What are the enemies of the mountain gorillas

Eastern gorilla in the species lexicon

Gorillas are the largest great apes after humans. In the genus of gorillas, a distinction is made between the eastern and western gorillas. The fur of the somewhat larger and stockier eastern gorillas is colored black. In addition, they lack the red-brown "cap" on their heads that is typical of Western gorillas. Mountain gorillas, one of two subspecies of the Eastern gorillas, can be recognized by their particularly long, thick and shaggy fur, especially on the arms of the males. Adult gorilla males are also called silverback because of their gray back hair. Eastern gorillas live in groups of one or more silverbacks, several females and the offspring. They have the smallest range among the African great apes. The countries in which they are distributed have been plagued by political unrest and wars, from which the gorillas also suffer, since the early 1990s. Although gorillas have traditionally been hunted very rarely for human consumption and, like all other great apes, are protected, thousands of Eastern lowland gorillas, the other subspecies of the Eastern gorillas, have been killed by bushmeat poaching in recent decades. In addition, Eastern gorillas have already lost 87 percent of their historical habitat. The main reasons for this are the extensive conversion into agricultural land and the extraction of natural raw materials, especially mineral resources such as diamonds, gold and coltan. The income thus generated is invested in weapons and warfare by the various military units and rebel groups. Overall, more than three quarters of the total population of the Eastern lowland gorillas were wiped out between 1995 and 2015. It looks different with the mountain gorillas. They are the only great apes whose numbers have increased slightly in recent years, but at least.


Eastern gorilla in profile

SubspeciesEastern lowland gorilla or gray gorilla (G. b. Graueri), mountain gorilla (G. b. Beringei)
habitatEastern lowland gorillas: tropical lowland rainforests, secondary forests, mountain forests, bamboo forests, swamp forests and peat bogs at altitudes of 600 to 2,900 meters; Mountain gorillas: mountain forests, bamboo forests, mixed forests and grasslands at altitudes of 1,850 to 3,800 meters
Geographical distributionEastern lowland gorillas: eastern part of the Democratic Republic of the Congo; Mountain gorillas: Eastern part of the Democratic Republic of the Congo, northwest Rwanda and southwest Uganda in the five protected areas of Bwindi National Park, Mgahinga Gorilla National Park, Sarambwe Reserve, Virunga National Park and Volcano National Park
Endangerment statusIUCN: According to the Red List of the International Union for Conservation of Nature IUCN, Eastern gorillas are "critically endangered"
Stock sizeThe total population today is less than 5,000 Eastern Gorillas. The latest counts showed around 1,000 mountain gorillas in 2018 and around 3,800 eastern lowland gorillas in 2015.

Where are eastern gorillas classified in the zoological classification?

Of orders, families and species

The Eastern Gorilla (Gorilla beringei) belongs to the family of great apes and to the order of primates. Together with the gibbons and their relatives, the great apes form the group of Old World monkeys. The Old and New World monkeys are the two relatives of the apes, which in turn, together with the goblin tarsier, form the suborder of the dry-nosed monkeys. The dry-nosed monkeys belong next to the wet-nosed monkeys to the mammalian order of primates.

The great ape family is now divided into four genera with seven species: Eastern gorilla, Western gorilla, bonobo, common chimpanzee, Sumatran orangutan, Bornean orangutan and human. The two gorilla species belong to the same genus and are most closely related to each other among the great apes. However, the eastern gorillas were initially regarded as a subspecies of the western gorillas and have only been recognized as a separate species since 2001.

There are two subspecies of the Eastern gorillas: Eastern lowland gorillas (G. b. Graueri) and mountain gorillas (G. b. beringei), which have been developing separately for an estimated 400,000 years. Eastern lowland gorillas are sometimes also called gray gorillas, a name in honor of the African explorer Rudolf Grauer. As research progressed, a few years ago the discussion arose whether the mountain gorilla population of the Bwindi mountain gorillas might not even represent a third independent subspecies of the Eastern gorillas. So far, however, they are still considered a subspecies.

What do eastern gorillas look like?

Features, properties and special features

Gorillas are the largest great apes after humans. The eastern gorillas, on the other hand, are slightly larger than the western gorillas. The gorilla males are about twice as massive as the females. The head-torso length of Eastern gorilla males is up to 120 centimeters. Standing, males reach a size of up to 1.96 meters and females up to 1.50 meters. The arms stretched out to the side have a span of 2 to 2.75 meters. Males weigh around 120 to 209 kilograms and females 60 to 98 kilograms.

