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Gorilla
Gorilla

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CONSERVATION STATUS

CITES: Appendix I (What is CITES?)
IUCN Red List: G. gorilla: CR; G. beringei: EN (What is Red List?)
Key: CR = Critically endangered, EN = Endangered
(Click on species name to see IUCN Red List entry, including detailed status assessment information.)

Gorilla
Gorilla gorilla gorilla
Photo: Bryan Lenz

All gorillas face a very high risk of extinction in the wild in the near future if current threats do not subside. Hunting, forest clearance for agriculture and timber, and disease are the main threats to gorilla survival and these problems continue to increase in intensity and extent. Gorillas, like many African primates, are also subject to human warfare in parts of their range.

CONSERVATION THREATS & POTENTIAL SOLUTIONS

Threat: Human Induced Habitat Loss and Degradation

Habitat loss and modification due to human activity is a primary threat to gorilla survival. Agriculture, logging, fuelwood and forest product collection, and grazing domestic animals all degrade gorilla habitat and are problems that only increase as the human population in Africa grows (Plumptre et al. 2003). Only about 20% of gorillas live inside protected areas where, in theory, they are safe from habitat modification by encroaching humans. The remaining 80% are severely threatened by human induced habitat modification (Harcourt 2003). Mountain gorillas, while numbering only a few hundred, live in well-protected national parks known as the Virunga Conservation Area comprised of Parc National des Virunga, Parc National des Volcans, and Mgahinga Gorilla National Park (Steklis & Gerald-Steklis 2001). Habitat destruction has subsided in this area in recent years (Tutin & Vedder 2001; Plumptre et al. 2003). The growing human population on all sides of the mountain gorillas' habitat allows for little buffer between the apes, and human activities like cattle grazing and collection of forest products have been problematic in the past and may become so in the future if political instability results in another civil war (Oates 1995; Steklis & Gerald-Steklis 2001).

Eastern lowland gorillas living in war-torn DRC are losing habitat faster than any other gorilla population (Plumptre et al. 2003). Logging, agriculture, and livestock grazing are all important economic activities for humans that lead to habitat modification in the eastern lowland gorilla's range. Lowland populations are being forced into higher altitudes where steep slopes are not conducive to farming or ranching, isolating the population even further (Ilambu 2001). Following wars in 1996 and 1998-99, a huge influx of refugees from Rwanda compounded the problem as more pressure was put on the forest for fuelwood and food collection. The potential far-reaching effects of this sudden increase in human population will not be known for some time (Ilambu 2001; Tutin & Vedder 2001). Mining prospects in DRC are also having devastating effects on the habitat and gorilla population (Stoinski pers. comm.). Ecotourism can be a positive, revenue-earning undertaking for some communities, but when poorly managed can have negative impact on the animals or ecosystems it has been implemented to save. In the case of eastern lowland gorillas, ecotourism has had a negative impact on the gorillas and their habitat. Implemented as a source of revenue for local communities, the large groups of frequent visitors severely impacted high-altitude vegetation and were disturbing to the gorillas (Tutin & Vedder 2001).

The majority of western gorillas live outside protected areas and are therefore most at threat from human induced habitat modification. Fortunately, though, where gorillas exist in the remote forests of the Congo Basin, they are not subject to human disturbance. Interestingly, though, gorillas can coexist with logging because they tend to favor the areas of secondary vegetation that grow after an area has been clear cut (White & Tutin 2001; Plumptre et al. 2003). Unfortunately, with logging comes habit fragmentation by logging roads and easy access by hunters. Forest products are in increasing demand in some parts of their range where human populations are high and continuing to grow, including Nigeria (Cross River gorilla), southern Congo, and parts of Equatorial Guinea (Tutin & Vedder 2001).

Potential Solutions

Great strides have been made in reversing the population decline of mountain gorillas. With the support of notable gorilla researcher Dian Fossey, the Mountain Gorilla Project was launched in Rwanda in 1979 and included multiple approaches to conservation including education, ecotourism, and patrols to keep people and cattle out of the protected habitat (Steklis & Gerald-Steklis 2001; Tutin & Vedder 2001). While the Mountain Gorilla Project became the International Gorilla Conservation Program and continues its work today, many other organizations have been involved in similar programs aimed at educating local people, mountain gorialls have become a source of regional and national pride in Rwanda (Tutin & Vedder 2001).

