Gorilla

Gorillas are large, herbivorous great apes that live in the tropical forests of equatorial Africa. They belong to the genus Gorilla and have two species: the eastern gorilla and the western gorilla.

Gorillas are the largest living primates. They can be between 1.25 and 1.8 m tall (about 4 ft 1 in to 5 ft 11 in) and weigh from 68 to 227 kg (150 to 500 lb). They live in groups led by a silverback male. Eastern gorillas have darker fur than western gorillas.

Their homes are tropical or subtropical forests in Sub-Saharan Africa. Some live near sea level, while others live in high mountains. There are fewer gorillas now because of threats like losing their homes and disease, but efforts to protect them are helping.

History and etymology

The word gorilla comes from stories about an explorer named Hanno the Navigator. He lived around 500 BC and came from Carthage. He traveled along the African coast near what is now Sierra Leone. His team saw people with hairy bodies and called them Gorillae. We do not know if these were gorillas, another type of ape, or even humans.

Later, in 1847, two scientists, Thomas Staughton Savage and Jeffries Wyman, officially named the western gorilla. They saw specimens from Liberia. They used the name Troglodytes gorilla, which came from an ancient word for “hairy women.”

Evolution and classification

Gorillas are closely related to chimpanzees and humans. They split from a common ancestor about 7 million years ago. Their DNA is very similar to ours, differing by only about 1.6%.

Gorillas were once thought to be one species with three subspecies. Now, scientists agree there are two species, each with two subspecies. These species developed separately during the Ice Age when their forest homes became isolated. Researchers continue to study the relationships between different gorilla groups. One group, called the Bwindi gorilla, may be a third subspecies, but this is still being studied. Differences such as size, hair color, and facial features help scientists classify gorillas.

Characteristics

Wild male gorillas are large. They weigh between 136 to 227 kg (300 to 500 lb) and stand between 1.4 to 1.8 m (4 ft 7 in to 5 ft 11 in) tall. Females are smaller. They weigh 68–113 kg (150–250 lb) and reach heights of 1.25 to 1.5 m (4 ft 1 in to 4 ft 11 in). Adult males, called silverbacks, have a patch of silver hair on their backs.

Gorillas come in different types. The eastern gorilla is darker and has thicker hair than the western gorilla. They have dark brown eyes and move mainly by walking on their knuckles. They can also stand upright for short periods. Gorillas share many traits with humans, including fingerprints. They can live up to 40 years in the wild, though some zoo gorillas have lived longer.

Distribution and habitat

Gorillas live in the tropical forests of equatorial Africa. The two species of gorillas are separated by the Congo River and its tributaries. The western gorilla lives in west central Africa, while the eastern gorilla lives in east central Africa.

Gorillas can be found in many different habitats, from montane forest to swampland. Eastern gorillas live in forests that are high up in the mountains, while western gorillas live in both lowland swamp forests and montane forests. These great apes adapt well to many environments across Africa.

Ecology

Gorillas spend their days resting, moving around, and eating. Mountain gorillas eat mostly leaves, stems, and shoots. Eastern lowland gorillas eat more fruit and insects. Western lowland gorillas eat a lot of fruit and travel far each day to find it. Sometimes, gorillas climb trees to find food, especially leaves.

Each night, gorillas build simple nests from branches and leaves to sleep in. These nests are usually on the ground. Young gorillas stay close to their mothers until they are old enough to build their own nests. A silverback gorilla will protect its group from danger, even if it means putting itself at risk.

Behaviour

Gorillas live in groups called troops. These groups usually have one adult male, called a silverback, with several adult females and their young. Sometimes, there are more males in a group. The silverback gets his name from the silver hair on his back that appears when he grows up. He leads the group, makes decisions, and keeps everyone safe.

Females become mature at around 10 to 12 years old, and males at 11 to 13 years. Gorilla mothers take good care of their babies for the first few years. Babies stay close to their mothers for about five months and then spend more time away as they get older. Gorillas talk to each other using different sounds, like grunts, barks, and roars. These sounds help them share feelings, warn of danger, or show they are happy.

Intelligence

Further information: Primate cognition

See also: Great ape language

Gorillas are very smart. Some gorillas in zoos have learned to use sign language, like Koko. They can laugh, feel sad, and form strong family ties. They can also think about the past and future.

Further information: Tool use by animals § Gorillas

Scientists found that gorillas can use tools, like other great apes. In 2005, a female gorilla in the Nouabalé-Ndoki National Park in the Republic of Congo used a stick to check how deep the water was. Another gorilla used a tree stump to cross water and catch food. Even a young gorilla was seen using rocks to crack open nuts. This shows how clever gorillas are.

Scientific study

American doctor Thomas Staughton Savage collected the first gorilla bones when he was in Liberia. In 1847, he and a scientist named Jeffries Wyman wrote the first description of gorillas, naming them Troglodytes gorilla. We now call them the western gorilla.

Later, an explorer named Paul Du Chaillu was the first person from Europe to see a live gorilla in Africa between 1856 and 1859. He brought gorilla specimens to the UK in 1861.

Serious science about gorillas started in the 1920s. Carl Akeley from the American Museum of Natural History went to Africa to study and protect gorillas. After World War II, a researcher named George Schaller did the first careful study of mountain gorillas where they live. Later, Dian Fossey did a lot of research that helped clear up many old mistakes about gorillas.

Genome sequencing

Gorillas were one of the last great apes to have their genes studied. Scientists looked at the DNA of a female western lowland gorilla named Kamilah. This helped us learn more about how humans evolved. Even though chimpanzees are our closest living relatives, 15% of human DNA is more like gorilla DNA. The study also showed that changes in genes related to hearing, which were thought to be linked to human language, also happened in gorillas.

Captivity

Gorillas have been kept in western zoos since the 1800s. The care of these gorillas got much better in the late 1920s. Colo of the Columbus Zoo and Aquarium was the first gorilla born in captivity.

Zoos help gorillas feel calmer by using privacy screens and natural sounds instead of loud music. These changes help gorillas feel less stressed. Scientists think it's important to think about each gorilla's age and personality to keep them healthy.

Conservation status

All gorilla species and subspecies are endangered or critically endangered. They are protected by international laws to stop trading and hunting. There are many western lowland gorillas in the wild, and some eastern lowland and mountain gorillas.

Gorillas face threats like habitat destruction and diseases. Conservation efforts work to protect their homes and stop hunting.

Cultural significance

In parts of Cameroon, such as the Lebialem highlands, local traditions say a person's life is linked to a gorilla through totems. Many indigenous groups know a lot about gorillas. The Baka people, for example, have special names for different types of gorillas.

Gorillas appear in many stories, movies, and games. Early films sometimes showed them as scary, but newer stories, like Gorillas in the Mist, show them in a kinder way. They are characters in comics, cartoons, and video games, such as Donkey Kong.