The mountain gorilla (Gorilla beringei beringei) is one of the two subspecies of the eastern gorilla. It is listed as critically endangered by the International Union for the Conservation of Nature (IUCN). There are two populations; one is found in the Virunga volcanic mountains; within three National Parks: Mgahinga, in south-west Uganda, in north-west Rwanda and Virunga in the eastern Democratic Republic of Congo (DRC). The other is found in Uganda’s Bwindi Impenetrable Forest National Park.
The fur of the mountain gorilla is often thicker and longer than that of other gorilla species which enables them to live in colder temperatures. Adult males are called silverbacks because of a saddle of gray or silver-colored hair which develops on their backs with age. The hair on their backs is shorter than on most other body parts and their arm hair long. Gorillas can be identified by nose prints unique to each individual. Males have a weight of 195 kg (430 lb) upright standing with a height of 150 cm and usually weigh twice as much as the females. Adult males have more pronounced bony crests on the top and back of their skulls, giving their heads a more conical shape.
The mountain gorilla is most active between 6:00 am and 6:00 pm. Many of these hours are spent eating as large quantities of food are needed to sustain its massive bulk. It forages in early morning, rests during the late morning and around midday and in the afternoon it forages again before resting at night. Each gorilla builds a nest from surrounding vegetation to sleep in and constructing a new one every evening. Only infants sleep in the same nest as their mothers. Gorillas leave their sleeping sites when the sun rises at around 6 am, except when it is cold and overcast; then they often stay longer in their nests. Like all great apes other than humans, its arms are longer than its legs. It moves by knuckle-walking (like the common chimpanzee), supporting its weight on the backs of its curved fingers rather than its palms.
Habitat and ecology
The mountain gorilla inhabits the Albertine Rift montane cloud forests and of the Virunga volcanoes. The vegetation is very dense at the bottom of the mountains, becoming sparser at higher elevations, and the forests where the mountain gorilla lives are often cloudy, misty and cold. The mountain gorilla spends most of its time in the Hagenia forests, where gallium vines are found year-round. All parts of this vine are consumed; leaves, stems, flowers, and berries. It travels to the bamboo forests during the few months of the year when fresh shoots are available and it climbs into subalpine regions to eat the soft centers of giant senecio trees.
The mountain gorilla is primarily herbivore; the majority of its diet is composed of the leaves, shoots and stems. It also feeds on roots (3.3%), flowers (2.3%), and fruit (1.7%), as well as small invertebrates (0.1%). Adult males can eat up to 34 kilograms (75 lb) of vegetation a day, while a female can eat as much as 18 kilograms (40 lb).
The mountain gorilla is highly social and lives in relatively stable, cohesive groups held together by long-term bonds between adult males and females. The dominant silverback generally determines the movements of the group, leading it to appropriate feeding sites throughout the year. He also mediates conflicts within the group and protects it from external threats. When the group is attacked by humans, leopards, or other gorillas, the silverback will protect them even at the cost of his own life. He is the center of attention during rest sessions and young gorillas frequently stay close to him and include him in their games. If a mother dies or leaves the group, the silverback is usually the one who looks after her abandoned offspring, even allowing them to sleep in his nest. When the silverback dies or is killed by disease, accident, or poachers, the family group may be disrupted. Unless there is an accepted male descendant capable of taking over his position, the group will either split up or adopt an unrelated male. When a new silverback joins the family group, he may kill all of the infants of the dead silverback.
A typical group contains: one dominant silverback, who is the group’s undisputed leader; another subordinate silverback (usually a younger brother, half-brother, or even an adult son of the dominant silverback), one or two black backs who act as sentries; three to four sexually mature females who are ordinarily bonded to the dominant silverback for life and from three to six juveniles and infants.
Males leave when they are about 11 years old and often the separation process is slow; they spend more and more time on the edge of the group until they leave altogether. They may travel alone or with an all-male group for 2–5 years before they can attract females to join them and form a new group. Females typically emigrate when they are about 8 years old, either transferring directly to an established group or beginning a new one with a lone male. Females often transfer to a new group several times before they settle down with a certain silverback male.
The midday rest period is an important time for establishing and reinforcing relationships within the group. Mutual grooming reinforces social bonds and helps keep hair free from dirt and parasites. Young gorillas play often and this helps them learn how to communicate and behave within the group. Activities include wrestling, chasing, and somersaults. The silverback and his females tolerate and even participate if encouraged.
