Sport Hunting, Predator Control and Conservation of Large Carnivores

Craig Packer,Gianetta Purchase,Luke Hunter,Megan Strauss,Alexandra Swanson,Lilian Pintea,Hilary S Cooley,David Garshelis,Kristin Nowell,Margaret Kosmala,Guy Balme,Henry Brink,Michael Somers

doi:10.1371/journal.pone.0005941

Abstract

Sport hunting has provided important economic incentives for conserving large predators since the early 1970's, but wildlife managers also face substantial pressure to reduce depredation. Sport hunting is an inherently risky strategy for controlling predators as carnivore populations are difficult to monitor and some species show a propensity for infanticide that is exacerbated by removing adult males. Simulation models predict population declines from even moderate levels of hunting in infanticidal species, and harvest data suggest that African countries and U.S. states with the highest intensity of sport hunting have shown the steepest population declines in African lions and cougars over the past 25 yrs. Similar effects in African leopards may have been masked by mesopredator release owing to declines in sympatric lion populations, whereas there is no evidence of overhunting in non-infanticidal populations of American black bears. Effective conservation of these animals will require new harvest strategies and improved monitoring to counter demands for predator control by livestock producers and local communities.

Highlights

Management agencies typically skew harvests toward males in order to protect adult females
In species with extensive paternal investment such as African lions (Panthera leo), trophy hunting can increase the rate of male replacement to the point of reducing population size unless offtakes are restricted to males old enough to have reared their first cohort of dependent offspring ($5–6 yrs of age) [1,2,3]
Solitary felids have none of the ‘‘safety nets’’ provided by the cooperative cub rearing strategies of African lions [4,5], and Fig. 1ab illustrates the greater vulnerability of solitary species by examining the effects of trophy hunting on a hypothetical population of ‘‘solitary lions’’ while leaving other demographic parameters from ref. [1] unchanged (Supporting Information Table S1, see ref. [6])

Summary

Introduction

Management agencies typically skew harvests toward males in order to protect adult females. Solitary felids have none of the ‘‘safety nets’’ provided by the cooperative cub rearing strategies of African lions [4,5], and Fig. 1ab illustrates the greater vulnerability of solitary species by examining the effects of trophy hunting on a hypothetical population of ‘‘solitary lions’’ while leaving other demographic parameters from ref. Leopards (Panthera pardus) may be more sensitive to sport hunting than solitary lions (with a safe minimum age of 6–7 yrs of age, Fig. 1c), whereas cougar (Felis concolor) males can be safely harvested as young as 4 yrs of age (Fig. 1d). We tested whether infanticidal species are vulnerable to overhunting by focusing on four large carnivore species with sizable markets for sport-hunted trophies, comparing three infanticidal felids (lions, cougars and leopards) to American black bears (Ursus americanus). We used black bears as a control case because males do not kill cubs in order to increase mating opportunities (sexuallyselected infanticide – SSI), so rates of infanticide are not increased by male-biased trophy hunting; among ursids, SSI has been documented in only one population of European brown bears (U. arctos) [7,8,9]

Methods

Results

Conclusion