Long-term trends in wildlife community structure and functional diversity in a village hunting zone in southeast Cameroon

Hunting may be the greatest threat to wildlife populations across the Congo basin. Large-bodied species are the most vulnerable; alterations in assemblages of such keystone species can affect many important ecological functions. There may be a reduction or loss of ecological services, such as seed dispersal. Monitoring functional diversity within a wildlife community alongside descriptions of wildlife community structure (abundances and species richness) increases understanding of how well a system can withstand disturbance, or recover following it (i.e., its ecological resilience). Between 2002 and 2016, changes in wildlife abundance and diversity of functional traits related to resource use and energy flow were monitored in a tropical forest wildlife community in southeast Cameroon, where hunting activities have escalated in the last decade. Wildlife abundances significantly decreased by 2009, and species richness and functional diversity declined by 2016. This reduction in functional diversity suggests that the wildlife community has been considerably altered, compromising ecological functions, and indicating the start of ecological decay. The study found a significant reduction in keystone species, such as great apes and elephants, suggesting that their decline as a result of hunting is leading to ecological imbalance. The results suggest that, beyond a certain threshold of wildlife decline, wildlife community collapse and ecological decay are likely. Identifying such thresholds can inform sustainable wildlife management and help monitor the health or integrity of the ecosystem, and its ability to provide globally significant ecosystem services, such as carbon sequestration and storage.