Study unveils simple indicators to measure wildlife degradation in African forests

Medium- to large-bodied mammals play crucial roles in tropical ecosystems, acting as herbivores, seed dispersers and predators. However, these species are also prime targets for hunters, leading to significant changes in wildlife communities. Now an international study shows that overhunting causes predictable shifts, with larger, slow-breeding animals disappearing first, while smaller, more resilient species like rodents become more dominant.

To understand these shifts, the researchers conducted extensive fieldwork in Gabon, using systematic camera trapping and hunter offtake records. They collaborated with 314 hunters from ten communities, recording data from nearly 13,000 hunting trips. By comparing the wildlife composition in hunted areas with that in protected reference sites, such as Ivindo National Park, the team developed reliable indicators of faunal degradation. This valuable research was funded by the European Union through the Sustainable Wildlife Management (SWM) Programme.

Key indicators for conservation
 

The study identifies two main indicators that are simple yet powerful tools for monitoring wildlife degradation:

• Rodents-to-Ungulates Ratio: This ratio increases significantly in heavily hunted areas, reflecting a higher presence of smaller, more resilient species.
• Mean Body Mass of Offtake: This metric decreases as hunting pressure intensifies, indicating a decline in larger species.

These indicators are not only easy to calculate but also practical for implementation through community-led monitoring programmes. They provide valuable insights for conservationists and local communities to track and manage the health of their ecosystems.

Implications for conservation and policy
 

The findings underscore the importance of involving local communities in wildlife monitoring and management. Hunters, with their deep knowledge of the forest, can play a critical role in gathering data and ensuring sustainable practices. This community-based approach aligns with global conservation goals, such as the Global Biodiversity Framework’s “30×30” target, which aims to protect 30 per cent of the world’s land and water by 2030.

The study's first author, Dr Davy Fonteyn, from CIRAD and the Gembloux Université de Liège/Belgium, emphasises: “By leveraging the expertise of local communities and using these straightforward indicators, we can make significant strides in conserving wildlife and maintaining ecological balance in tropical forests.”

The researcher who coordinated the study, Daniel Cornélis (CIRAD), continues: “By integrating camera-trap and hunting offtake data, we established that the most reliable hunting indicators for assessing alteration in wildlife assemblages are also the easiest to calculate! These results offer a promising way of simplifying hunting monitoring, facilitating its adoption by local communities.”

The researchers advocate for scaling up this approach across other tropical regions, adapting the indicators to different ecological contexts. They also call for the integration of these methods into broader conservation strategies, including the establishment of community-use zones and the protection of large-scale ecological connectivity.

The Sustainable Wildlife Management (SWM) Programme 
 

The SWM Programme is a major international initiative that aims to improve the conservation and sustainable use of wildlife in forest, savannah and wetland ecosystems. It is being funded by the EU with co- funding from the French Facility for Global Environment (FFEM) and the French Development Agency (AFD). Projects are being piloted and tested with governments and communities in 16 participating countries. The initiative is coordinated by a dynamic consortium of four partners, namely the Food and Agriculture Organization of the United Nations (FAO), the Center for International Forestry Research and World Agroforestry (CIFOR-ICRAF), the French Agricultural Research Centre for International Development (CIRAD) and the Wildlife Conservation Society (WCS).

(CIRAD/wi)

Reference:

Fonteyn, D., Fayolle, A., Fa, J. E., Vanthomme, H., Vigneron, P., Vermeulen, C., Malignat, R., Konradowski, B., Yia Okanabene, M. N., Dibotty-di Moutsing, S. A., Pereira Dias, S., Deniau, C., Cornu, G., Groschêne, M., & Cornélis, D. (2024). Hunting indicators for community-led wildlife management in tropical Africa. npj Biodiversity. 

More information:

Link to the SWM Programme