Gorillas are the largest of the great apes. Although they’re over 10 times stronger than humans, they share 98.3% of their DNA with us—making the gorilla our closest cousin after chimpanzees and bonobos.
There are only two types of gorillas in the world, eastern and western, and they’re actually next-door neighbours, separated by just 560 miles of forest. These two types are divided into two subspecies: eastern lowland gorillas, eastern mountain gorillas, western lowland gorillas, and western Cross River gorillas.
Gorillas are social animals and live in family groups called troops. The average troop size is around five to 10 gorillas but some can contain more than 50 individuals. The groups are polygamous, with one adult male gorilla, known as a silverback, leading the troop and mating with the female members. The young remain with the troop until they mature, at which point all of the males and around 60% of the females move to new troops to prevent inbreeding.
Gorillas reproduce similarly to humans: the female is fertile for a couple of days every month, gestates for around eight to nine months, gives birth to (usually) one infant at a time, and nurtures them for multiple years before becoming pregnant again. Generally, females reproduce just once every four to six years, which makes it very difficult for gorillas to recover from a population decrease.
Another similarity between gorillas and humans is emotional experience. Like us, gorillas express a range of emotions, from laughing during play to grieving for the dead. Communication between gorillas involves a range of vocalisations, including grunts, barks, whimpers, whines, and chuckles, as well as hoots, roars, and screams.
They’re also highly intelligent creatures and have been witnessed using a range of tools, from sticks to measure the depths of rivers, to twigs for scooping up food. They also make ladders from bamboo to help their young climb trees.
Due to their foraging habits, gorillas play a vital role in the health of forests. By consuming plants and fruits and then moving on to new locations, they help spread seeds with their faeces and allow vegetation to thrive. Their extreme strength is also useful for pulling apart vegetation, like banana trees, to access food. This behaviour also helps other species find food and shelter and lets in sunlight to help keep forests healthy.
What is a gorilla's scientific name?
The scientific name for the eastern gorilla is Gorilla beringei, and the western gorilla’s is Gorilla gorilla.
The name “gorilla” comes from an account by Carthaginian navigator Hanno of his expedition down the western coast of Africa nearly 2,500 years ago. According to the account, he encountered the primates during his travels, and his interpreters translated the local name into Ancient Greek as gorillai.
In English, a rough translation might be “hairy person.” It’s uncertain whether this account is true or not, but it was known to American naturalist Thomas S. Savage when he scientifically described the species for the first time in the 1840s, leading him to choose the name “gorilla.”
Are gorillas endangered?
Unfortunately, both the eastern and western gorillas are classified as critically endangered by the IUCN. For eastern gorillas, the number of mature individuals has decreased to just 2,600.
Both species face similar threats, including human interference through agriculture, mining, transportation corridors, and poaching. Invasive diseases and loss of habitat are also significant factors in their population decrease.
Where do gorillas live?
The two types of gorillas live on opposite sides of the Republic of the Congo, separated by the Congo basin forest. The eastern gorillas are found in Rwanda, Uganda, and the Republic of the Congo. Western gorillas live in Angola, Cameroon, Central African Republic, the Democratic Republic of the Congo, Equatorial Guinea, Gabon, and Nigeria.
Both species live in forests and build nests to sleep in each night, mostly on the ground but sometimes in trees. The mountain subspecies both live at greater elevations, generally above 1,400 metres, in mixed forests, bamboo forests, and subalpine grasslands. Gorillas are not territorial, and different family groups often live in overlapping areas.
The main threats to gorillas are habitat loss, bushmeat hunting, and diseases carried by the hunting trade. The slow reproduction of gorillas is a key reason why these threats are so dangerous to the population.
Agricultural activities in central Africa, along with illegal mining and oil palm plantations are causing destruction and fragmenting gorilla habitats. Mountain gorillas are being pushed to greater elevations due to human occupation at lower levels. This trend is expected to continue, as 73.8% of western gorilla habitat is considered suitable for oil-palm plantations and may be used in the future.
