Gelada

The gelada is found in Africa, especially in Ethiopia. Almost the entire population lives on the Ethiopian plateaus of the Simien National Park, between 1,500 and 4,500 m in altitude. There, it lives in vast grassy meadows surrounded by cliffs and rocky valleys.

Reproduction can happen all year round. After a gestation period of 5 to 6 months, the single baby, weighing 400 grams, remains attached to its mother’s belly during the first weeks of life. The young become independent at about one year of age. Females mature at 3 years old, while males mature between 4 and 5 years. However, they only reproduce around 8 or 10 years of age due to social constraints. These young solitary males form bachelor groups on the periphery of harems. Females, on the other hand, remain within their natal group throughout their lives.

When a solitary male and a harem male fight to acquire or preserve the position of “boss”, it is ultimately the females who choose with whom they form the harem, regardless of the outcome of the fight. Winner or not, the male who has not gained the favor of the females can even be chased away by them.

They are the most specialized terrestrial primates in terms of diet as they feed exclusively on grasses. They can enjoy the flowers, seeds, roots, and stems. The percentage of these different food resources they ingest varies greatly depending on the seasons. During drier periods, as grass becomes more scarce, they favor rhizomes and roots, which make up 70% of their diet. In contrast, during the rainy season, 93% of their food consists of grass blades.

Thanks to their short fingers and especially their opposable thumbs, they have great manual dexterity, allowing them to easily grasp seeds or a single blade of grass selected from among others.

During the day, geladas roam the high plateaus in search of food and spend almost all of their time doing so. They are terrestrial and do not climb trees, but once night falls, they climb cliffs to sleep in crevices in the rock face. This way they stay safe from predators like leopards or hyenas.

Geladas live in large groups composed of between a dozen to a hundred individuals. These groups, called “bands,” are subdivided into harems made up of a dominant male, called “the boss,” several females, and their young.

The gelada is one of the only primates, along with humans, able to smack its lips and synchronize lip and tongue movements. This allows them to have a very complex language, sometimes similar to human language. Nearly 28 different sounds have been identified. That’s why this species is widely studied to understand the emergence of language in humans.

This very complex communication system is complemented by gestures and facial expressions. For example, lifting the lips to expose the teeth is a sign of appeasement or a way to greet each other.

The predators of the gelada are panthers, hyenas, foxes, and servals. But today, their greatest predator is none other than the domestic dog, which is increasingly present due to human expansion.

To date, the gelada is not a threatened species. It is still widely present across almost its entire geographic range. However, its populations are declining. Ethiopia, being the second most populous country in Africa, sees the gelada’s habitat slowly reduced and changed by agricultural expansion. Thus, it is only in the very high-altitude grasslands that it finds enough food.