Eastern Lowland Gorillas

Where they live: Democratic Republic of Congo

Characteristics:

Eastern lowland gorillas are the largest subspecies of gorilla, and adult males can reach up to 250kg (39st 5lb), making them the world’s largest primate. They are similar to mountain gorillas but can be distinguished by shorter fur, narrower faces and rounder nostrils.

Eastern lowland gorillas, in common with other subspecies of gorilla, are largely herbivorous but have been observed eating ants and other insects. They live in family groups led by the dominant male silverback, and during the day spend their time feeding and resting. Gorillas build new nests to sleep in every night.

Behavior

Eastern lowland gorillas tend to be sociable and very peaceful, living in groups of 5 to 30. A group usually consists of one silverback and few subdominant males. Silverbacks are the strong, dominant troop leaders. They are in charge of leading the group to food and protecting the group from danger. Males will slowly begin to leave their original group when they reach maturity, usually traveling with a group of other males for a few years before being able to attract females to form a new group.

Reproduction

A female will give birth to twins or a single infant after a gestation period of about 8½ months. They breastfeed for about 12 months. The baby can crawl at around 9 weeks old and can walk at about 35 weeks old. Infant gorillas normally stay with their mother for 3 to 4 years and mature at around 11 to 12 years old.

The scientific classification: Kingdom: Animalia, Phylum: Chordata, Class: Mammalia, Order: Primates, Family: Hominidae, Genus: Gorilla, Species: Gorilla. Beringei, Subspecies: Gorilla. Berengei. Graueri.

The eastern lowland gorilla (Gorilla beringei graueri) is a subspecies of eastern gorilla that is now only found in the forests of eastern Democratic Republic of the Congo. Many live within the boundaries of Kahuzi-Biega National Park.

This subspecies is considerably larger and more robust in appearance than the western lowland gorilla, having a longer body, longer teeth, a stronger jaw and a broader torso. They have black coats which in males, like other gorillas, turns silver at the back as the animal mature. There are many more western lowland gorillas than the eastern variety; compared to a possible total of over 100,000 western lowland gorillas, there are only about 4,000 eastern lowland gorillas in the wild and only 1 female in captivity at the Antwerp Zoo in Belgium.

Physical description

The eastern lowland gorilla is the largest subspecies of gorilla and the largest living primate. The maximum size of a male eastern lowland gorilla can be over 250 kilograms (550 lb) and when standing fully erect over 2 meters (6.6 ft) in the wild, with much heavier weights recorded in captivity. Some males are recorded to have weighed 275 kg (610 lb), 287 kg (630 lb), 312 kg (690 lb), 318 kg (700 lb) and 338 kg (750 lb). The record weight belongs to a male named Phil, who weighed 388 kilograms (860 lb) and lived between 1941 and 1958 at the St. Louis Zoo. Phil’s measurements were: height 1.7 meters (5.6 ft), bust 182 centimeters (72 in), neck 91.5 centimeters (36.0 in) and wrist 38 centimeters (15 in). He was weighed on a verified weight after an eight-week-long diet. According to the late John Aspinall, a 550 lb (250 kg) male eastern lowland gorilla in his prime has the combined strength of 7–8 heavyweight Olympic weightlifters.

Habitat and ecology

Eastern lowland gorillas are predominantly herbivorous, eating mostly leaves. They are known to eat only a few leaves from a single plant, allowing the plant to re grow. They will also eat fruit, seeds, bamboo shoots and insects. Gorillas also engage in coprophagia; they eat their own feces, as well as the feces of other gorillas. Similar behavior has also been observed among chimpanzees. Such behavior may serve to improve absorption of vitamins or of nutritive elements made available from the re-ingestion of seeds.

Conservation and threats

The lowland Gorillas are threatened by Coltan mining which increased after the cell phone boom.

Mount Tshiaberimu gorillas

In 1996 a small isolated population of gorillas was found living at Mount Tshiaberimu, a small isolated annex in the northern region of the Virunga National Park. The population was facing imminent extinction, threatened by activities such as mining, hunting and the collection of firewood. In rapid decline and ignored by many, the Gorilla Organization pledged to protect this tiny group of gorillas and the habitat.

The Mt Tshiaberimu gorillas are morphologically different to the Eastern Lowland gorillas found elsewhere and may yet be reclassified as a distinct subspecies, Gorilla beringei rex-pygmaeorum. They are currently officially classified as Gorilla beringei graueri.