Geladas (Theropithecus gelada) are big and robust primates from the Old World monkeys, with dark brown fur. Males have long and thick manes and a bright red hairless hourglass-shaped skin patch on their chest, surrounded by white fur. Females also have these bare patches on their chest, but they only brighten when in oestrus. Together with the reddening of the patches when these ladies are ready to mate, they also flaunt a necklace of pearls around their chest patch. These 'pearls' are actually fluid-filled blisters, and are thought to have evolved because unlike the closely related baboon, geladas spend most of their time sitting on their bums, eating and chatting.
The gelada feeds on the ground by shuffling around in the squatting position, moving bipedally, little by little, without changing their posture. Feeding is made even easier because of their sturdy and small fingers, which are adapted for pulling grass and digging. They also have small incisors to make the chewing of leaves easier.
Geladas are only found in Ethiopia, in the deep gorges of the Ethiopian plateau. They are restricted to high grassland escarpments and mostly inhabit altitudes between 2000 and 3000 meters. They prefer to sleep on ledges on the cliff faces, and around sunrise almost immediately move to the top of the plateau and start their socialising and feeding activities.
Many predators threaten the gelada, including leopards, jackals, dogs, foxes and hyenas. To escape these bandits they flee to the cliff faces, but sometimes brave males will show off by confronting the threats, and in some cases even mob the predator. Unfortunately, as in most cases, humans also pose a threat to these chatty primates and their habitat, because of deforestation and soil erosion, due to the ever increasing population of the human race. Some are also shot as pests, while others have also been held as laboratory animals in the past.
Despite the increasing threats to the species, they are listed as Least Concern on the IUCN Red List, as they are still abundant and have a large range.
Speech evolution from geladas??
A recent study suggests that the lip-smacking sounds made by geladas may be a clue as to how human speech evolved. Read the interesting article and listen to their eerily human chattering.
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