Wild carnivores are threatened by human activities, particularly by lethal responses to livestock predation. As natural prey populations decline, predation of livestock and consumption of discarded livestock ‘waste’ (carcasses and body parts) should increase. We investigated whether parameters linked to the production of livestock waste affected the likelihood of livestock predation. We interviewed 160 households near Ruaha National Park in Tanzania to obtain information on households, livestock ownership, predation and parameters linked to livestock waste production. Our analysis identified parameters that affected the likelihood of predation on cattle, sheep and goats. When these parameters were controlled for, we found an increased likelihood of cattle predation as waste from diseased and slaughtered cattle increased. Sheep predation was more likely and cattle predation was less likely as sheep deaths from starvation increased. Goat predation was more likely in medium-sized than smaller or larger villages, suggesting a trade-off to predators between the increasing benefit of more livestock waste and the costs of higher human disturbance and diminishing natural prey abundance as village size category increased. Our findings suggest that improved disposal of livestock waste from slaughtered cattle and measures to decrease cattle deaths from disease should reduce predation of highly prized cattle.

Environmental problems in agriculture have proven difficult to address due to the spatial heterogeneity and temporal variability intrinsic to agriculture. Agriculture is largely a struggle against nature; both its sustainability and the prospects for improving environmental performance and farm income simultaneously are thus inherently limited. Agriculture's high degree of variability makes direct regulation inefficient. Subsidies for improving environmental performance can have negative consequences and have proven ineffective in practice, due largely to bureaucratic culture. Pollution taxes should be the most effective and efficient form of policy. Interdisciplinary research is needed to provide models for performance evaluation.