By Bruno Vander Velde
BOGOR, Indonesia–An innovative new model has mapped the potential sustainability of bushmeat hunting across the Congo Basin, shedding light on where more resilient species exist—and where certain species are at risk of extinction from overhunting.
The importance of bushmeat to the diets of rural people has come into the spotlight in recent months due to the potential links between bushmeat and Ebola virus disease, which has killed thousands of people this year in parts of West Africa.
But when it comes to bushmeat, a more pressing long-term challenge than disease, many scientists say, is the viability of the species being hunted. Overhunting has decimated certain species in areas of the Congo Basin, leading to concerns of “empty forests”—and empty stomachs. Any attempts at evaluating the presence and sustainability of hunting over such a large area have been small and scattered.
In terms of gauging bushmeat sustainability, “until now, we have been hunting a big animal, if I may use that analogy, with a pea-shooter,” said John E. Fa, a professor at Imperial College London and linked to the Center for International Forestry Research’s (CIFOR) Bushmeat Research Initiative, led by Dr. Robert Nasi.
“We needed a bigger gun.”
So Fa and scientists from the University of Málaga and CIFOR created a complex model to assess—and map—the “potential hunting sustainability” for nearly 200 species of mammals. The model does not rely solely on data on species’ typical range—such data is fairly incomplete and fragmented, according to Fa—but instead employs a complex array of variables to determine a species’ geographic “favorability,” that is, where the environmental conditions are most adequate to the thriving of that species.
Their model, detailed in a recently published paper in PLOS One, found distinct “hot spots,” with high levels of mammal diversity, as well as “weak spots”—areas where there are more species vulnerable to overhunting, determined by a combination of biological characteristics of each species and the distribution of these within the different habitats. Armed with such knowledge, policy makers and practitioners could design management rules helping to protect species and the people who rely on them for their nutrition.
Fa spoke recently with Forests News about the paper, the first of several studies that his team is planning to publish on this topic. An edited transcript of his interview follows.
Question: What kinds of species did your study assess the potential hunting sustainability of, and why?
Answer: The study only included mammals. Unfortunately, there isn’t data for other species like birds and reptiles. We know a lot about mammals, but we also know that crocodiles, for example, are very much affected by hunting in this region.
Mammals make up over 90 percent of all bushmeat hunted in Central Africa. It’s a bit of a double-whammy: We have lots of data on mammals, and mammals are also incredibly important in the supply of animal protein to countless numbers of people on the continent.
Q: The study focuses on the “favorability” of species rather than “presence” of a species. Can you tease out the distinction between these two concepts?
A: Favorability modeling is a distribution model that allows you to assess the relationship between the presence of an animal and the environmental conditions that it is in. It is slightly different from what people have been using up to now. The statistical models we have used in our study differ from those commonly used and give us a methodological edge that can allow us to go further in our understanding of hunting sustainability in Africa.
It provides us with an idea of where a species is more likely to survive better than in other areas. So the maps that we generate through each one of these species—almost 200 of them—give you an idea of where each of these species is “best off.” Favorability is another way of saying there’s a good association between environmental variables and the presence of a species.
Q: Your paper describes three kinds of areas with respect to mammalian bushmeat species: “Hot spots,” with high levels of mammalian presence and diversity; “weak spots,” or hot spots that are vulnerable to overhunting; and “strong spots,” areas with high levels of very resilient species. Can you talk about the respective locations of these “spots”?
A: The important thing is, when you look at the map, you can see that the most important areas in the Congo Basin are two areas on either side of the Congo: A chunk of very important areas in Western Africa, around Gabon and Cameroon, and another block of very significant areas in the eastern Congo Basin, that has high diversity but also weak spots and strong spots there. That’s a major finding: The fact that we have these very clear areas that nobody had ever found before. More....