Carbon Costs and Bushmeat Benefits of Hunting in Tropical Forests

Unsustainable hunting is widespread globally, generating one of the primary threats to tropical vertebrates but providing important revenue for many people. Recent evidence suggests that by removing seed dispersing vertebrates, overhunting can induce shifts in tree species composition that reduce the amount of carbon stored in the forest. I developed a bioeconomic model to assess the conditions under which hunting might lead to the loss of forest carbon, and to compare the revenue lost via carbon erosion to that gained from bushmeat procurement. The potential long-term decline in forest biomass and the uncertain degree of ecological complementarity among frugivore species had the strongest influence on the amount of carbon lost via overhunting. Parameters related to frugivore population dynamics and the economics of the hunting system had relatively little influence. Total revenue in the system was maximized when hunter effort and the opportunity costs of hunting were low, suggesting that limiting hunting effort could maximize income for hunters by avoiding the depletion of both game species and potentially saleable carbon credits. These results highlight that enhanced understanding of long-term carbon responses to hunting in different tropical forests could help increase revenue for forest-dwelling people and contribute to global climate change mitigation efforts.