Mountain Gorilla Conservation Fund


Questions about Gorillas

At the Mountain Gorilla Conservation Fund (MGCF), one of our most important tasks is helping people understand and appreciate one of our closest relatives in the animal kingdom, the mountain gorilla. MGCF is working with the Rwandan government to provide support for a broad range of solutions aimed at protecting both mountain gorillas and their habitat. We invite you to send an eMail to us asking about gorilla behavior, lifestyle, or habitat.

The following is a list of the most commonly asked questions.

Question 1. Where do the mountain gorillas live?

Mountain gorillas live in the Virunga volcanoes in East Central Africa. The majority of them exist on the slopes of the dormant volcanoes Karisimbi, Mikeno, and Visoke, Sabinyo, Mgahinga, and Muhavura. While the gorillas' habitat is mountainous, they rarely climb above 13,000 ft, and also seem to avoid the low, meadowy areas between the volcanoes. Because access to food plays a primary role in the gorillas' choice of habitat, they spend most of their time in the Hagenia forests, some of their time in the bamboo forests, and very infrequently visit subalpine areas.

Question 2. What is the greatest current threat to the Mountain Gorilla?

Less than 790 mountain gorillas currently exist. Many factors have contributed to their endangered status, including habitat loss, poaching, and snares meant for small game. Recently, mountain gorillas have also become the victims of neighboring human warfare.

An additional concern facing mountain gorillas is the possibility of declining genetic diversity. Mountain gorillas reproduce slowly: Females do not reach sexual maturity until their tenth year and reproduce only once every four to eight years, and males are not sexually active until they are fifteen. Further, only 50 percent of gorilla young survive their first year. As a result of their dwindling gene pool, mountain gorillas are faced with the common genetic problems that result from inbreeding. The greatest problem that mountain gorillas currently face, however, is human encroachment on their habitat.

Question 3. Are there other types of Gorillas?

The answer is yes. According to Carl Linnaeus's zoological classification system, humans, gorillas, chimpanzees, and orangutans all belong to the order of Primates. The gorilla group is further classified into three subspecies: (1) western lowland gorillas (Gorillas gorilla gorilla), (2) eastern lowland gorillas (Gorilla gorilla graueri), and (3) mountain gorillas (Gorilla gorilla beringei). The differences between the three gorilla subspecies are very minor, and primarily consist of small variations in size and coloring. Approximately 50,000 western lowland gorillas currently live in West Central Africa. In recent years, the eastern lowland gorilla population, which exists in the eastern Congolese rainforest, has significantly declined. In 1960, the eastern lowland gorilla population was estimated to range between 5,000 and 15,000. Presently, however, only about 2,500 live in the wild, while less than fifty reside within zoos. Mountain gorillas, who live in the Virunga mountains of East central Africa, are the most endangered of the three subspecies, and are seriously threatened by the possibility of extinction. There are only about 790 of them left in the world.

Question 4. How many gorillas are there in the world?

In comparison with other species, the number of gorillas in the world is relatively small, and is, unfortunately declining rather than increasing. All three gorilla subspecies are officially classified as endangered. Approximately 50,000 western lowland gorillas currently live in West Central Africa. In recent years, the eastern lowland gorilla population, which exists in the eastern Congolese rainforest, has significantly declined. In 1960, the eastern lowland gorilla population was estimated to range between 5,000 and 15,000. Presently, however, only about 2,500 live in the wild, while less than fifty reside within zoos. Mountain gorillas, who live in the Virunga mountains of East central Africa, are the most endangered of the three subspecies, and are seriously threatened by the possibility of extinction. There are around 790 of them left in the world, and none survive in captivity.

Question 5. How can I help protect the Mountain Gorilla from extinction?

You can learn more about this issue, and work to raise public awareness about the current situation of mountain gorillas. You can participated in one of our Gorilla Events or by making a general donation which help our project the most. You can become actively involved by volunteering at an organization devoted to this very important cause.

Question 6. Are mountain gorillas friendly?

While mountain gorillas are large, physically imposing creatures, they are also gentle, affectionate, and intelligent. Mountain gorillas are peaceful vegetarians who are devoted to their family groups. Mountain gorillas spend a large portion of their day interacting playfully with their young, and can be fiercely protective if their families are in danger. They only behave aggressively toward humans if they believe they are being threatened.

Question 7. Are mountain gorillas biologically similar to human beings?

Yes! Mountain gorillas are one of our closest relatives, sharing 98.6% of our genomes and 99.6% of our DNA. Humans and gorillas evolved from a common ancestor, and like human beings, mountain gorillas are intelligent, playful, emotional, and family-oriented. They are even capable of learning sign language. Despite our connections, however, human beings have been the mountain gorilla's only effective predators.