Gorillas have a large, oval head, a strong body with a broad chest and long limbs. As with all great apes except humans, the arms of the gorillas are longer than the legs. The fur of the eastern gorillas is black. The face, ears, palms and soles of the feet are hairless and also black. The face is flat, only the jaw part protrudes forward. There are so-called bulges above the eyes - a thickening of the frontal bone. The ears are small but clearly visible, and the nostrils are noticeably large. Like most monkeys, the big toes of the feet can be opposed like our thumbs. For this reason, the feet function as so-called gripping feet.

During puberty, males develop a number of characteristic secondary sexual characteristics that, at first glance, distinguish them from females. The skull of the male gorillas has a broad bony crest on top of the head. This pronounced bone ridge serves as a starting point for the strong jaw muscles. This gives the males a huge bump on their head. With the mouth open, it is possible to see the long, pointed canine teeth of the males. The chest of the males is particularly broad and more and more hairless with age. Because of the gray hair on the back, adult males are also called silverback.

Like other African great apes, gorillas typically move on the ground on four feet in what is known as an ankle gait. They step on the soles of the feet at the back, while the fingers in front are curved into an open fist and only the middle phalanges and the ankles touch the ground. For a while, gorillas can also stand upright and are able to cover short distances on two legs. Eastern gorillas do not climb as well as western gorillas due to their larger body mass.

Outwardly, the two subspecies of the Eastern gorilla only differ in terms of a few features. Eastern lowland gorillas are on average slightly larger than mountain gorillas, although in some cases these are among the largest gorillas at all. Mountain gorillas have a slightly larger head, a broad face and a more pronounced chin area. Eastern lowland gorillas, on the other hand, have a long, thin face. The nostrils of the eastern lowland gorillas are rounded and of the mountain gorillas they are more angular. In addition, the fur of the mountain gorillas is particularly long, dense and shaggy, especially on the arms of the males. Eastern lowland gorillas have slightly longer arms than mountain gorillas in relation to their height. In the mountain gorillas there are also some subtle differences between the two spatially separated populations. The Bwindi mountain gorillas are slightly smaller and narrower than the Virunga mountain gorillas. They also have slightly shorter hair. In return, they have slightly longer arms, legs, hands and feet than their subspecies in the region of the Virunga volcanoes in relation to their body size.

The two gorilla species are also very similar. Eastern gorillas are slightly larger and stockier than western gorillas. You have slightly shorter arms in relation to your height. Their fur is black in color while that of the western gorillas is brown. Eastern gorillas also lack the red-brown “cap” on their heads. The gray fur of the silverback is limited to the back of Eastern gorillas and extends to the thighs of Western gorillas.

How do eastern gorillas live?

The social organization, activity and communication

Knowledge of the Bwindi mountain gorillas and eastern lowland gorillas is even more limited than that of the Virunga mountain gorillas and western gorillas. Gorillas typically live in fixed polygynous, so-called harem groups consisting of a dominant silverback and several females with their offspring. On average, the groups of Eastern gorillas include ten adults and sub-adult animals plus the gorilla children. In individual cases, the groups can also consist of up to 65 gorillas. In contrast to the typical so-called “unimal” groups of the western gorillas, around 40 percent of the groups of the eastern gorillas are led by several silverbacks instead of one. So-called "multimal" groups with up to nine silverbacks have already been observed in them. Multi-male gorilla groups are most common in Bwindi mountain gorillas and least common in Eastern lowland gorillas. Genetic studies show that the males are mostly, but not always, related to one another. There is then a ranking among the males with an alpha male at the top. If a group with only one silverback dies, the group dissolves. If the highest-ranking male is killed in a group with several silverbacks, a lower-ranking silverback usually takes the lead. The silverback always has priority when eating. There is also a ranking among the females, but this is only weak.

