Bushmeat Exploitation in Tropical Forests: an Intercontinental Comparison

Abstract

We calculated extraction and production rates of bushmeat species in two main tropical, moist-forest regions, the Amazon and Congo basins. Extraction was estimated from the average number of animals consumed per person per year from anthropological studies that reported animal kills brought into settlements in the regions. We calculated extraction rates ( kg / km 2 /year) for 57 and 31 mammalian taxa in the Congo and Amazon, respectively. We then examined the sustainability of these extraction rates by basin and by taxa, using extraction-to-production ( E:P) mass-balance equations. Production (tonnes/year) was calculated as the product of rmax (the intrinsic rate of natural increase), mammal biomass, and total area of forest in each region. Species exploitation rates at specific body masses were significantly greater in the Congo than in the Amazon. The E :P ratio for the Congo was 2.4, 30 times the Amazon's ratio of 0.081. Thus, Congo Basin mammals must annually produce approximately 93% of their body mass to balance current extraction rates, whereas Amazonian mammals must produce only 4% of their body mass. We calculated sustainability levels derived from Robinson and Redford's harvest model for each taxa. On a basin-wide level, 60% and none of the mammal taxa in the Congo and Amazon basins, respectively, were exploited unsustainably. To evaluate the effect of error on the estimates of E :P, we conducted a sensitivity analysis, which suggests that the mass-balance was most sensitive to error in standing stock but that our results are robust. We estimated that over 5 million tons of wild mammal meat feed millions in Neotropical (0.15 million) and Afrotropical (4.9 million) forests annually. Our Congo basin estimates are four times higher than those calculated for the region by other workers, and we conclude that the current situation of bushmeat extraction in African rain forests is more precarious than previously thought.