Question 8. Are Mountain Gorillas independent, or do they live in groups?

Mountain gorillas, like most primates, are highly social animals. They live in family groups of varying sizes, which consist of males, females, juveniles, and infants. The leader of each group is a dominant silverback, who is much larger than the other members. All members of the group defer to the dominant silverback, who acts as a protector, and directs the group as they forage for food.

By the time they are eleven, males typically leave their natal group; however, any attempt to join another established group would be viewed as threatening to that group's males. As a result, young adult males often spend lengthy periods in isolation, until they can attract females and establish their own group. At around eight years of age, females leave their natal group in order to join a new group before breeding.

Because they are sociable animals, gorillas try to protect one another from potential danger. Adult gorillas commonly risk their lives to defend their young from poachers and other dangers, and often die in the process. Like humans, gorillas grieve for their family members after they die. When the dominant silverback dies the family group can be deeply disrupted, and may even disperse into sub-groups.

Question 9. Would it be possible to see a Mountain Gorilla in a zoo?

It is impossible to see a mountain gorilla in a zoo because they cannot survive in captivity. The western lowland gorilla is the sub-species of gorilla most commonly seen in zoos, and approximately 50,000 of them currently live in West Central Africa. In recent years, the eastern lowland gorilla population, which exists in the eastern Congolese rainforest, has significantly declined. In 1960, the eastern lowland gorilla population was estimated to range between 5,000 and 15,000. Presently, however, only about 2,500 live in the wild, while less than fifty reside within zoos. Mountain gorillas, who live in the Virunga mountains of East central Africa, are the most endangered of the three subspecies, and are seriously threatened by the possibility of extinction. There are less than 790 of them left in the world, and they can only exist in the wild.

Question 10. What is a Mountain Gorilla's typical day like?

Gorillas spend about thirty percent of the day eating, thirty percent foraging and playing, and forty percent resting and sleeping in nests, which they have constructed. Gorillas live in small family groups, which usually consist of a dominant silverback, several females, and their offspring. While gorillas are generally peaceful, conflicts can sometimes occur when groups interact with each other, particularly if a solitary male contacts a new group.

Question 11. What type of food do mountain gorillas eat?

Primarily vegetarians, mountain gorillas eat many types of vegetation, including the stems, roots, leaves, and flowers of plants, and the bark of certain trees. Thistles, wild celery, bamboo shoots, and fruits are additional staples of the mountain gorilla's diet. Their primary habitat is the Hagenia forest, because most of the foods they eat are found there year-round. Because the growth of bamboo shoots is highly variable from year to year, and fresh shoots are only available between August and December, the bamboo forest is a secondary habitat for the gorillas.

Gorillas spend the majority of their time within the mountain forests and generally avoid the cultivated farmland that surrounds their habitat.

Question 12. What is the average life span of a mountain gorilla?

The average life span of mountain gorillas is difficult to estimate because they only exist in the wild. Their life span seems to range from thirty to thirty-five years.

Question 13. How many babies do female gorillas have?

Female gorillas have slow reproductive rates, and may have only 2-6 offspring over the course of their life span. Male gorillas typically father 10-20 offspring, often with 3-4 different females.

Female gorillas usually reach sexual maturity by 10 years of age, while males do not usually become sexually active until they are 15. Female gorillas approach males to initiate mating, and are only sexually receptive during estrous. They have a 28 day estrous cycle, and after they give birth, they stop ovulating for several years. After an eight-and-a-half month gestation period, a single infant is born.

Mountain gorillas do not have a breeding season, and babies are born throughout the year. If left undisturbed, their population would have the potential to grow at the same rate as our own; however, due to disease, poaching, human encroachment on their habitat, and other destructive factors, gorillas have a high infant mortality rate, and nearly 50 percent of young gorillas die before reaching maturity.

Question 14. How long do baby gorillas stay with their mothers?

Baby gorillas usually nurse until they are three years old, and young gorillas often remain with their mothers for many subsequent years. Newborn gorillas have an average weight of about five pounds, are covered with black hair, and develop at a much faster rate than human babies.

Question 15. At what age do male mountain gorillas develop silver hair on their backs?

Adult male mountain gorillas are known as "silverbacks," because when they reach maturity they begin to develop grayish or silver-colored hair on their backs. In the wild, silverbacks are easily recognizable because of their distinctive color and large size.

Question 16. How much does a full-grown male silverback mountain gorilla weigh?

Adult male mountain gorillas reach typical heights of 5-6 feet, and weights of 450-500 pounds. They are large animals, and can eat up to 50 pounds of vegetation a day.