Mountain Gorillas

Mountain Gorillas

Mountain Gorillas

Mountain Gorillas are one of the most sought for species when travelers visit East and Central Africa as they have been termed endangered species with 98% DNA similar to humans. A mountain gorilla is one of the two subspecies of the Eastern gorilla and is listed as an endangered species by the International Union for Conservation of Nature(IUCN) as of 2018. There are two populations of the mountain gorillas with one being found in the Virunga ranges within national parks like Mgahinga National Park in south-western Uganda, Volcanoes National Park in north-western Rwanda and Virunga national park in the east of the Democratic Republic of the Congo: and the other population in Bwindi Impenetrable National Park in Uganda. As of June 2018, there were over 1,000 mountain gorillas recorded, with Bwindi Impenetrable National Park inhabiting more than half of the total.

The vegetation in the above places is very dense at the slopes and they are often cloudy, misty and cold.

Physical Description of the mountain gorillas

The fur of the mountain gorilla is often thicker and longer than the fur of the other gorilla species say the lowland gorillas, which fur helps them live in colder temperatures successfully. Gorillas can be identified by their nose prints which are unique to each individual.

Male mountain gorillas have a mean weight of 195kg and a height of 150cm when standing upright, which is usually twice as much as the female gorillas which have a mean weight of 100kg and height 130cm. Adult males have more pronounced bony crests on the top and back of their skulls giving their heads a more conical shape. Adult females also have these crests but are less pronounced. Like all other gorilla species, mountain gorillas have dark brown eyes framed by a black ring around the iris. 

Adult males are called silverbacks because of a saddle of gray or silver-colored hair that grows on their backs with age. The hair on a silverback’s back is shorter than on most other body parts.

The mountain gorilla is majorly terrestrial and quadrupedal. They can, however, climb fruiting trees if the branches can hold their weights, or simply erect themselves higher to reach the fruits. Mountain gorillas move by knuckle-walking, supporting their weight on the backs of their curved fingers rather than the palms.

Mountain gorillas are most active between 6:00 am and 6:00 pm and many of these hours are spent eating. They are primarily herbivores with their food being composed of leaves, shoots, and stems, plus roots, flowers, and fruit. They go in search for food early in the morning then rests in the late morning and in the early afternoon say at around midday, and searches for food again in the afternoon before resting at night. Mountain gorillas eat large quantities of food to sustain their huge selves. Adult male mountain gorillas can eat up to 34kgs of vegetation a day while a female up to 18kgs a day. Mountain gorillas each builds its own nest from surrounding vegetation for sleeping every single evening, they never sleep in the same nest as they are never in the same place. Infants sleep in the same nest as their mothers. The gorillas rise with the sun except on those days that are very cold and overcast when they stay in longer in their sleeping places.

The behavior of mountain gorillas

Mountain gorillas are highly social primates that live in relatively stable and cohesive groups. Silverbacks are the heads/leaders of a family or group. Most gorilla groups are composed of one silverback and a number of females. Some of the groups, however, have more than one male gorilla. Male gorillas leave their natal group usually at the age of eleven in a slow process where they often times spend more time at the edge of the group gradually going further up until they leave altogether. They may live alone or be with a few other male gorillas for a period of not more than 5 years until they eventually attract the females. The females, however, leave their natal groups at an age of 8 joining an already established group or begin one with a lone male. 

The dominant silverback determines the movements of the group. It leads them to the right feeding areas throughout the year, mediates conflicts in the group and protects it from external attacks from say humans, or other gorillas with his own life. He is oftentimes the center of attention during the rest periods. When a mother dies or leaves the group, the silverback is usually the one that looks after the abandoned offspring and can even share his nest with it. Upon his death, a family group can be disrupted and if there is no accepted male descendant, the group can either split up or adopt an unrelated male. If a new silverback takes over a family group however, he may decide to kill all the infants of the dead silverback.

The reproductive rate of mountain gorillas is quite slow as the females usually give birth after a gestation period of 8.5 months birthing one baby gorilla. Twins are a rare scenario among mountain gorillas though some are noted. 

Mountain gorillas are generally gentle and shy primates. They rarely become severely aggressive say when two family groups meet, the two silverbacks can sometimes fight to the death using their canines to cause deep injuries. Conflicts can be avoided with a display of threat behaviors that are intended to intimidate without actually being physical. The charge display is unique to gorillas but generally includes the following;

  • Progressively quickening hooting
  • Symbolic feeding
  • Rising bipedally
  • Throwing vegetation
  • Chest-thumping with cupped hands
  • One leg kick
  • Sideways running when four-legged
  • Slapping and tearing vegetation
  • Thumping the ground with palms

There are over twenty distinct vocalizations recognized which are used by family groups to communicate. Grants and barks are heard most often when in the forest and they indicate the location of different groups. Screams and roars signal alarm or warning usually produced by a silverback; deep rumbling belches suggest contentment.

Mountain gorillas have been studied to naturally be afraid of certain reptiles and insects. The infants generally stay away from chameleons and caterpillars. It is also important to note that these gorillas are near humans and they share about 98% DNA.

Mountain gorillas are threatened by diseases which they can easily acquire from humans, habitat loss due to the rapidly expanding human settlements and fragmentation, poaching due to traps that are usually set up for other animals and abduction of the infants for sale as pets, and war and unrests which exposes them to the displaced as meat and also landmines that are placed along the forests.

Mountain Gorillas
Mountain Gorillas

Some of the mountain gorillas are habituated that they can allow human contact. Habituated gorillas are more closely guarded by rangers and they receive treatment for snares, respiratory diseases and other infections that they might have acquired. This is made possible to provide to the mountain gorillas through the funds from among others the revenue collected when travelers purchase gorilla trekking permits and gorilla habituation passes. Take time and plan to visit these endangered species and you would not only have a wonderful time with them but also contribute to their conservation efforts.

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