More security is needed surrounding the Kahuzi-Biega National Park, where eastern lowland gorillas are studied (Tutin & Vedder 2001). Though ecotourism was successful at this site at one time, poor management led to the disturbance of the gorilla population and the destruction of habitat. Because the interest still exists and it is quite a lucrative undertaking, well-managed ecotourism operations focusing on small groups of visitors at infrequent intervals may revive the local economy of this area of DRC. Unfortunately, political instability in the region may prevent this option currently, and some effort should be made to secure the region from encroachment of human populations that extract forest resources, by using guards and continued presence of researchers. Columbotantalite (also called Coltan) reserves scattered throughout DRC have also drawn thousands of people into gorilla habitat, affecting the gorilla populations. An ore used to make semiconductors for electronics, including cell phones and computers, in the late 1990s coltan was sold for US$80 per kilogram and was an attractive prospect for people who made less than US$30 per month (Plumptre et al. 2003). Unfortunately, huge reserves of this ore are found in Kahuzi-Biega National Park and thousands of settlers in mining camps severely affected the local population of eastern lowland gorillas.

Western lowland gorillas that occupy swamp habitats that are unsuitable for commercial logging and are difficult to access by local people trying to extract forest products during the rainy season should be the focus of conservation activities. These areas have high population densities of gorillas and should be protected from future human incursion (Tutin & Vedder 2001). Though it is a difficult task to convince people to protect a population that is not currently severely at risk, it must be emphasized that these populations are healthy and will remain that way only if they are unharmed by habitat destruction in pristine forests (Tutin & Vedder 2001). Where western lowland gorillas are threatened by agriculture and selective logging (southern Republic of Congo and Equatorial Guinea), efforts should be made to establish protected areas in congruence with active field research sites. The major parks that have been established in western lowland gorilla range include Dzanga-Sangha National Park in CAR and Nouablale-Ndoki National Park in Congo (Tutin & Vedder 2001). Another key area that has not attained protected status is Lopé Faunal Reserve in Gabon where researchers have worked hard to habituate the gorillas.


Threat: Invasive Alien Species

Gorillas are highly susceptible to human diseases, and where they are immunologically naïve, the influx of poachers, soldiers, local communities, and domestic animals facilitates the spread of pathogens in small communities (Mudakikwa et al. 2001; Plumptre et al. 2003). Gorillas in Republic of Congo and Gabon are currently threatened by an epidemic of Ebola hemorrhagic fever. Even in the most remote areas of their region, western gorilla populations have declined in congruence with human outbreaks of the disease and carcasses found have tested positive for Ebola (Walsh et al. 2003).

Some other examples of zoonotic transfer include an epidemic of scabies, or sarcoptic mange, documented among a group of mountain gorillas in Bwindi Impenetrable National Park, the entire group was infected and it resulted in the death of an infant while respiratory illness claimed the lives of six mountain gorillas in the Virunga Volcanoes in 1988 (Wallis & Lee 1999). In the Virunga Conservation Area, emergency medicine and preventative health monitoring has been conducted by the Mountain Gorilla Veterinary Project since 1985 (Mudakikwa et al. 2001). The major groups that pose unique disease risk for mountain gorillas include local people, conservation personnel, and ecotourists (Mudakikwa et al. 2001). Though contact between gorillas and local people is limited to when they enter the park illegally or when gorillas leave the park boundaries and raid crops, this is significant enough to spread disease to the vulnerable gorillas including scabies, respiratory tract infections, intestinal parasites, skin disorders, and measles (Mudakikwa et al. 2001). Diseases are also transferred between park staff and tourists and gorillas as well, and while precautions are taken, this still poses a threat to the health of mountain gorillas.

Potential solutions

Educating local communities about zoonotic diseases may decrease disease transfer, and ideally, providing more widespread access to health care would also be useful. Where gorillas come in contact with researchers, park visitors, and staff, implementing even stronger protocol that includes face masks, gloves, required immunization, and further required distances from the animals may also decrease chances of disease transfer (Butynski 2001). Currently, field personnel working with the research populations of mountain gorillas take part in an employee health program designed to limit disease transfer to gorillas (Stoinski pers. comm.). In populations as small as the mountain and Cross River gorilla's, it is imperative to minimize the possibility of infectious disease transfer as this could eliminate both populations entirely.

Research on vectors of and vaccines for the Ebola virus are necessary to alleviate both human and ape suffering in regions where outbreaks occur (Walsh et al. 2003). Coupled with epidemiological research, law enforcement is necessary to prohibit contact between humans and apes, especially in targeted regions. This includes forecasting disease movement (among both humans and gorillas), anticipating where the next outbreak is likely to occur, and implementing strict policies and effective law enforcement measures to isolate potential outbreaks.


