When rarity fuels species exploitation: Linking consumer demand, hunting effort, and population dynamics with a bioeconomic model

Classifying species by threat status can result in conservation benefits such as increased protection, but can also act as an incentive to hunters responding to increased consumer demand for rare goods. Bioeconomic modeling provides a framework for assessing the conflicting effects of a declaration of rarity on the population size of a hunted species. While the standard (Gordon-Schaefer) model of open-access exploitation predicts that hunting will not result in extinction, this model fails to take account of the response of consumers (demand) and hunters (supply) to changes in perceived rarity. Here we extend this model to explore the scenario where a declaration of rarity directly affects consumer demand and hunter costs. We find that an increase in demand associated with a species' rarity may stimulate hunting which traps the species at a low density, or drives it to extinction. We highlight some 'warning signals' of rarity-fueled exploitation and discuss the potential impact of intervention strategies.