The groups of gorillas are by and large stable. However, there are group changes from time to time. When changing groups, a distinction is made between primary and secondary changes. Primary group changes occur during puberty, when young gorillas leave their birth group. Secondary group changes affect adult females only. They occasionally change groups, for example if they are poached by males without a group, if their group has split up or if they prefer a group with more males and thus a lower risk of infanticide (see below). The group changes typically take place when groups meet. When females with dependent children join a new group, they are often killed by the new group's silverback other than the father. Due to the infanticide, the new females are ready to mate again as quickly as possible. Overall, infanticide occurs significantly less often in groups with several males.

When young Eastern male gorillas leave their birth group, they usually move around alone at first until they have managed to poach a few females who can join them and thus set up their own groups. Sometimes several young males get together and form a group together. In rarer cases, when they get on particularly well with the dominant silverback, young males stay in their birth group so that they can take over in later years. Which path a young male chooses depends on many different factors, such as the structure of the birth group or relationships. When leaving the group of young eastern lowland gorilla males, it can also happen that a few females follow the males. The young females of the Virunga mountain gorillas mostly leave their birth groups individually, but those of the eastern lowland gorillas often together. In rare cases it has also been observed that young females remain in their birth group and reproduce there with lower-ranking males.

In the groups, close bonds develop between males and females, which are ultimately important for both parties in order to ensure their own reproductive success. Relationships are strengthened through regular grooming and games. However, there are occasional aggressive interactions between the two sexes. The females in a group are often unrelated and not particularly related to one another. Most quarrels occur between adult females. However, they usually just scream at each other and don't attack each other. A silverback often intervenes to arbitrate. Like all great apes, females develop intimate mother-child bonds and form solid units with their offspring over the years. You spend a lot of time grooming. In groups with several adult males, they interact little with one another. Since they are ultimately competitors for females, there can also be extremely aggressive arguments between them. These can end up with the males seriously injuring themselves. On the other hand, they cooperate in preventing the females in their group from changing groups. Lower-ranking males usually stay on the fringes of the group. It's much more relaxed in groups that only consist of young males. For example, proximity, games and grooming can be observed more frequently with them. Nevertheless, there are also disputes, but they are usually harmless.

The characteristic breast drumming is part of the impressive behavior of rival silverbacks. This is also used in other contexts, for example in play, by females and young animals, but gets an impressive response from the males due to the laterally bulging larynx ventricles that are only present in them. If impressing is not enough to clarify the fronts, the males will attack each other. At first they hunt each other and typically strike symbolically against trees and bushes. It is only in the last step that violent attacks actually occur.

The groups wander around in search of food. The distances covered differ in the different altitudes of the distribution areas. The availability of fruits decreases with increasing altitude and with it the length of the daily hikes. Eastern lowland gorillas travel around 1.5 kilometers per day, while Virunga mountain gorillas often move less than 600 meters per day. The roaming areas of the Eastern lowland gorillas and Bwindi mountain gorillas cover an area of ​​around 16 to 28 square kilometers, those of the Virunga mountain gorillas six to eleven, but sometimes up to 34 square kilometers. The grazing areas of several groups can largely overlap. In the case of Eastern gorillas, food is abundant and widely available and so there is little food competition between the groups. Even so, neighboring groups seem to avoid encounters.

Eastern gorillas are diurnal and mostly stay on the ground, but also in trees. Bwindi mountain gorillas spend more time in the trees than Virunga mountain gorillas and eastern lowland gorillas. Eastern gorillas are active around 12 hours a day and spend most of their time searching for and eating food, interrupted by several periods of rest. To sleep, they build a new nest every evening. Compared to western gorillas, they build ground nests more often and tree nests less often. Virunga mountain gorillas almost exclusively sleep in ground nests and eastern lowland gorillas at lower altitudes around half in ground and tree nests. In general, younger gorillas are more likely to build their nests in trees than adult gorillas.

The interspecific food competitors of the eastern gorillas include chimpanzees, with whom they share large parts of their range and with whom their food spectrum overlaps. But the diet of the two species differs enough that they can coexist. Encounters between eastern gorillas and chimpanzees are usually peaceful. The natural enemies of the gorillas are the leopards. However, these no longer occur in the range of the mountain gorillas.

What is known about the reproduction of Eastern Gorillas?

From mating through the development of the young to adulthood

In the case of Eastern gorillas, the females become sexually mature at around six to seven years of age. However, they are only ready to mate around two to three years later. The males become sexually mature at around eight to twelve years of age. First of all, young males are called "black back" until they have developed into silverbacks in the course of the maturation period up to the age of about twelve years. They reach their full height around the age of 15.Most young gorillas leave their birth group during puberty (see chapter Lifestyle).

