The Yangambi Biosphere Reserve, located in northern Democratic Republic of Congo (DRC), was once a lush forest landscape rich with such wildlife as elephants and okapis. However, prolonged conflict and its cascading effects, including lack of economic opportunities and mismanagement of natural resources, have taken a toll on the local wildlife population.

Defaunation, defined as the loss of animals in all forms, including by extinction, extirpation, or population decline, is a common problem in tropical regions across the globe. However, due to conflict-related turbulence, DRC faces exceptional challenges from a conservation perspective. First, the presence of armed groups in the forest has increased hunting and trafficking of ivory, skins and meat, according to a new research paper by scientists with the Center for International Forestry Research (CIFOR). Second, protracted conflict has led to the degradation of the economic and social conditions of local inhabitants, who face limited economic opportunities and recurrent food insecurity, the paper states.

With these challenges in mind, the new study, carried out in the landscape of Yangambi with the support of the European Union, shows how local knowledge can be a powerful and inexpensive means to better understand defaunation within changing socioecological systems. CIFOR scientists interviewed members of local communities, particularly hunters, who described changes observed in species abundance and distribution, as well as the social and ecological factors that explain them.

“Local extinctions or sharp declines in mammal populations in the studied landscape are either the direct or indirect consequence of the rebellions that took place between 1996 and 2002,” explained Nathalie Van Vliet, CIFOR researcher and main author of the study. “We thus asked hunters to share their views on wildlife population trends from 1995 to 2018. They shed light on wildlife distribution across the landscape and the last observations of species that have either been locally extirpated or become rare.”

CIFOR scientists and hunters worked together through a participatory mapping process, which allowed them to spatially locate the main hunting camps and trails where wildlife had been recently spotted. “We did numerous field trips for 60 consecutive days. This hands-on experience of the area allowed us to locate on a map each of the last observations mentioned by hunters,” said Jonas Kambale Nyumu, who was also part of the research team.

The researchers asked the local hunters to list the main mammal species present in the studied landscape or locally disappeared since 1995. Then they discussed the evolution of these species and the main factors explaining these changes over time. “The participants had clear memories. We matched local names with scientific ones and were able to corroborate the information provided by the hunters,” Van Vliet said.

THE ACCOUNT OF THE DAMAGES

Through this exercise, local hunters provided a clearer picture on the severity of the wildlife depletion process in the landscape. “Our research showed that elephants have completely disappeared locally; other mammal species such as chimpanzees, red colobus and orycteropus have been significantly depleted; while okapis and forest buffalos only persist in the northern part of the landscape”, said Jonas Muhindo, another member of the research team.

Nevertheless, the observation that some vulnerable and emblematic species such as chimpanzees are still present in Yangambi, can give hope to conservationists.

“This is a demonstration of the resilience of natural systems facing sustained and increased anthropogenic pressures,” Van Vliet said. “It provides a positive vision about the likelihood to reverse trends as long as critical functions are preserved,” she added.

   Camera traps recently confirmed the presence of chimpanzees in Yangambi, as previously observed by local hunters. CIFOR

   Bushmeat trade has increased due to population growth in Yangambi and nearby villages. CIFOR/Axel Fassio

UNDERSTANDING THE ROOT CAUSES OF DEFAUNATION

The study also explains the factors behind wildlife loss as observed by local hunters, providing a more complicated picture than the scientists anticipated.

Most hunters identified the presence of armed groups in the forest as a direct cause of wildlife extirpation. Troops practiced hunting to feed themselves and for trafficking, affecting specially the okapi, leopard, buffalo, and elephant populations.

Furthermore, the economy of the region was significantly affected by political instability. Security concerns limited the movement of goods and people, existing factories closed, and government jobs were cut. Given the lack of employment and alternative sources of income, more families became dependent on forest resources for food security.

Other factors also led to a surge in hunting. First, population growth, especially in nearby cities, led to an increase in demand of wild meat. Second, the average age of entry into hunting has decreased over time. Third, access to weapons and headlamps has become easier.

“As a result, the number of hunters in the villages gradually doubled in 20 years and hunting now occurs both during the day and at night,” van Vliet said. As a result, previously unreachable species, such as nocturnal mammal and arboreal species (small monkeys and birds), have also become more vulnerable.

NEXT STEPS

CIFOR’s study not only evidences the level of complexity involved in defaunation, but it calls for its understanding to guide the development of effective conservation and restoration strategies. “Embracing the complexity explaining wildlife population trends is important to enable more accurate predictions of when and where collapses will occur and to guide the development of effective conservation and restoration policies,” Van Vliet said.

“We also need to explore how the wildlife depletion process can be reversed in a post-conflict context,” she adds. “We must identify the levers that can inverse the cascading effects of conflict to allow species to recover.”

To address these issues, the project FORETS (Formation, Recherche, Environnement dans la Tshopo) led by CIFOR and funded by the European Union, is working to create livelihood alternatives for local populations, increase the supply of meat from domestic animals, and in general promote a more sustainable management of the natural resources of the landscape.