For reasons unknown, mountain gorillas that have been studied appear to be naturally afraid of certain reptiles and insects. They are also afraid of water and will cross streams only if they can do so without getting wet, such as crossing over fallen logs.
Sounds classified as grunts and barks are heard most frequently while traveling and indicate the whereabouts of individual group members. They may also be used during social interactions when discipline is required. Screams and roars are used for alarm or warning and are produced most often by silverbacks.
Although strong and powerful, the mountain gorillas are generally gentle and very shy. Severe aggression is rare in stable groups but when two mountain gorilla groups meet, the two silverbacks can sometimes engage in a fight to death, using their canines to cause deep gaping injuries. For this reason, conflicts are most often resolved by displays and other threat behaviors that are intended to intimidate without becoming physical.
Conservation efforts have led to an increase in overall population of the mountain gorilla (Gorilla beringei beringei) in the Virungas and at Bwindi. In both Bwindi and the Virungas, groups of gorillas that were habituated for research and ecotourism have higher growth rates than unhabituated gorillas. Habituation means that through repeated, neutral contact with humans, gorillas exhibit normal behavior when people are in proximity. Habituated gorillas are more closely guarded by field staff and they receive veterinary treatment for snares, respiratory disease and other life-threatening conditions. Nonetheless, researchers recommended that some gorillas remain unhabituated as a bet-hedging strategy against the risk of human pathogens being transmitted throughout the population. Despite their recent population growth, the mountain gorilla remains threatened. As of 2008, mountain gorillas were listed as Critically Endangered on the IUCN Red List and are dependent on conservation efforts to survive.
This is one of the most severe threats to gorilla populations. The forests where mountain gorillas live are surrounded by rapidly increasing human settlement which leads to the reduction of the genetic diversity for each group. Through shifting (slash-and-burn) agriculture, pastoral expansion and logging, villages in forest zones cause fragmentation and degradation of habitat. The resulting deforestation confines the gorillas to isolated deserts. The impact of habitat loss extends beyond the reduction of suitable living space for gorillas.
Mountain gorillas are not usually hunted for bush meat but they are frequently killed by traps and snares intended for other animals. They have also been killed for their heads, hands, and feet, which are sold to collectors. Infants are sold to zoos, researchers, and people who want them as pets. The abduction of infants generally involves the loss of at least one adult, as members of a group will fight to the death to protect their young
Despite the protection garnered from being located in national parks, the mountain gorilla is also at risk from people of a more well-meaning nature. Groups subjected to regular visits from tourists and locals are at a continued risk of disease cross-transmission, this is in spite of attempts to enforce a rule that humans and gorillas be separated by a distance of 7 metres at all times to prevent this. With a similar genetic makeup to humans and an immune system that has not evolved to cope with human disease, this poses a serious conservation threat.
Difference between Gorillas and Chimpanzees
- Male chimps are usually less than 70 kg and are around 120 cm tall. Male gorillas weigh around 150 kg and are around 180 cm tall. Females of both species weigh less than males and stand shorter.
- Gorillas have larger head crests, larger jaw muscles, larger limbs and thicker bones. Their feet and hands are less flexible. Chimps have more slender hands and feet and their thumbs are proportionately larger.
- Chimps have proportionately larger brains and are slightly more intelligent on average.
- Gorillas have higher sexual dimorphism than chimps.
- Chimps can make simple spears, chew leaves to use as sponges, throw stones to deter baboons, use a rock and anvil to crack nuts and use a stick to fish termites. They have also been seen using sticks as weapons against others. Gorillas have been seen using sticks to check the depth of water, make tree nests and they can also fish for termites.
- Gorillas have black skin and dark brown/black hair. Alpha males can have silver backs. Different subspecies have different hair thickness. Chimps have peach or black skin and black hair.
- Gorillas are mostly herbivorous but some do eat termites. They also eat fruit but in smaller quantities. Due to their larger colon and appendix, they can have a high fibre diet and they eat leaves, nettles, celery, some roots and stems. Eating meat can upset their gut bacteria composition and this can cause heart diseases. Gorillas can spend 8 hours a day eating.
- Chimps have many males and females who have multiple breeding partners. There is a strict hierarchy and chimps become higher by fighting or popularity. Females leave the group to avoid inbreeding. Chimps can plan and team up to remove a leader. Chimps also wage war on neighboring clans and will steal their trees, territory and members. Some of the stolen members could end up as food.
- Chimps and gorillas both live in trees but gorillas climb less due to their habitat and weight. They both nest in trees but sometimes on the ground if they are too heavy.