Threat: Harvesting (hunting/gathering)

More threatening than habitat loss in some areas, hunting of gorillas for meat as well as capture of animals for collections are other hazards greatly affecting gorilla populations across Africa. Where human populations encroach on gorilla habitat and forest products such as fuelwood and timber are sought, poaching is generally also a problem, either for food or for sale (Plumptre et al. 2003).

Mountain gorillas in the Virunga Conservation Area are heavily protected and although poaching had been reduced to zero), the past few years has seen a resurgence in poaching for infants for the pet trade (Stoinski pers. comm.).

People living in the range of eastern lowland gorillas have traditionally had taboos against eating gorillas, though these customs are being quickly replaced. Civil war in DRC has led to mass hunger in the area as well and more often eastern lowland gorillas are being eaten for subsistence (Plumptre et al. 2003). Mining coltan in Kahuzi-Biega National Park has also led to drastic declines in gorilla populations, not simply because of habitat disturbance, but because of subsistence hunting by the thousands living in mining camps (Plumptre et al. 2003). Insecurity in the region prevents guards from stopping this influx of people and hunting will likely continue if the price of coltan increases in the future.

Western gorillas that live in areas where logging activity is ever-increasing are also subject to hunting. Logging and the bushmeat market are inextricably linked and unfortunately, the social structure of western lowland gorillas makes them particularly susceptible to devastation by only a few hunters (Tutin & Vedder 2001). Entire groups of western lowland gorillas can be wiped out by a single or a few poachers. The silverback in a group will approach and display against any perceived threat, including poachers, and in doing so, he is an easy target and is quickly killed. Poachers will capture the infants for sale as pets, often killing the mother that is defending her infant (Tutin & Vedder 2001). Moreover, poachers are able to reach the dense, most remote areas of forests as logging companies establish roads and transportation from small towns and cities is available deep into the forests (Butynski 2001; Plumptre et al. 2003). Company employees living in small logging towns are able to afford meat, and it is often less expensive to purchase bushmeat than other sources of protein. Almost all facets of the bushmeat trade are controlled or facilitated by logging companies: they sell guns and ammunition, provide cable for snares, transport poachers into the forests on trucks, carry the meat out on trucks, employees purchase it in town, and boats and trucks transport the meat to larger markets in cities (Butynski 2001; Wilkie & Carpenter 2001).

Potential solutions

Economic value must be given to live gorillas if local communities are to stop pursuing them for meat. Alternately, world aid and development organizations must give fiscal incentives for gorilla-friendly development projects that include alternate protein sources. Education of local communities or stakeholders is also necessary if the bushmeat trade is to subside. Including stakeholders in research at field stations, guard duties, or education programs are all ways of providing economic opportunities and incentives for protecting gorillas as well as creating a bond between people and apes.

Foreign logging companies must also be held accountable by the global community for their role in the bushmeat trade. Boycotts of tropical hardwoods in developed countries that purchase lumber from these companies or cancellation of logging concessions in countries where companies are actively involved in transporting bushmeat could help (Butynski 2001). Furthermore, gorilla-friendly certification programs by independent consultants could validate the practices of logging companies and provide an alternative to western consumers that are interested in tropical wood (Butynski 2001).

In situ refuges and sanctuaries for orphan gorillas confiscated from markets play an important role in assisting law enforcement and as education centers for local people.


Threat: Accidental Mortality

The bushmeat market targets more animals than primates, snares and traps are set for duikers, pigs, and rodents as well (Mudakikwa et al. 2001; Wilkie & Carpenter 2001). Unfortunately, snares are frequent causes of human-induced injuries to gorillas and can lead to loss of limbs or severely painful deaths if not treated (Mudakikwa et al. 2001). Gorillas that are caught in snares struggle to free themselves and are often cut on their limbs, hands, and feet; if these cuts become infected, without proper medical attention, the gorilla may likely die (Mudakikwa et al. 2001; Plumptre et al. 2003).

Potential solutions

Even with vigilant patrolling, snare removal is a constant challenge in areas where gorillas are sympatric with desirable animals (Hall et al. 1998; Plumptre et al. 2003). Mountain gorillas that encounter snares and are injured by them are treated by emergency medical staff of the Mountain Gorilla Veterinary Project. This process greatly decreases the chances of amputation and secondary bacterial infection. As the snare is removed, the wounds are cleaned and treated, and the injured animal is monitored to assess if follow up care is needed (Mudakikwa et al. 2003). Though there are great challenges and risks in undertaking this type of treatment for wild gorillas, it is a possibility for similarly habituated populations and has greatly reduced mortality caused by snare wounds among mountain gorillas. Snare patrols by researchers and field assistants coupled with intervention upon injury may decrease accidental mortality in gorillas.


