Lions, Bylaws, and Conservation Metrics

African lions are a significant threat to pastoralists, triggering both retaliatory and nonretaliatory killings that represent a high-profile example of human-wildlife conflict. In the present article, we report on a grassroots campaign to reduce such conflict by shifting agropastoralists' attitudes toward lion killing and the central role of bylaws in its apparent success. Insofar as all of East Africa's principal protected areas still harboring lions are surrounded by pastoralist populations, the vast majority of which persecute lions, this novel strategy is of considerable wide-scale and practical significance. We report on an estimated 59%-69% reduction in the number of lions killed since the implementation of bylaws and use our experiences to highlight the need for fresh dialog among project managers, conservation organizations, and their funders in crafting appropriate conservation success metrics. In the context of human-wildlife conflict, changes in peoples' norms and attitudes are of greater significance over the long term than simplistic tabulations of the number of individuals saved.