- As signs of aggression, chimps kick trees and scream. They show all their teeth. Gorillas beat their chests and charge.
FREQUENTLY ASKED QUESTIONS
What are mountain gorillas?
Gorillas are the largest living primates and they make their homes in central and east Africa. They function in well-developed social structure and often exhibit behavior and emotions similar to the human experience including laughter and sadness.
How are mountain gorillas related to humans?
Gorillas share 98%of their DNA with humans. They are our closet cousins after chimpanzees and bonobos.
Where can you find mountain gorillas in Uganda and Rwanda?
In Uganda Mountain Gorillas are found in Bwindi Impenetrable National Park and Mgahinga Gorilla National Park. In these areas tracking takes place at 5 locations Buhoma, Ruhija, Rushaga, Nkuringo in Bwindi Impenetrable National Park and Ntebeko in Mgahinga Gorilla National Park, however the permit number are limited because only 8 people are allowed to visit a gorilla family per day for only one hour. In Rwanda gorillas can be found in Virunga National Park.
What is the gestation period of Gorilla Mountains?
Females have a gestation period of 8.5 months and nurture their young for several years. Generally, females give birth to one baby every four to six years. This slow population makes it harder for gorillas to recover from any population decline.
Where do we purchase Gorilla permits in Uganda?
All gorilla permits Ssemambo Alex Tours & Travel issues to clients are purchased from Uganda Wildlife Authority as opposed to the black market. It is a Government conservation institution entrusted with managing Uganda’s national parks and game reserves.
How far can I stay from the gorillas?
Gorillas are vulnerable to transmission of diseases from humans. To this effect, tourists are expected to keep a 7 meter radius from gorillas when tracking, although in most cases gorillas tend to abuse this rule by coming closer to you as you stand quietly observing or photographing them. However, you are always encouraged to maintain this distance by staying away from the gorillas and you are not allowed to touch them though it would be easy to do especially as they come closer to you.
How many days should I book for my gorilla tracking tour?
You will need to set aside at least three days to see the gorillas in Uganda. Allow one day for travel to your accommodation, one day for the gorilla tracking and a third day for travel back or onwards wherever you opt for. You will need to be up very early on the day of the gorilla tracking and so you will need to arrive at your lodge by 6 or 7 PM on the day before you track.
Where and when is it possible to track Mountain Gorillas?
Mountain gorilla tracking is only available in Uganda and Rwanda. Gorilla trekking can be done throughout the year though best experiences happen in the dry season between June, September and December to February. In Uganda, mountain gorilla tracking is more paramount in Bwindi Forest National Park with about 12 gorilla families that can be tracked. Mgahinga gorilla national park is Uganda’s second gorilla tracking destination with one gorilla family of Nyakagezi. Rwanda has got one mountain gorilla-tacking destination in Volcanoes national park, which is also part of the Virunga Conservation Area.
How do gorillas find their food?
In areas near human communities, gorillas are attracted by crops, which they can eat. They hardly drink water directly from the source because they get the liquid from the vegetation they eat.
How does gorilla-tracking compare in Rwanda and Uganda?
The experience of tracking mountain gorillas in Uganda and Rwanda is not so different. Most tour companies like Ssemambo Alex Tours & Travel organize Uganda-Rwanda gorilla trips to have the experience of gorilla tracking in both countries. However, there are very few differences and the main one is the difference in the price of a gorilla permit. A single gorilla permit in Rwanda costs 1500USD for all travelers compared to Uganda’s 700USD for foreign nonresidents and 250,000shs for East Africa residents. Both countries have the same policies regarding trekking mountain gorillas including grouping trackers in groups of eight to track a single gorilla family, they both allocate one hour of tracking mountain gorilla and they both have the same rules and regulations while tracking gorillas. Another difference is in the geography of the parks whereby Bwindi in Uganda is has thick vegetation and with no clear trails while volcanoes national park in Rwanda is less thick and has got some clear tracking trails.
How difficult is gorilla trekking?
First of all; you must be willing to take on a hike in rough terrain and in any weather to see the gorillas in the wild. Besides, the parks’ management also works tirelessly to help you trek the gorillas successfully regardless of all your setbacks. This is done in many ways including assigning you to park guides and rangers to make it as easy as possible to track and photograph the gorillas and also ensure your security while in the wild.
How much time can I spend with the mountain gorillas?
In all gorilla destinations, tracking permits allow travelers a maximum of an hour with a habituated gorilla group. However, due to a few inconveniences like if you had a long trek to reach your gorilla family; your guide may allow you a few more minutes. Mountain gorillas are wild and they prefer being in their own company doing their wild activities like eating, playing and mating rather than being surrounded by humans for a long time. This is why the time is restricted to one hour.