Threat: Persecution

Large and imposing, gorillas are often perceived as dangerous by most humans who share their range and their image is not helped when they periodically raid plantations in some areas (Hart & Hall 1996; Tutin & Vedder 2001). Furthermore, gorillas that attack and seriously injure farmers on land adjacent to parks are even more despised and targets for retaliation (Butynski 2001).

Potential solutions

Public education programs about gorillas may increase tolerance for them in local communities that come in contact with them on farms and plantations. Teaching members of the community about the uniqueness of gorillas and the ecosystem services they provide coupled with compensation for injuries or crops that are lost or damaged may improve gorilla-human relationships in some areas.


Threat: Natural Disasters

Cross River gorillas live in a tiny fragment of forest in Nigeria and Cameroon where the dry season is long and the forest is susceptible to destructive fires. Fires started outside their range by local farmers, hunters, and pastoralists can get out of control and sweep through the dry forest, causing significant damage (Oates et al. 2003).

Potential solutions

Discouraging fire as a tool to clear land during this season is one approach to decrease the chance of forest fires. Limiting burning to certain times of year when the forest is not as vulnerable is another option to avoid devastating fires.


Threat: Changes in Native Species Dynamics

Though gorillas and chimpanzees have overlapping ranges at multiple sites throughout Africa, the two apes do not compete for access to resources, in fact, they actively avoid competition by exploiting different niches during different times of year (Kuroda et al. 1996; Yamagiwa et al. 1996).

The effect of leopard predation on gorilla populations is negligible (Fay et al. 1995).


Threat: Intrinsic Factors

Long interbirth intervals and high infant mortality make reproduction a slow process for all subspecies of gorillas. While these intrinsic factors do not limit population growth by themselves, when disrupted by disease, abnormally high infant mortality, stress from disturbance, and other environmental hazards, recruitment may dwindle (Butynski 2001; Tutin & Vedder 2001).

Higher mortality during the rainy season has been documented among mountain gorillas. Low temperatures coupled with heavy rainfall lead to conductive heat loss and respiratory infections (Watts 1998).

Severely isolated populations of gorillas are threatened by the effects of limited gene flow, restricted range, and low densities. Small populations are at risk of inbreeding depression, are vulnerable to stochastic events, and genetic fixation of deleterious alleles is possible (Oates et al. 2003).

Potential solutions

The establishment of well-funded, well-run national parks is essential to gorilla conservation. Given the challenges of protecting habitat in countries ravaged by civil war, where human populations often live in substandard conditions, with few if any government services, and law enforcement is limited, the international community will have to support conservation efforts (Plumptre et al. 2003). Integrated conservation and development programs may be useful tools in areas where human suffering leads to loss of biodiversity and international aid organizations must be willing to create projects that provide opportunities for people without sacrificing the integrity of conservation goals.

Maintaining corridors of habitat between fragments of forest in which the least numerate subspecies exist as well as strict protection of these areas from poachers and encroachment by human populations will help bolster gene flow (Oates et al. 2003).


Threat: Human Disturbance

War and civil unrest are indisputable causes of loss of biodiversity in Africa. Well armed insurgents seek refuge in forests, move between borders, set up camps and kill gorillas for subsistence usage or sport. Moreover, masses of displaced people seek food and shelter as they flee from violent conflict. This has resulted in large tracts of land being cleared for fuelwood, hunting of gorillas for food, and transmission of disease between humans and gorillas. While the extent of the damage following conflict is largely unknown, there are undoubtedly negative impacts on all subspecies of gorillas (Vedder et al. 2001; Plumptre et al. 2003).

Potential solutions

By looking at historical patterns of warfare and civil unrest, much can be learned about potential future threats to gorillas. For example, parks and reserves on country borders are extremely susceptible to becoming zones of military operations, park staff and their families are at very high risk if they remain to carry on their duties, and international monetary support is likely to dissipate as conflict heightens (Vedder et al. 2001). There are some positive lessons learned as well, though. Where ecotourist activities are important, less damage is likely to occur, in areas of long-term research and commitment, fewer losses are incurred, and the support and commitment of junior staff should not be underestimated (Vedder et al. 2001). While there are seemingly few solutions to the deep-rooted tensions in the region, conservationists should remain hopeful that the capacity for recovery, of both people and wildlife, is great and cannot be underestimated.

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Content last modified: October 4, 2005

Written by Kristina Cawthon Lang. Reviewed by Tara Stoinski.

Cite this page as:
Cawthon Lang KA. 2005 October 4. Primate Factsheets: Gorilla (Gorilla) Conservation . <http://pin.primate.wisc.edu/factsheets/entry/gorilla/cons>. Accessed 2014 September 2.