More than 18% of tropical rainforests are now covered by totally protected areas. If these were well protected, we could feel reasonably confident that current conservation strategies might succeed in preserving a substantial proportion of tropical biodiversity. However, in most parts of the tropics, poachers enter and leave reserves with impunity. On the basis of reports from the hunting literature, it seems likely that a majority of tropical nature reserves may already be considered empty forests—meaning that all bird and mammal species larger than approximately two kilograms—barring a few hunting-tolerant species—have either been extirpated or exist at densities well below natural levels of abundance. The disruption of ecological functions caused by the loss of symbionts further compromises the capacity of these reserves to conserve biodiversity over the long term. A substantial shift toward improving the management and enforcement of tropical protected-area networks is required.