Mountain Gorilla Facts: 25 Things Most Visitors Don't Know

Table of Contents

1. Why these facts matter
2. Numbers and status
3. Body and appearance
4. Family life
5. Diet and daily life
6. Behaviour and communication
7. Where the family groups live
8. What these facts mean on a trek
9. Planning your own trek
10. Myths worth dropping before you go
11. What to look for when you are there
12. Why gorillas are still at risk
13. Frequently Asked Questions

Why these facts matter

Most visitors know a few basics about mountain gorillas: they are big, they are gentle and they are endangered. The details are far more interesting, and knowing them changes what you notice on a trek. When you sit an hour with a gorilla family in the forest of Volcanoes National Park, small behaviours suddenly make sense.

Here are 25 facts, grouped by theme. Where a figure is a research estimate, it is marked as one. If you are planning a trek, our gorilla trekking in Rwanda page explains how the experience works.

Numbers and status

1. Mountain gorillas are a subspecies of the eastern gorilla, and they live in only two places on earth: the Virunga Massif, which spans Rwanda, Uganda and DR Congo, and Bwindi Impenetrable National Park in Uganda.
2. The total population is a little over a thousand animals, according to the most recent surveys. That is a small number for any large mammal.
3. Mountain gorillas were listed as critically endangered for many years. Conservation work has since improved their status to endangered, one of the few great ape success stories.
4. The Virunga population is monitored closely by park teams, and each habituated family is tracked daily.
5. The population has grown thanks to anti-poaching patrols, veterinary care, community programmes and tourism revenue. Our story on how Rwanda saved the mountain gorilla tells that history.

Body and appearance

1. Adult males are larger than females and can weigh well over 150 kilograms. Females are considerably lighter.
2. Males develop a band of silver hair across the back at around twelve years old, which is why the dominant male is called a silverback.
3. Mountain gorillas have longer, thicker fur than other gorillas, which helps them in cold, wet mountain forest at high altitude.
4. Every gorilla has a unique nose print, the pattern of wrinkles above the nostrils. Researchers and trackers use it to identify individuals, much like a fingerprint.
5. They walk on their knuckles, with their arms longer than their legs, and can stand upright briefly when displaying or looking around.

Family life

1. A gorilla family is led by a dominant silverback, who protects the group, decides where it travels and settles disputes. Our article on how a gorilla family works explains the roles in detail.
2. Groups often contain around ten members, though sizes vary from a handful to several dozen.
3. Females usually leave the group they were born in when they mature and join another male's group or a lone silverback. This helps prevent inbreeding.
4. A female gives birth roughly every four years, usually to a single infant, after a pregnancy of around eight and a half months.
5. Infants cling to their mothers for months, ride on her back as they grow and stay close for several years. Play is constant and often noisy.

Diet and daily life

1. Mountain gorillas are mostly herbivores. They eat leaves, stems, shoots, roots and bamboo, and they occasionally eat fruit and insects such as ants.
2. Adults eat huge quantities of plants each day, which is why they spend much of the day feeding.
3. They rarely need to drink because their food is rich in water.
4. Each night they build a fresh nest of leaves and branches on the ground or in low trees. Infants share their mother's nest.
5. A typical day involves feeding in the morning, a rest through midday and more feeding later, moving slowly through their home range.

Behaviour and communication

1. Chest beating is a display, not a sign of aggression. Silverbacks use it to show size, and it is often followed by running and breaking vegetation.
2. Gorillas communicate with more than two dozen distinct sounds. Belch-like rumbles signal contentment and are often heard when a group is feeding calmly.
3. They are generally shy and non-aggressive. Conflicts usually end in displays rather than fights.
4. They live in cool, misty forest between roughly 2,200 and 4,000 metres above sea level.
5. Like humans, gorillas are susceptible to respiratory diseases, which is why trekkers must keep their distance and never approach when ill.

