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Mountain Gorillas Gorillas_ Chimpanzees_ Bonobo and Orangutans are


									                                      Mountain Gorillas

Gorillas, Chimpanzees, Bonobo and Orangutans are great apes. Humans and great apes
are primates. Humans and gorillas share more than 97% of their genetic material.
Because of the close relationship with humans they are susceptible to human diseases.
Gorilla is the largest living anthropoid. Because there are so few left in the world they are
classified as endangered and protected by international law. CITES (the Convention for
International Trade in Endangered Species of Wild Fauna and Flora) makes the capture
or the killing of wild gorillas and other endangered species illegal.

 There are two species of gorillas, western lowland gorilla (scientific name Gorilla
gorilla ) and eastern lowland gorilla ( scientific name Gorillas beringei). The mountain
gorilla is a subspecies of eastern lowland gorilla. They are found in two forests island :
the Virunga Massif share by Rwanda, Uganda, Democratic Republic of Congo and
Bwindi Impenetrable National Park in Uganda. Mountain gorillas have long fur to help
keep them warm and dry in the cool temperatures and frequent rains of their mountains
home, in contrast with lowland gorillas from warmer climates in western Africa who
have short fur. Gorillas are “sexy flagship species” as they look like human being with
their morphology and that with share the same ancestor.

Most gorillas live in family groups that can be as large over 40 individuals. Larger
groups can have several silverbacks and blackbacks. Mountain gorillas live in a stable
family group lead by a silverback named because of the silver fur that cover his lower
back. This tells the other gorillas that he is sexually mature. A young silverback who has
left his family of birth often lives alone until he can attract females from other groups to
join him
Gorilla age groups are divided as follow:
-Infant         0 to 3,5 years
-Juvenile       3,5 to 6 years
-Sub adult      6 to 8 years
-Adult female from 8 years
-Adult male      8 to 11 years
  black back
-Adult male      over 12 years

Mountain gorillas are polygamous. The dominant silverback is entitled to mate with all
females. When a blackback or a young silverback has grown bigger and stronger , he
will fight the older silverback and take control of the family responsibilities or he will
leave the group to attract other females and begin his own family. The silverback is the
leader of his family group. His job is to protect his family members and area surrounding
them. They may be more than one silverback in a group. The older more experienced is
in charge. A silverback is gentle with other family members. Young gorillas are often
seen sitting by him or climbing on him. Gorillas are protective of their family but will
attack anyone who tries to harm them. A silverback can weight between180-230 Kg and
height 1,70 –1,80 m maximum
A gorilla group could have many adult females. The older females are leaders to younger
ones. Once mature a female will leave the group of her birth to mate with a silverback
outside of her family. Some females will allow younger silverback to mate with them
without the dominant silverback knowledge. Mating happens only when a female is in
heat. Like people , she is pregnant for 9 months. She can have one baby about every four
to five years. An adult female can have 4 to 5 infants in her life. A newborn can weight
between 1,5 to 2kg. Twins have been recorded but still rare. On may 19th 2004, in Susa
group , one of the habituated gorilla group of the National park in Rwanda twins were
born. So far they are growing well and in good health. It is unusual to have twins who
could survive for so long. This is the first case of mountain gorilla twins to live for such a
long period of time.

They wake up at sunrise and eat plants through the morning. Gorilla have a slow peaceful
daily routine of eating and sleeping. During their resting time they spend much time
gently cleaning each other’s fur by picking out dirt, plant parts this is called grooming..
The silverback leads the group to new feeding areas.
Adult gorillas make nests at night to sleep in, as well as day nest for midday naps. They
make soft ground “pillows” by folding down flexible leafy stems. Each gorilla sleep in a
separate nest except the young gorillas (less than 4 years old) who share their mother’s

An infant gorilla is dependent upon its mother during its three years. Its stays with his
mother’s arms for the first few months. After about six months the baby rides on the
mother’s back. By the age of four the young gorilla is independent enough and is through

Gorilla have been known to live for about 45 years

Each gorilla has a different pattern of wrinkle on its nose. This noseprint helps park staff
and scientists to tell one gorilla apart from another which is a way to identify individual.

Gorillas have been seen eating more than 100 different kinds of plants and plant parts,
some of their favorite foods are bamboo, nettles, celery and gallium. Gorillas eat a lot,
but rarely drink water because they get most of their liquids they need from plant they
eat. Occasionally gorillas have been seen eating insects. An adult mountain gorilla can
eat up to 30 Kg of vegetation a day.

Gorillas communicate with other gorillas by making a variety of different
sounds/vocalizations, such like the soft throat-clearing “mhammm” tells the group that all
is well, pig-like grunt is a call for discipline because of unwanted behavior. The other
way a gorilla can communicates with others is by beating his chest.

Common causes of death in gorillas are snare wounds and poaching, respiratory
infections. Poaching remains a threat for the survival of mountain gorillas.
The last census completed at the end of 2003 showed a population of 380 individuals in
the Virunga massif (Rwanda, Uganda, Democratic Republic of Congo). The evolution of
the gorilla population is:

*1971-73             274
*1976-78             268
*1981                254
*1986                293
*1989                324
*2003                380

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