A mountain gorilla family is led by a dominant silverback, who protects the group and decides where it moves. Adult females raise the infants. Younger males, called blackbacks, may stay or leave, and females often move between groups. Most groups number around ten animals, and some have more than one silverback.
Table of Contents
- Meet the family
- The silverback
- Displays and communication
- Females and infants
- Blackbacks and young males
- How groups form and change
- A typical day
- Reading behaviour on your trek
- What this means for conservation
- Choosing a family to visit
- When leadership changes
- Friendship, play and learning
- What gorillas eat
- Sizes of families you may meet
- Frequently Asked Questions
Meet the family
When you trek to see gorillas in Rwanda, you do not meet a random collection of animals. You meet a family, with a leader, mothers, infants and older offspring, all known to the trackers by name. Understanding who is who makes the hour far more rewarding.
This article explains the roles inside a mountain gorilla group and how groups change over time. To see one for yourself, our gorilla trekking in Rwanda page explains how a visit is arranged.
The silverback
The silverback is the adult male who leads the group. He gets his name from the band of silver hair that appears across his back once he matures, at around twelve years old or more. He is much larger than the females, and can weigh well over twice as much.
His job is protection and decision-making. He decides when the group feeds, rests and moves, and he defends it from rival males and other threats. He also settles disputes between group members. Strength alone is not what makes a good leader: a calm silverback who keeps the peace often holds a group together for many years.
Displays and communication
Silverbacks are known for chest-beating, but the drumming is mostly a display of size and a way of communicating. It is usually not aggression. Gorillas also use a rich set of sounds, from soft rumbles that mean contentment to barks and roars that signal alarm.
Your guide will know the family's sounds and will explain them as you go. A steady, low rumble is a sign of a relaxed group. A sudden series of hoots and beats is usually a warning, and your guide will move you back if needed. Our gorilla trekking rules and etiquette guide explains what to do if that happens.
Females and infants
Adult females form the core of the group. They give birth roughly every four years or so, carry a single infant at a time, and nurse it for several years. The mother is the centre of an infant's world in its first few years, and other members of the group take an interest in it as it grows.
Infants ride on their mother's back or stay close to her. Playtime is the reason many visitors remember the hour: young gorillas tumble, climb and chase each other, and sometimes come closer than you would expect. Even then, guides ask visitors to keep their distance and let the animals decide.
Blackbacks and young males
Males between about eight and twelve are called blackbacks, because their backs are still dark. They are stronger than females, but not yet fully grown. Some stay with the group they were born in, and help defend it. Others leave to start their own group.
In some groups, more than one silverback lives together. This is more common among the Virunga gorillas than in many other populations, and it shapes how the group behaves. A group with several males may be more stable, but tension between rivals is normal. Our article on types of gorillas puts the mountain gorilla in context with its relatives.
How groups form and change
Gorilla groups do not stay fixed. Young females usually leave the group they were born in when they reach maturity, and join another silverback or a lone male. Young males may leave to travel alone, and later attract females to start a new group.
Groups can also split or merge, and the loss of a silverback can change everything. Without a leader, the remaining members may disperse or join another group. This is part of why researchers keep such careful records, which you can read about in our piece on Karisoke and the research camp.
A typical day
| Time | What the family does |
|---|---|
| Early morning | Wake from night nests, begin feeding |
| Mid morning | Move through the forest, feeding on leaves, stems and bamboo shoots |
| Midday | Rest, groom and play |
| Afternoon | Feed again, then move to a new area |
| Evening | Build fresh nests on the ground or in low vegetation and settle |
Gorillas spend a large part of their day eating. They mostly eat plants, including leaves, stems, roots and shoots. They rarely drink, getting most of their water from their food. Each night they build a new nest, so the forest floor of a family's range is dotted with old ones.
Reading behaviour on your trek
On your visit, watch for the small things:
- A silverback staying at the edge of the group, watching. He is scanning for threats.
- A mother holding an infant close, or a youngster wandering away and being called back.
- Grooming, which reinforces bonds between animals.
- Play between infants and juveniles, which is how they learn.
Guides will point these out. They know each family's history, including who has left or joined, and often who is related to whom. Our article on the gorilla families of Volcanoes National Park introduces the groups you may be assigned.
Ask your guide to tell you the family's story before you start walking. Knowing who the silverback is and how the group formed makes the hour much richer.
What this means for conservation
Family structure matters for protection. Because groups are tightly bonded, the death of a key animal can affect everyone in the family. Infants that lose their mothers are at risk, and a new silverback taking over a group can change who survives.
That is one reason trackers monitor each group daily, and why conservation depends on knowing individuals. The story of how this system developed is in how Rwanda saved the mountain gorilla.
Choosing a family to visit
Groups differ in size, location and the difficulty of the trek to reach them. Some are close to the park boundary, and others are high on the volcano. Your operator can ask for a family that suits your fitness level, although the park makes the final decision on allocation.
Our 3-day gorilla trekking itinerary is a good structure for a first visit, with time on either side of the trek so that a hard or wet day does not overwhelm your plans.
When leadership changes
A silverback does not lead forever. As he ages, a younger male may challenge him, and the group can pass from one to another. In some groups, a younger silverback takes over gradually, with the older male staying on in a smaller role. In others, the change is sudden and follows a fight.
When a silverback dies, the group may break apart. Females may join other groups, and young males may leave. Infants are most at risk during these changes, because a new male sometimes does not tolerate the offspring of a rival. Researchers have recorded this behaviour, and it is one reason conservationists pay close attention to the survival of dominant males.
Friendship, play and learning
Gorilla groups are affectionate places. Adults groom one another, and youngsters spend hours in play that looks a lot like human children's games: wrestling, chasing, swinging and mock fights. Play is how they practise skills they will need as adults, such as how to read another animal's mood.
Young gorillas also learn what to eat by watching their mothers. Diet in the forest is varied and includes some plants that are hard to process, so knowledge passed within the family matters. That is another reason each animal's loss is felt by the rest of the group.
What gorillas eat
The main foods are leaves, stems and shoots, with fruit when available. Bamboo shoots are a seasonal favourite in the Virunga area, and the gorillas may spend days in bamboo forest when the shoots are fresh. Adults eat large amounts each day, because plant food is low in energy.
Because they eat so much, gorillas leave clear signs: broken stems, stripped bark, trampled patches and droppings. Trackers use these signs to follow a group from one day to the next. Ask your guide to point some out as you walk.
Sizes of families you may meet
Group sizes vary widely, and the park allocates visitors to families based on availability. Some families are small and quiet, while others are larger and more active, with several infants.
| Family type | What you may see |
|---|---|
| Small group with one silverback | Calm, easy to follow the family's roles |
| Large group with several males | More interaction, some tension between males |
| Group with young infants | Frequent play and close contact with mothers |
Frequently Asked Questions
Who leads a gorilla family?
An adult male called a silverback leads. He protects the group, decides where it goes and keeps order among its members.
Why are they called silverbacks?
A saddle of silver-grey hair appears across a male's back as he matures. It marks him as a fully grown adult, usually from around twelve years old.
Do female gorillas stay in the same group?
Often not. Many young females leave the group where they were born and join another. This helps prevent inbreeding and keeps groups genetically varied.
How many gorillas are in a family?
Group sizes vary, but around ten is common. Some groups are much smaller and some considerably larger. The number changes with births, deaths and departures.
Can there be more than one silverback in a group?
Yes. Multi-male groups are common among mountain gorillas in the Virunga area, and they usually work through a clear hierarchy.