About Mountain Gorillas
All of the Mountain Gorillas in the world live in the mountains of Africa. Specifically in Rwanda, the Democratic Republic of the Congo, and Uganda.
Gorillas are the largest living primates on Earth. There are three kinds of gorillas: 1) Eastern Lowland Gorillas, which reside in the Democratic Republic of the Congo; 2) Western Lowland Gorillas which live only in West Africa and: 3) Mountain Gorillas, which are only found in Uganda, Rwanda and the Democratic Republic of the Congo.
Gorillas are listed as one of the top 10 most endangered species on Earth. There are approximately 880 Mountain Gorillas alive today. There are none living outside of their native mountain forest home. Gorillas are protected by international law. Capturing or killing gorillas and other endangered species is illegal.
There are no Mountain Gorillas living in captivity and very few Eastern Lowland Gorillas. The gorillas seen in captivity are usually Western lowland gorillas.
Although Mountain Gorillas have been living in the mountains of Africa for a very long time they have only recently been scientifically identified. Captain Robert von Beringe officially identified them in 1902 and as a result the scientific name for the Mountain Gorilla is Gorilla Gorilla Beringei. Andreas von Beringe, grandson, recently visited Mountain Gorillas for the first time in 2002.
There are no territorial boundaries of families but the family’s range from 2 to 15 square miles. When a silverback leaves a group he usually spends 3 years waiting for a female to be attracted to him from another group. Females transfer at least once before mating at 8 years of age.
The females decide who they are going to allow into their family. If a gorilla wants to join another group and the females do not want her in, they will scratch her in the face and keep her out. If a female wants to leave a group to find a male she likes better, but the other females like her very much, they will grab her by the legs and not allow her to leave.
When an adult female is sexually mature she will leave the group to mate with a silverback outside of her group. She chooses who she will mate with, but the females of the group decide if they will allow her into the group. As the head female grooms the dominant silverback, you can see that this is teaching the other gorillas by showing them. The length of time spent grooming a silverback is accomplished by the females in descending order of when they entered the group.
Female gorillas will wean their young at about 3 years of age and can be bred between 61/2 and 9 years of age. Gestation lasts 8 to 9 months. Infants stay within 6 feet of their mothers until 6 months of age. From their birth, infants must use their hands and arms to hang on to the underside of their mother. Their shorter legs and stumpy toes are used only around their mother’s stomach. After 4 months of age they begin to ride on their mother’s back.
Female gorillas weigh approximately 350 pounds and adult male gorillas can weigh approximately 700 pounds. Adult gorillas can be seven feet tall with an arm span of 8 feet.
They eat 58 different types of plant species, including stems, roots, leaves, flowers, thistles, ferns, tree wood and bamboo shoots. Galium vines are favorites as well as berries, fruit and celery. They occasionally will climb trees
Gorillas have much larger teeth in the back of their mouth than humans do so that they can grind foliage, bark and bamboo.
Gorillas are only active part of the day and build nests in different locations each evening. The nests are built of bulky vegetation mostly Lobelia and Senecio branches. Nests can be built on the ground as well as the trees. They start building nests at age three after sharing their mother’s nest. Gorilla groups spend about 40 percent resting, 30 percent eating, and 30 percent traveling.
Gorillas are frequently found eating in unprotected garbage pits, which contain a variety of trash including human toilet waste. This exposes the gorillas to infection and disease that is a major risk to this highly endangered species. The Mountain Gorilla Conservation Fund has been working to construct covered garbage pits. These pits are designed to keep the gorillas from getting to the trash.
A major problem that the veterinarians have had is removing the gorillas from snares that have been set by people. These snares are set to catch animals for humans to eat, but gorillas also get caught in these snares. A hole is dug in the ground and then some branches are put over the top of a rope or wire snare. The animal dies unless he can have the snare removed and wound treated. A wire snare can ruin a gorilla’s eating ability by cutting off its fingers.
Gorillas exhibit behaviors similar to humans. They are curious, they can be bored, they can be bold, they can be annoyed, they can have pleasure, they can be excited, they can be afraid, they can worry, they can show affection, they can be thoughtful or they can be hostile. Gorillas like to study people to see if they are friendly.
Communication between gorillas is accomplished by stomach rumbling which means they are contented, a pig grunt of harsh staccato grunts used when disciplining or complaining. A roar or scream is given when a gorilla is threatened. A loud hoot or roar is given when silverbacks are interacting. This is done by chest beating and thrashing of trees. When gorillas are afraid they send out a powerful odor from their glands. Interactions between social units by silverbacks accounts for over 60 percent of all wounds on gorillas. Gorillas can recover amazingly well.
They live in cohesive social units known as groups. Typical groups consist of 1 dominant silverback, which is a sexually mature male that is 15 years old, that is the group’s definite leader and weighs at least 400 pounds or twice the size of a female. A least one blackback, which is a sexually mature male between 8 –14 years and remains with the group if he does not challenge the dominant silverback. If he does not dominate, blackbacks will leave the group to establish their own group. There are several sexually mature females over 8 years old who are usually bonded to the dominant silverback for life; several immature young adults and juveniles over 3 years; and several infants from birth to 3 years. An adult male is called a silverback. He gets his silver fur when he is between 10-13 years old.
Group size can number over 40 individuals. The long period of association with the parents, elders and siblings offer the gorilla a unique and serene family bonding.
Some gorillas have been identified to live over 40 years.
The Mountain Gorilla Conservation Fund is proud to work with these amazing animals.