Establishing nature reserves is considered a conservation strategy to preserve 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, Dr. Rhett D. Harrison of Xishuangbanna Tropical Botanical Garden (XTBG) studied the threat of hunting and defaunation in tropical nature reserves.

The study found that a majority of bird and mammal species have either been extirpated or exist at densities well below natural levels of abundance, making the tropical nature reserves almost empty forests. They considered that hunting is the biggest threat to the conservation of biodiversity. The focus of conservation efforts on select, often remote sites fails to address the fundamental causes of the problem.

There is a need to acknowledge the unpalatable but undeniable fact that current tropical conservation efforts are failing. He pointed out that a large proportion of the conservation estate is already empty forest, and with the loss of important symbionts. 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. If the wildlife populations are not well restored, the ecosystems in tropical nature reserves will continue to degrade.

The researcher proposed that a substantial shift toward improving the management and enforcement of tropical protected-area networks is required.

The study entitled “Emptying the Forest: Hunting and the Extirpation of Wildlife from Tropical Nature Reserves” has been published in Bioscience, 16 (11): 919-924, 2011.