Protected areas reduce poaching but not overall anthropogenic mortality of North American mammals

Abstract

Protected areas are established for diverse conservation strategies, but their effectiveness for conserving species varies widely. We compiled studies that used telemetry to determine cause-specific mortality of North American mammals and compared mortality sources of animals monitored in areas classified as protected by the International Union for Conservation of Nature and non-protected areas. Our dataset consisted of 358 studies which monitored the fates of 28,925 individuals and documented 9348 mortalities of known cause across 66 mammalian species. Although anthropogenic mortality was found to be higher in protected areas, we did not find evidence that protected area status was associated with that difference. However, poaching was 75% lower in protected areas. Within protected areas, we found no evidence that number of years since protection nor IUCN category of protection influenced any mortality source, but proportion of anthropogenic mortality on average decreased by 4% with each additional 50 km2 in protected area size. Species body mass was an important factor determining susceptibility to harvest mortality and anthropogenic mortality overall. Protected areas in North America were associated with reduced poaching mortality of mammals, but the ecological importance of this reduction is likely influenced by population- and species-specific factors.