In the closing years of the twentieth century, reports of ape populations in decline caused increasing alarm among conservationists. Not everyone was convinced at first, because broad trends were being extrapolated from patchy data. Many of the reports were anecdotal, and dealt with the fate of individual apes rather than populations; long-term research sites, however, yielded relatively accurate figures over time. Eventually, more and more eyewitness accounts from researchers, conservation field-workers, and investigative journalists drew the same conclusion: our closest relatives in the animal kingdom were facing extinction in a matter of decades unless the causes of their decline were addressed.

The causes were, and still are, human activities. Most of these – hunting, logging, agriculture, and warfare – have been practiced for millennia at self-evidently sustainable levels. The difference today is one of scale – especially when the activities are driven by international commerce and demand from the developed world for resources such as timber and minerals from ape habitats. Even natural threats such as disease are being exacerbated by the impact of the modern world on the apes' habitat. If these pressures continue unchecked, local extinctions will increase, leading to total extinction in the wild within our lifetime.

Attention was drawn in the 1990s to the rise of the commercial bushmeat trade in Africa, linked to the expansion of logging concessions into previously inaccessible forests, especially in the Congo basin (Redmond,1989; Pearce and Ammann, 1995). Bushmeat – the meat of wild animals – varies from caterpillars to elephants.