Eastern gorillas

What is an eastern gorilla?

Eastern gorillas are a critically endangered great ape species found in the heart of Africa’s forests. Eastern gorillas can be divided into two subspecies—the eastern lowland gorilla (Gorilla beringei graueri) and the mountain gorilla (Gorilla beringei beringei). The eastern lowland gorilla is also called Grauer’s gorilla, especially among scientists.

Eastern lowland gorillas, or Grauer’s gorillas, are only found in the main tropical rainforest of the Democratic Republic of Congo. Here, they’re found in Kahuzi-Biega and Maiko National Parks, though much of their range encompasses unprotected forest areas.

As their name would suggest, mountain gorillas live in the mountains. The mountain gorilla subspecies is restricted to two separate areas of Afromontane forest—the Bwindi Impenetrable National Park in southwestern Uganda and Virunga Massif, a volcanic mountain range spanning the Democratic Republic of Congo, Rwanda, and Uganda.

Gorillas are one of humans’ closest genetic relatives, descending from a common ancestor 10 million years ago. Analysis of the gorilla genome found that gorillas share more than 96% of their genes with humans. Gorillas bear some physical and behavioural resemblance to humans. They have been observed to display various emotions, from laughing and playing to crying and grieving.

Eastern gorillas are particularly social creatures, living in groups known as troops or bands. These groups are usually led by a dominant alpha male called a silverback gorilla. Troop sizes can range from a few individuals to 30 eastern gorillas. The troops comprise the lead silverback, female gorillas, their offspring, and some younger, subordinate males. Eastern gorillas form strong social and familial bonds within their troops through grooming, play, and communication via complex vocalisations and body language.

Gorillas don’t have a fixed breeding season. Females give birth to a single offspring once every four years, after a gestation period of approximately eight and a half months. On rare occasions, they may give birth to twins. Newborn gorillas weigh only around two kilograms (4.4 pounds). Baby gorillas are vulnerable and carried around in their mother’s arms during their first three months. Young gorillas are similar to human children and exhibit playful behaviour, like chasing one another and swinging from trees.

At age 10, female gorillas reach sexual maturity. Once they’ve reached this milestone, they will either move into another troop or find a lone silverback. While males do reach sexual maturity slightly earlier at age 9, they usually won’t reproduce until they reach 12 or 15 years old. They will go on to leave their group and seek out females to form their own troops. This can sometimes result in aggression—young males will attempt to remove females from their existing troops—and the death of infants. Some males will stay in their original family troops and take on the role of the silverback upon the death or incapacity of the father. Wild gorillas can live up to 35 years old. In captivity, some gorillas can live past 40 years old.

Both the eastern lowland gorilla and the mountain gorilla have robust, muscular bodies, with strong chests and protruding abdomens. Their black skin is covered in coarse, dark fur that helps protect them from the elements of their forest habitats. This fur covers everything except for their faces, hands, and feet, plus the chests of older males.

Mountain gorillas tend to have longer hair than Grauer’s gorillas, which helps them in colder, harsher mountain climates. Eastern gorillas are usually larger than other gorilla species, though they have slightly shorter arms. Generally, a gorilla’s arms are 15 to 20% longer than their legs. Adult male eastern gorillas are larger than adult females, weighing between 135 and 220 kilograms (300-485 pounds). Females are about half that weight at 70 to 90 kilograms (154-198 pounds). Males typically grow to 1.7 metres (5.5 feet) tall, while females are slightly shorter at 1.5 metres (4.9 feet).

Gorillas walk around on all fours in a knuckle-walking movement, using their hands’ knuckles to support their weight. Every now and then, gorillas will stand upright, though it’s usually in a display of dominance. While females and children have been observed to climb trees, the sheer weight of males means that they cannot climb as easily.

Eastern gorillas are usually gentle, non-aggressive animals. They are primarily herbivores with a diet of herbs, leaves, bark, vines, bamboo and fruit. Sometimes, they’ll also eat insects. Both subspecies spend much of their day foraging for food in dense tangles of forest growth.

Grauer’s gorillas and mountain gorillas are both important contributors to their forest ecosystems. Their feeding habits help disperse seeds, contributing to the biodiversity of their forest habitats. Gorillas also prune plants, which helps encourage plant growth. It also opens up spaces within the forest, allowing sunlight to nourish the rest of the plants. Maintaining the health of this ecosystem is crucial to maintaining the overall health of our planet, as forests serve as carbon sinks, absorbing and storing vast amounts of carbon dioxide.

What is an eastern gorilla’s scientific name?

The scientific name for an eastern gorilla is Gorilla beringei. This species comprises two subspecies—the eastern lowland gorilla, scientifically known as Gorilla beringei graueri, and the Mountain gorilla, scientifically known as Gorilla beringei beringei.

The eastern lowland gorilla is also called Grauer’s gorilla, named after Rudolf Grauer, the Austrian zoologist and explorer who first observed them as a separate subspecies.

Are eastern gorillas endangered?

The IUCN Red List classifies eastern gorillas as critically endangered, with 2,600 mature individuals left in the wild.

The mountain gorilla, a subspecies of eastern gorillas, is endangered, with a population of 600.

The eastern lowland gorilla—another subspecies—is critically endangered and has a decreasing population. While the exact number of individuals is unknown, in 2015, roughly 3,800 individuals remained. From 2015 to 1994, they experienced a population decrease of at least 77%.

Where do eastern gorillas live?

Eastern gorillas are found in East and Central Africa.

Mountain gorillas inhabit Virunga Massif, a chain of volcanic mountains that spans Rwanda, Uganda, and the Democratic Republic of Congo. Here, they’re found at an altitude of 1.85 kilometres (1.1 miles) or higher. They are also found at an altitude of 1.4 kilometres (0.86 miles) or above in the Bwindi Impenetrable Forest in Uganda.

Grauer’s gorillas (also called eastern lowland gorillas) live in the lowland tropical forests of eastern Democratic Republic of Congo. These forests are part of the Congo Basin, one of the world’s most significant tropical rainforest regions.