Trophy Hunting: An Age and Sex Structured Model

Abstract

An age and sex structured matrix population model is developed to simulate population dynamics of a trophy hunted polygynous species. The model is used to project population growth rate and abundance of a trophy hunted ungulate species, Capra falconeri, found in the western regions of Pakistan. The impact of harvest (hunting) the species on population dynamics is simulated to assess whether a trophy-hunting program, targeting mature adult males, is sustainable. In the context of projected growth rate and projected abundance, the program is found to be sustainable for harvest rates as high as ninety percent of the mature adult male population. However, other ecological considerations, such as biased sex-ratios, and deterioration in quality of the gene pool prevent such high harvest rates. In view of the sustainability of the program, different delivery mechanisms (or marketing techniques) for sale of hunting permits are assessed to determine the optimal mechanism. In the presence of complete information this turns out to be perfect price discrimination, with a revenue maximizing quota determined by the price elasticity of demand (PED). That is, a larger quota if PED > 1, and a smaller quota if PED < 1, will maximize revenue. In the more likely scenario of incomplete information however, priority pricing (a form of third degree price discrimination) or second-price sealed bid auctions are found to maximize the seller's expected revenues, as opposed to the existing first-price sealed-bid auction.