Hunting for bushmeat
Bushmeat refers most commonly to forest wildlife in Africa hunted for human consumption. Ape meat and other kinds of bushmeat are considered status symbols in the urban centres of Africa, and the demand for it is one of the most urgent threats to gorillas today. Even when hunters aren’t targeting gorillas, they can get caught in traps laid for other animals and die from entanglement or starvation.
Current hunting levels of gorillas are unsustainable—if they continue at this rate, they will kill the gorillas faster than they can reproduce and replenish their numbers, leading to extinction. Projections suggest complete extinction could happen in just five to 15 years.
A severe and tragic side effect of the hunting trade is the transmission of disease. Because gorillas have similar DNA to humans, they are susceptible to many of the same diseases but have no developed immunity or medicine to combat them. The Ebola virus has been the leading lethal disease among gorillas in recent years. In 2002, an outbreak caused the deaths of eight gorilla groups that researchers had been following and studying since 1994.
Other human diseases that can infect great apes include Hepatitis A, poliovirus, tapeworm, and tuberculosis bacillus—all of which can survive in the soil for six months.
What do gorillas eat?
Gorillas are primarily vegetarians, and their exact diets depend on the area in which they live and the season. For example, mountain gorillas live in bamboo forests and, during the young bamboo season, will live almost entirely off young bamboo shoots.
Some subspecies, such as western lowland gorillas, mountain gorillas, and cross river gorillas, also eat invertebrates, like ants, snails, grubs, termites, and caterpillars.
Foods that all gorillas can eat year-round include leaves, fruits, stems, roots, vines, herbs, tree bark, and grasses. An adult male can consume over 18 kilograms of food per day, which takes up most of his waking hours. All of this vegetation has such high moisture content that gorillas rarely need to drink.
How strong is a gorilla?
Silverback males are around double the size and weight of females and more than 10 times stronger than humans. They can tear down banana trees and bend iron bars.
How long do gorillas live?
In the wild, the average lifespan for a gorilla is around 35 years, but they can live as long as 50 years.
How much does a gorilla weigh?
Adult males can weigh up to 200 kilograms and reach 182 centimetres in height. Females weigh around 90 kilograms and stand as tall as 150 centimetres.
Can gorillas swim?
Gorillas can’t swim naturally and often avoid large bodies of water. They sometimes use sticks to measure the depth of rivers to make sure they’re safe to wade across. When caught in a sudden shower, it’s common for gorillas to sit still and wait it out or take shelter in a nearby cave.
Why do gorillas beat their chests?
Although little is known about this famous behaviour, recent studies suggest it warns off potential competitors. Since gorillas aren’t territorial, troops are often within short distances of each other and silverbacks can challenge the dominance of another troop leader.
After more than 3,000 hours of observation and sound recording, a study led by Edward Wright suggested that the biggest gorillas produce the sounds with the lowest frequencies when beating their chests. This could mean the behaviour is used to prove and communicate their size to surrounding males and warn them to think again about issuing a challenge.
How fast can a gorilla run?
Gorillas run using both their legs and their arms, and they have been recorded running at speeds of 25 miles per hour in their forest habitats. For reference, the average male human runs at eight miles per hour, and the record set by Usain Bolt is 27.8 miles per hour.
How closely are gorillas and humans related?
Gorillas are not as closely related to humans as chimpanzees or bonobos, but it is thought that we share a common ancestor who lived around 10 million years ago. Today, gorillas share 98.3% of their DNA with humans, compared to the 98.8% humans share with chimpanzees and 98.7% with bonobos.
How many gorillas are left in the world?
Both species of gorilla are on the IUCN red list as critically endangered, meaning their populations are currently decreasing. The organisation reports around 2,600 mature individuals in the eastern gorilla species and a total number under 5,000. There are an estimated 100,000 western gorillas.
How can you help?
Gorillas are critically endangered due to the growing threats they face, which include habitat loss, conflict with humans, and the spread of invasive diseases.