The Gelada Monkey

They are quite baboon-like, with golden manes and striking elongated faces - leading to them inaccurately being called ‘gelada baboons’ - but are in fact monkeys, and the only species of grass-grazing primates left, the rest having been wiped out when the climate warmed around a million years ago. Apart from humans, they are the world’s most terrestrial primates. 

Gelada monkeys have a fascinating and complex social structures. They reside in packs of up to 1,200 monkeys, a truly astonishing sight when they are on the move. Within the packs, there are dominant males who have ‘harems’, with around 12 females that they mate with. Lurking on the outskirts are rather amusingly glum-looking groups of bachelor males. 

Gelada Monkey in the Simien Mountains

Occasionally, a fight will take place between one - or several at once - of the bachelor males and a dominant male over ownership of the harem. This is often started by the dominant males, who signals the challenge through an elaborate protocol of macho showmanship, that includes emitting high-pitched noises and shaking the branches of a tree while shrieking. 

These fights can last for days and are often brutal - the males have long, sharp teeth - and sometimes end with one of the monkeys being mortally wounded. Sometimes, however, one side will retreat when the game is up; if it is the dominant male who loses, they may stay with the harem but in a kind of grandfather role, looking after the young but not mating with the females. His red patch will also lighten to become pink; the intensity of the colour is dictated by the strength of the monkeys’ hormone levels. 

Gelada Monkey

Another interesting element of their behaviour is the fact that they sleep on cliff edges at night. Fearing being picked off in their sleep by a predator such as a leopard if they sleep on flat ground, they spend the night on ledges which they are able to climb easily thanks to their short, stubby fingers, but where such predators would struggle.

Gelada Monkey in the Simien Mountains

The monkeys are highly sociable. They spend much of their days (often through noisy barks and cries) forming connections with other monkeys and grooming one another, in what is often akin to a giant soap opera, unlike other, more sedate primate species. There is a strict hierarchy within their societies, however; as mentioned between the dominant male and others, but also between dominant and submissive females. One of their behaviours is particularly human: they enjoy spending several hours in the morning sunbathing. 

Woman looking at Gelada Monkey in the Simien Mountains

Gelada monkeys are not an endangered species: however, their numbers have dwindled in recent decades. Tourism can play an important role in ensuring that their numbers remain stable; by providing a strong source of income to often impoverished local communities, it incentivises the conservation of natural areas that might otherwise be destroyed by agriculture and infrastructure projects. 

Gelada Monkey in the Simien Mountains

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