Are the mountain gorillas dangerous?
Although mountain gorillas are wild animals just like the rest in the jungle, they are not potentially dangerous. They are not aggressive or prone to be angered by tourists and they always seem to ignore them completely even when they are in their midst. However, you should not try to get in-between a mother and a baby or tease them, don’t use a flashlight, make distracting noises or move quickly as all these actions are deemed provocative to these endangered species.
Which is the best country to go gorilla trekking, Uganda or Rwanda?
The mountain gorilla trekking in Uganda and Rwanda inhabit similar rugged terrain and have similar habits. The regulations and quality of local gorilla guides and trackers is similar in Rwanda and Uganda but there are as many factors to consider in picking your location within one of these countries. The gorilla families are not in a zoo but roaming free in a very large area of very dense forest and so many factors such as the length of your trek or how open the area you end up encountering the gorillas in, cannot be planned for. Therefore gorilla trekking in Uganda or Rwanda, all is interesting depending on your choice.
What is the trekking time?
In regards to trekking time, it starts in the early morning after a simple briefing by the park rangers/guides. Once the trekking begins, there is no specific time to spend in the jungle but vary depending on the movements of gorillas and where they slept the previous night. This means that fortunate trekkers can meet the gorillas in a short time as 30 minutes or else as late as 6 hours if not the whole day. However, whether it takes short of a long time, trekkers are 99.9% sure of meeting the gorillas.
What is included in the permit?
The permit is an inclusion of the park entrance fee, the money for the park rangers who guide during the trekking and other services in the national park except for the accommodation.
Which gorillas do you see in zoos?
All the gorillas in zoos are lowland gorillas. Most of them are actually western lowland gorillas.
How different is Gorilla trekking from Gorilla habituation?
There are so many differences between gorilla trekking and gorilla habituation. Gorilla trekking costs 700USD and you get to spend only one hour with the mountain gorillas while gorilla habituation costs 1500USD allowing you to spend four hours with the mountain gorillas. Habituation only takes places in regions that have mountain gorillas under habituation that is; in Rushaga and Nkuringo where we have Gorilla groups of Bikingi and Bushaho are under habituation.
Can I do gorilla habituation experience in any region of Bwindi?
Gorilla habituation experience is currently possible in Rushaga and Nkuringo located in Bwindi Impenetrable Forest National Park. It is thus not possible in Buhoma or Ruhija side of the forest. This is because currently, it is only in the two sectors of Rushaga and Nkuringo that we have two mountain gorilla families being habituated as compared to other regions.
When does gorilla habituation experience start?
Unlike gorilla trekking which starts at 8:30 am, mountain gorilla habituation starts at 7:30am and briefing is done much earlier.
What is included in the gorilla habituation experience permit?
This includes rangers, researchers and spending four hours with mountain gorillas under habituation. It also includes park entrance fees for Bwindi Impenetrable National Park.
How many gorilla species do we have on planet earth?
There are 4 subspecies of gorillas on our beautiful planet: the mountain gorilla, eastern lowland gorilla, western lowland gorilla, and cross river gorilla.
What is a group of gorillas called?
A group of gorillas is called a band or a troop. Up to this day, there is nowhere in the world you can see wild mountain gorillas without visiting the bands’ true natural habitat. Visit Africa and you can make your own decision on whether it’s a troop or a band.
What else can I do in Uganda besides Gorillas?
Uganda has got a lot to offer to her visitors including wonderful cultural tours, game viewing and game drives in her large wildlife parks and spectacular birding experience. When it comes to birds, Uganda may be the best safari country in Africa for a large variety of bird species and great birding safari habitats. While on your Uganda mountain gorilla safari or birding safari trip, you are likely to see many other primate species including golden monkeys and chimpanzees.
What do I need for Gorilla trekking?
We advise a pair of gloves, clothing that protects your arms and legs from thorns and nettles, long socks to enable you tack in your trousers, a hat, hiking boots, garden gloves, sun glasses, cameras and extra batteries, rain jacket, some energy giving foods and insect repellents.
Gorilla permits bookings
Ssemambo Alex Tours & Travel do bookings for gorilla trekking permits, chimp permits and golden monkey permits in Uganda and Rwanda. Contact us and we will check for your permit availability and advise you accordingly. We recommend that you book your gorilla permits at least 6 months in advance to avoid disappointments.