In the case of gorillas, the competition between males for females is very great. In groups with a single silverback, the latter is the only one entitled to all females in his group. In groups with multiple silverbacks, the dominant silverback has priority over the females in the group and aggressively defends them against the other males. Nevertheless, they try to approach the females unnoticed again and again. Genetic studies show that lower-ranking males can also produce offspring. Mating is initiated by both the males and the females. Sometimes the females are forced to mate by the males, especially the dominant silverback. According to a study in the Volcano National Park in Rwanda, the dominant silverbacks were involved in 83 percent of the matings and 79 percent of the females mated with multiple males. Dominant silverbacks prefer to mate with adult females, lower-ranking males most often with subadult females. There are probably two reasons for this connection: On the one hand, older females already have experience with rearing a boy and thereby increase the likelihood of greater reproductive success for the male. Second, it is a strategy to reduce inbreeding between fathers and daughters who do not leave their birth group. When young, non-migrated females, who are most likely the daughters of the dominant silver back, prefer to mate with young and lower-ranking males, they avoid getting pregnant by their fathers.

Mating occurs all year round, but is still rare overall, as the females are mostly pregnant or suckling. The sexuality of the gorillas includes both dorso-ventral and occasionally ventro-ventral positions during sexual intercourse. Males without a group do not reproduce.

After a gestation period of eight to nine months, a single young is usually born. The umbilical cord bites through the female's teeth and eats the placenta. Gorilla infants are very dependent on the care of their mothers and are suckled for about three to four years in Eastern gorillas. In the first few weeks of life, the females carry their offspring on their stomach, then on their backs until they are weaned from breast milk. The eastern gorilla mothers share their sleeping nests with their children until they are expecting their next offspring after around three to five years. As long as the females are suckling, they are not ready to conceive. Overall, the mothers take on a large part of the rearing of the offspring, but the silverbacks also take care of the children in between. Boy mortality is greatest in the rainy season due to the higher rate of respiratory infections. Overall, over 70 percent of the gorilla children of Eastern gorillas survive the first three years of life. The first child has a significantly lower probability of survival than the children of experienced mothers. Female gorillas usually raise around three to four children successfully in their lifetime. The life expectancy of Eastern Gorillas is believed to be over 40 years.

Where do eastern gorillas live?

Their area of ​​distribution then and now

Eastern gorillas have the smallest range of the African great apes. The distribution areas of the eastern and western gorillas are separated by a distance of around 900 kilometers. The distribution areas of the two subspecies of the Eastern gorillas are also isolated from one another, but nonetheless adjacent. Eastern lowland gorillas are found exclusively in the eastern part of the Democratic Republic of the Congo. Their distribution area stretches from the flatlands east of the Lualaba River in the west to the Central African Rift in the east and from the northwest tip of Lake Eduard in the north to the northwest tip of Lake Tanganyika in the south. It is estimated that the Eastern lowland gorillas only inhabit around 15,000 square kilometers within this large region. The largest sub-populations live in the regions of Maiko, Tayna-Waluellen, Kahuzi-Kasese and the Itombwe massif. The historical distribution area of ​​the eastern lowland gorillas probably covered approx. 112,000 square kilometers.

Mountain gorillas are found almost exclusively in five protected areas in the eastern part of the Democratic Republic of the Congo, in the north-west of Rwanda and in the south-west of Uganda. Their total stock is divided into two populations, which live only 25 kilometers away, but are completely isolated by dense settlement and intensive agriculture. One population is located in the border area of ​​the three distribution countries in the region of the Virunga volcanoes in the three protected areas Volcano National Park in Rwanda, Virunga National Park in the Democratic Republic of the Congo and Mgahinga Gorilla National Park in Uganda. The distribution area of ​​the Virunga population covers an area of ​​around 375 square kilometers. The other population inhabits the Bwindi National Park in southwest Uganda and the adjacent Sarambwe Reserve in the Democratic Republic of the Congo. The distribution area of ​​the Bwindi population is significantly smaller and has an area of ​​only around 215 square kilometers.

In which habitat do eastern gorillas occur?