Where the family groups live

In Rwanda, trekking takes place in Volcanoes National Park, in the northwest, about a two-hour drive from Kigali. The park is home to a number of habituated families, each named and followed by trackers. Our guide to the gorilla families of Volcanoes National Park introduces them, and our Dian Fossey legacy article explains how the research began.

The research station she founded is still remembered in the park. Read Karisoke: inside Dian Fossey's research camp for the story.

What these facts mean on a trek

On a trek, you will be with a family for about an hour after the trackers find them. Knowing the facts helps you read the group. If the silverback is calm and eating, you can relax. If a young gorilla is playing, watch the mother. If you hear a low rumble, the group is content.

Follow the guide's rules on distance and quiet. Keep the required distance from the animals, avoid sudden moves and do not eat in front of them. If a gorilla approaches you, stay calm and move away slowly as your guide instructs.

Planning your own trek

A trek requires a permit, which is USD 1,500 per person as of this writing, and a reasonable level of fitness. Our gorilla trekking permit page explains how to book, and our 3-day gorilla trekking trip shows how it fits into a short stay.

Trekking rules include a minimum age and group size limits, and you must be healthy on the day. If you have a cold, tell your guide, because gorillas are vulnerable to human illness.

Myths worth dropping before you go

A few ideas travel with visitors that the forest quickly corrects.

Gorillas are not aggressive by nature. A silverback may charge, beat his chest or stare hard at you, but almost always this is communication, and your guide will already know how to respond. Stay low, look away and let the moment pass.

Gorillas are not smelly in a way that ruins the experience. You may notice a strong, musky scent near a silverback, which comes from glands under the arms and is strongest when he is excited. Most visitors barely register it.

You do not need to be an athlete. Treks vary a great deal in length and steepness, from under an hour to several hours each way. The trackers set out before you and the park assigns families with the fitness of the group in mind, so you can ask for an easier or harder allocation on the morning.

Gorillas do not mind being watched, within limits. The families in Volcanoes National Park are habituated, which means they have spent years getting used to a small number of quiet human observers. That process takes a long time, and it is the reason visits are strictly limited in group size and time.

What to look for when you are there

Once you are with a family, slow down and watch for these small things.

• Where the silverback sits. He is usually central, and the group arranges itself around him.
• How mothers hold infants. Very young gorillas are carried and checked constantly.
• Grooming. Adults spend long periods picking through each other's fur, which strengthens bonds.
• Food handling. Watch how a gorilla peels a celery-like stem with quick, precise hands.
• The young. Juveniles wrestle, climb and tumble, and they are usually the highlight of a visit.

Take your camera, but spend part of the hour with it down. Our guide to photographing mountain gorillas explains how to balance the two.

Why gorillas are still at risk

The population is growing but remains small and vulnerable. Threats include habitat pressure, disease and snares set for other animals. Our article on why mountain gorillas are endangered explains these threats and what is being done.

Your trek contributes directly to protection. Permit fees support park management and community projects. Our responsible tourism page explains how we plan trips that respect both wildlife and local communities.

Frequently Asked Questions

How many mountain gorillas are left?

A little over a thousand, according to recent surveys, split between the Virunga Massif and Bwindi in Uganda. Numbers are updated after each census, so check current figures.

What is a silverback?

A mature male gorilla, usually over about twelve years old, who develops a band of silver hair on his back. He leads the group and protects its members.

Are mountain gorillas dangerous?

They are powerful animals but generally peaceful. Incidents with visitors are rare, and you reduce risk by following your guide's instructions and keeping your distance.

What do mountain gorillas eat?

Mostly plants: leaves, stems, shoots, roots and bamboo. They eat occasional fruit and insects, and they get most of their water from their food.

How long do mountain gorillas live?

In the wild, many live into their thirties, and some longer. Exact ages are difficult to confirm because researchers track individuals over time.

Can children trek to see gorillas?

There is a minimum age for gorilla trekking, and rules apply. Check the current rule with your operator, and see our page on trekking for families before you plan.