Abstract
•Competitive games are used to simulate criminal hunting of protected wildlife.•An experimental test of human behavioral response to devaluation strategies.•Security deters illegal hunting more successfully than devaluation strategies.•Devaluation can exacerbate, rather than mitigate, the illegal hunting of wildlife.
Illegal hunting and trade might be reduced by devaluing the commodities of live animals. However, theory and anecdote suggest that the tactic’s success depends on the proportion devalued and may also generate unintuitive and counter-productive outcomes. Unfortunately, the difficulty of researching criminals limits empirical and experimental tests of theory and practice. We overcame those constraints by designing and conducting a competitive game; simulating criminal hunting of protected wildlife where the proportion of animals devalued across a meta-population increases at a cost to investment in security. We conducted 33 games each with 10 different volunteers from the public visiting five public events (fairs, gala, and carnivals) in different communities of the Wellington metropolitan area, New Zealand. Games confirmed the relative effectiveness of security over devaluation tactics. Even moderate security protected the majority of commodities, but only when devaluation reached extraordinary levels (≥90%) was it protective, and even then only partially. When the risk of hunting is low, reduced rewards were enough to still motivate hunting. Games also revealed that when security and devaluation tactics are mixed across a meta-population, elevated risk caused hunters to revise their valuation of devalued commodities upwards and hunt and harvest them anyway. Counter-intuitively, more valuable devalued commodities were preserved but those of lesser value harvested, then sometimes discarded but at other times their value claimed. And lastly, hunters choose to take greater risks, shifting their activities to adjacent populations where the returns could be greater even though known to be better protected. The survival of wildlife in those populations deteriorated, even as the number of hunters caught increased. In all these ways, our games demonstrated how the addition of devaluation tactics to strategies for protecting wildlife can incentivise and exacerbate, rather than mitigate, the illegal hunting and trade of wildlife, consistent with theory and anecdote.