Mountain Gorilla


Introduction

There are two species of gorilla, the eastern gorilla (Gorilla beringei) and western gorilla (Gorilla gorilla), which are geographically separated by the inner Congo Basin.  The eastern species of gorilla consists of two sub-species, the mountain gorilla (Gorilla beringei beringei) and eastern lowland gorilla or Grauer’s gorilla (Gorilla beringei graueri).

These two gorilla species have numerous similarities: both are large-bodied with adult males weighing up to 200kg and females around half that. In both, adult males are known as “silverbacks” due to the characteristic silver hair that develops on their backs from maturity. Gorillas are almost completely vegetarian, unlike chimpanzees. They live in social groups of between 7 and 16 individuals, comprised of one dominant silverback male, three or four females, and four or five of their offspring. However, large groups of almost 40 individuals have been encountered. Gorillas usually sleep in nests that they have built on the ground, although sometimes they nest in trees. Gorillas live up to 50 years. They are peaceful animals, but can be aggressive, particularly the silverback, who will fiercely defend his family.

Where they can be found

The mountain gorilla is found in two isolated subpopulations, the first within the Virunga Volcanoes region straddling the border between Rwanda (Volcanoes National Park), Uganda (Mgahinga Gorilla National Park), and the Democratic Republic of Congo (Virunga National Park), and the second within the Bwindi Impenetrable National Park (Uganda) and adjacent Sarambwe Nature Reserve (DR Congo).

The Virunga mountain gorillas are the best known of all gorilla populations, having been studied since 1967 and made famous through the work of primatologist Dian Fossey. The most recent survey in 2016 shows that the population has increased to 604 individuals from an estimated 480 in 2010. When combined with published figures from Bwindi Impenetrable National Park, this brings the global wild population of mountain gorillas to an estimated 1,004 and makes it the only great ape in the world that is thought to be increasing in population. Considering the positive trend, mountain gorillas are now listed as Endangered on the IUCN Red List. Mountain gorillas are also listed under Appendix I of the Convention on International Trade in Endangered Species of Fauna and Flora (CITES). CITES prohibits the international trade of Appendix I species, apart from exceptional cases.

Why they are important

Mountain gorillas and humans share a common ancestry, and apart from chimpanzees and bonobos, are more alike to us than any other species on Earth. They and other primates hold the key to understanding our evolutionary past. Increasingly, mountain gorillas are a prized ecotourism destination, generating income for all three governments and contributing significantly to local development.

How they are threatened

Despite an increasing population, mountain gorillas are still exposed to direct threats from illegal wire or rope snares (which are intended to ensnare other species but can kill or maim gorillas). There are also new threats including climate change, infrastructure development and the ever-present spectre of disease, which has the potential to devastate the remaining populations. Ongoing conflict and civil unrest in the region also present an ongoing risk, impacting people and wildlife. Apart from being highly biodiverse, the region as a whole is endowed with rich mineral and forest resources, and being volcanic, is highly fertile for agriculture. The region has one of the highest population densities in Africa, with more than 600 people per km2 in the areas adjacent to mountain gorilla habitat. Pressure on the landscape and on the natural resources in the region is very high.

How Vanishing Treasures is addressing the problem

The Vanishing Treasures programme focusses its efforts on mountain gorillas within Rwanda and Uganda, and will work with the protected authorities and adjacent communities of the Volcanoes National Park (Rwanda), and Mgahinga Gorilla National Park (Uganda) and Bwindi Impenetrable National Park (Uganda). While the programme will not be implemented in the DR Congo, it is anticipated to involve colleagues from the country in technical meetings.

Vanishing Treasures will work to better understand the diverse impacts of climate change on communities, gorillas and their habitats, as well as current and possible future vulnerabilities and responses. Programme activities will include measures to reduce human-wildlife conflict, as well as sustainable buffer zone and land management. The ultimate objective is to ensure the co-existence of people and wildlife in these times of rapid climate and environmental change.