The name Eastern lowland gorillas is a misnomer, because these alleged lowland dwellers also occur in the mountains. They live in tropical lowland rainforests, secondary forests, mountain forests, bamboo forests, swamp forests and in peat bogs. They can be found at altitudes of 600 to 2,900 meters. This means that eastern lowland gorillas of all gorillas occur in most different altitudes.

Mountain gorillas are native to the region of the Virunga volcanoes in various mountain forests, bamboo forests, mixed forests and grasslands in the summit region of the volcanoes at altitudes of 1,850 to 3,800 meters. If they are disturbed by people, they also move to deeper regions. The region of the Virunga volcanoes is characterized by large amounts of precipitation and fertile soil. In the Bwindi region, the mountain gorillas inhabit mixed forests at altitudes of over 1,100 meters in the mountains. Their habitat is characterized by many steep slopes and dense undergrowth. In addition, there are more fruit-bearing trees in the Bwindi region than in the habitat of the Virunga mountain gorillas.

How do eastern gorillas feed?

Everything about their food and diet

Gorillas are predominantly herbivores. Overall, their diet varies with the altitude of their range. Freshly sprouted bamboo shoots belong to the favorite food of the Eastern Gorillas. When these sprout from the ground twice a year at the beginning of the rainy season, both eastern lowland gorillas and mountain gorillas feed almost exclusively on them.

Eastern gorillas have a larger and seasonally different food spectrum in lower regions than at higher altitudes. In eastern lowland gorillas, fruits make up an average of around a quarter of their diet. This is a smaller proportion than that of western gorillas. They also eat leaves, plant pulp, bark, lianas, herbs and ants. The greater the proportion of fruit in the diet, the greater the distances the gorillas have to travel to find them. Some of the favorite plants of the eastern lowland gorillas belong to the typical vegetation of secondary forests. In addition, the gorillas of this subspecies repeatedly resort to nutritious crops such as bananas or sugar cane, which are grown on agricultural land. Eastern lowland gorillas eat most of the time on the ground, but also regularly in the trees.

Bwindi mountain gorillas also eat an average of around 25 percent of fruit. The variety of forage plants is different in the different altitudes, just like in the eastern lowland gorillas. According to studies, Bwindi mountain gorillas, which live in lower regions, eat fruits from a total of 36 forage plants and Bwindi mountain gorillas, which occur at higher altitudes, eat fruits from a total of only eleven different forage plants. Mountain gorillas in the region of the Virunga volcanoes, on the other hand, can hardly find fruit, but instead eat leaves, plant pulp, bark, stems, roots and ants. In a study on the diet of the Virunga mountain gorillas, a total of 38 forage plants were found. 62 fodder plants are known in the entire range of the mountain gorillas. They prefer celery, thistles, nettles and bed herbs. Three fodder plant species, which can be found almost always and everywhere in their habitat, make up three quarters of their diet. In order not to injure themselves on the spines and thorns of some plants while eating, they have developed clever techniques. Thistle leaves, for example, roll them up or fold them up so that the spines are hidden. Overall, the nutritional value of the food of the Virunga mountain gorillas is particularly low and the digestive effort is high at the same time, so that they eat about half the day and have to rest for the rest of the day. It is believed that food competition with chimpanzees has led to niche formation and increased leaf-eating by gorillas.

Gorillas get most of the fluids they need from their food and therefore seldom drink. They have also been seen catching raindrops in their mouths or brushing them off their fur.

As “seed taxis”, gorillas play an important role in their ecosystem. The sowing of some plants is dependent on dispersal by gorillas, including large trees, the fruits of which are an important part of the food web. Ultimately, through their diet, gorillas, as "gardeners of the rainforest", help to preserve biodiversity and to regenerate forest areas.

How many Eastern Gorillas are there?

Their existence in the past, present and future

All four gorilla subspecies are in bad shape, but in numbers the eastern gorillas are far inferior to the western ones. With a total population of less than 5,000 animals today, they are the rarest great ape species in the world. The mountain gorillas are even rarer than the eastern lowland gorillas.

