Deforestation and defaunation threaten tropical forest integrity. Human communities in the tropics rely on forest resources to meet their livelihood needs, but are disparaged for practicing slash and burn agriculture and bushmeat hunting. Conservationists therefore question whether the development aspirations and semi-subsistence livelihoods of rural tropical communities are compatible with tropical forest conservation.
To better understand the role of semi-subsistence communities in deforestation and defaunation in the Brazilian Amazon, we conducted interdisciplinary research at community, landscape and regional scales. At the regional scale, we used Geographic Information Systems and a georeferenced dataset of >600,000 rural households to analyse the patterns and drivers of deforestation and inferred hunting adjacent to 45 Amazonian hinterland rivers. At the landscape and community scales, we conducted fieldwork in agricultural mosaics and forest areas controlled by 63 semi-subsistence communities in the Médio Juruá and Uatumã regions of Brazilian Amazonia. We deployed 383 camera traps, 157 quantitative interviews and 164 Global Positioning System units. We sought to quantify and explicate the 1) livelihood costs incurred through the raiding of staple crops by terrestrial forest vertebrates, 2) degree of depletion that communities exert on the assemblage of forest vertebrates and 3) spatial behaviour of hunting dogs and their masters during simulated hunts.
Our results indicate that at the regional scale, fluvial accessibility and transport infrastructure modulated the drivers, spatial distribution and amount of anthropogenic forest disturbance. In accordance with other research, we found that roads were associated with substantial anthropogenic disturbance adjacent to otherwise inaccessible rivers. At the landscape scale semi-subsistence farmers lost 8% of their staple crop annually to crop raiders and invested significant resources to suppress crop raiders, and to avoid losses an order of magnitude higher. Crop raiding was heightened in sparsely settled areas, compounding the economic hardship faced by communities disadvantaged by isolation from towns. A select few harvest-sensitive species were repelled or depleted by human communities. Aggregate species biomass was depressed near towns rather than communities. Hunting depletion was predicated on species traits, with large-bodied large-group-living species worst impacted. At the community scale, hunting dogs travelled ~13% further than their masters. Urban hunters travelled significantly further than rural hunters. Hunting dogs were recognised to have deleterious impacts on wildlife, but were commonly used to defend against crop raiders.
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