 5,000 feet in elevation up to over 14,700 feet. The monkeys stick close to cliffs to use them as sleeping sites and climb up to the plateaus for their daily grazing and social activities.
There are large populations of gelada in the Semien Mountains. The monkeys form large bands at night, sleeping close together on rocky cliffs and ledges for warmth and safety.
Geladas are genuine grazers, with over 90 percent of their diet being grass blades. They can handily shift to flowers, digging up rhizomes and roots, and foraging for herbs when the availability of grasses decreases.
They spend their days eating and socializing, like many other primates. Grooming, playing, and exercising their peculiar bipedal “shuffle gait” as they eat are paramount to gelada life.
Geladas live in one-male reproductive units that contain one breeding male and 3 to 5 females and their offspring. The dynamic and complex social system of the gelada is a multi-level hierarchy of social units including reproductive units, all-male groups, and large bands.
Though females are about one-third smaller than the males, they run the show and decide when an aging male should be replaced by a younger rival (though he will fight to defend his status). Females remain in their natal group; males migrate out at maturity and try to take over a breeding unit of their own.
If he succeeds, females can choose to support or oppose him. Instead of using his brawn, the new male will groom the females to charm them into favoring him.