In 1995 the total population of the Eastern lowland gorillas still numbered 16,900 individuals. Around 86 percent of the population lived in the Kahuzi-Biega National Park and the neighboring Kasese region. But years of unrest and instability in the Democratic Republic of the Congo and neighboring countries as well as the hunt for bush meat, especially in the vicinity of mostly illegal mining camps, have decimated the Eastern lowland gorillas. In the eastern part of the Kahuzi-Biega National Park, almost half of the gorillas living there died between 1996 and 1999. In 2015 there were only around 3,800 gorillas of this subspecies. Thus, within 20 years, more than three quarters of the total population has been lost. The remainder live in many, sometimes extremely small, sub-populations. In a small wooded area on Mount Tshiaberimu in the Virunga National Park in the Democratic Republic of the Congo, for example, there is a population that counted 18 Eastern lowland gorillas in 2008 and of which only individual animals are still alive today. Examinations of the population show that the rate of decline in the entire range of the eastern lowland gorillas is still around five percent per year.

Mountain gorillas are the only great apes whose numbers have continuously increased in recent years. Their total population is nevertheless extremely small and in 2018 only counted around 1004 animals. Around 604 mountain gorillas live in the Virunga volcanoes and around 400 in the Bwindi region. In the region of the Virunga volcanoes, the population of mountain gorillas was at its lowest point in 1981 and there were only about 254 animals. Since then, the Virunga mountain gorillas have been recovering increasingly. By 1989 the population rose to around 324 animals, by 2000 to around 359 animals, by 2003 to around 380 animals and by 2010 to around 480 Virunga mountain gorillas. In the Bwindi region around 300 mountain gorillas had been counted in the 1990s and around 315 in 2002.

Are Eastern Gorillas Endangered?

Your endangerment and protection status

According to the IUCN Red List, Eastern Gorillas are critically endangered. They are listed in Appendix I of the Washington Convention on the Protection of Species. Any international commercial trade is therefore prohibited. In addition, they are protected under national law in all of their distribution countries.

The distribution countries of the Eastern Gorillas have been plagued by political unrest and wars, which also affect the gorillas, since the early 1990s. In addition, the distribution area of ​​the Eastern Gorillas is one of the regions with the greatest population density in Central Africa. The eastern part of the Democratic Republic was already densely populated in the early 1990s. In 1994, around one million people fled the genocide in Rwanda to the neighboring Democratic Republic of the Congo and sought refuge near the Virunga National Park and Kahuzi Biega National Park protected areas. Furthermore, the range of the eastern gorillas is rich in mineral resources, including diamonds, copper, cobalt, gold and coltan. The income from the mining of these mineral raw materials is repeatedly invested in weapons and warfare by the various military units and rebel groups. In the period between 1998 and 2000 alone, workers to mine Koltan settled near the Kahuzi-Biega National Park and the Okapi Wildlife Reserve, and thousands of them immigrated here with their families and accompanied by professional poachers. All of these people increased the hunger for land and the need for food.
In the ranking of the "Human Development Index", a prosperity indicator of the United Nations, the Democratic Republic of the Congo was ranked 176 out of 188, Rwanda 159 and Uganda 163. For the Eastern Gorillas, the violent conflicts had several negative consequences. Their living space was a hideout and a retreat for rebels. The habitat came under pressure from firewood collection, the extraction of building materials, and mining and land use changes. All of this has meant loss of habitat (see below) and ongoing disturbance for the gorillas. The large number of people and the loss of state control exacerbated the bushmeat problem (see below). Ultimately, the work for nature conservation organizations and ministries as well as for research was made difficult or even impossible in the meantime.

Overall, poaching, habitat loss, disease and the effects of climate change are the greatest threats to Eastern Gorillas today. Due to the low reproductive rate, the long phase of dependence of the young on their mothers and the late sexual maturity, gorillas find it difficult to compensate for population losses.

Poaching has posed the greatest threat to the Eastern lowland gorillas in recent years. In the 1990s and early 2000s, the Virunga mountain gorillas were also affected by poaching. In many regions, the animals of the Central African forests are an important source of food for the population because the protein needs of the population in many rural regions cannot be covered by livestock farming. But the hunt for bush meat in the Democratic Republic of the Congo has long since ceased to be sustainable due to the many crises and high demand. Poaching is also carried out in protected areas. Although gorillas have traditionally been hunted for human consumption only very rarely and, like all other great apes, are under protection, thousands of Eastern lowland gorillas have died from bushmeat poaching in recent decades. To their disadvantage, gorillas are relatively easy to capture with firearms and bring a comparatively large amount of meat. Illicit gun possession is widespread in the Democratic Republic of the Congo. Bushmeat hunters who previously hunted in the traditional way now have a significantly higher yield by hunting with firearms. In addition, gorillas get caught in the traps and snares of the poachers, which are actually laid out for other animals. Should the gorillas manage to free themselves from such a trap or snare, they face fatal infections or remaining physical disabilities such as a severed hand or a missing foot. In the period between 1971 and 1998 alone, there were 50 cases of three gorilla groups in the volcano national park in Rwanda in which gorillas were injured with snares, four of them with fatal consequences. In the Kahuzi Biega National Park in the Democratic Republic of the Congo, there are some Eastern lowland gorillas with a hand severed by a noose.

The bushmeat trade is not the only reason for illegal gorilla hunting, however. Their body parts are also processed and sold as souvenirs, for example their hands as ashtrays or their heads as wall trophies.Although the live animal trade is also prohibited, there is also a black market in some regions for live gorillas as well as other great apes that are illegally sold as exotic pets or end up in the entertainment industry such as private zoos, circuses and amusement parks. Young animals in particular are tourist attractions and popular accessories for photo sessions. According to a 2015 study by the organization GRASP, over 1,800 great apes captured for trade, including 98 gorillas, were found between 2005 and 2011. But that's only the tip of the iceberg. Experts believe that more than 22,000 great apes were actually caught in Africa and Asia during this period, and an average of 420 gorillas per year. There is a complex network of poachers, smugglers and traders across countries and continents. In the period between 2007 and 2012, for example, ten gorillas with forged papers were exported from Guinea, where they are not native, to China. The ape trade is a lucrative business. For example, in 2002 a zoo in Malaysia purchased gorillas for $ 400,000 per animal. The "cuddly" mountain gorillas are particularly popular with the Eastern gorillas. In the region of the Virunga volcanoes there were numerous and since then individual cases of captive mountain gorilla juveniles. With gorillas the removal of single individuals leads in many cases to further deaths in the group and ultimately to a weakening of the population. If young animals are to be caught, their parents protect them with their own lives. Often times, when a silverback dies, the group disintegrates and any dependent pups are likely to fall victim to infanticide.

It is believed that the habitat loss in the range of the Eastern lowland gorillas is greatest compared to that of the other gorilla subspecies. According to estimates, they have already lost 87 percent of their historical habitat. The main cause is the extensive conversion of living space into agriculturally used areas. In addition, there is the extraction of natural raw materials, in particular the sometimes illegal mining of mineral resources, logging and the production of charcoal. As a result, the range of the eastern gorillas is becoming more and more fragmented and the subpopulations are increasingly becoming isolated. This also reduces genetic exchange. Due to the current crisis, there is currently no industrial logging. However, this could change as soon as the situation in the Democratic Republic has stabilized. When gorillas occasionally eat from the farmers' fields and plantations near their home areas, they often kill them in revenge for their crop failures.

Epidemics of disease represent a further threat to the gorilla population. Just like other great apes, gorillas can be infected with natural pathogens such as Ebola and also with human-borne diseases such as respiratory infections and intestinal diseases, which are harmless to humans but are harmless to gorillas can be fatal. As scientists suspect, Ebola fever has cost the lives of many great apes in Central Africa in recent years. Although there are no known cases of Ebola outbreaks in Eastern gorillas, they represent a potential threat. Through the presence of people, including rangers, researchers, tourists, workers, hunters and local residents, the gorillas repeatedly come into contact with pathogens against which they have no immunity. That is why most of the protected areas have strict rules to protect the health of wild animals.

In the region of the Central African Rift, negative effects from the consequences of climate change are also to be expected in the future for the eastern gorillas. It is believed that habitat quality and food availability will decrease as temperatures rise and rainfall patterns change.

Gorilla protection has been a major topic for the WWF for decades. Like chimpanzees, bonobos, orangutans, polar bears, rhinos, elephants, giant pandas and other species, gorillas are among the flagship species of the World Wide Fund for Nature. The WWF is active worldwide in numerous projects for the protection and research of threatened species and has already achieved a great deal. Further information about the project work can be found at: www.wwf.de/themen-projekte/bedrohte-tier-und-pflanzearten