Does hunting regulate cougar populations? A test of the compensatory mortality hypothesis

Abstract

Abstract. Many wildlife species are managed based on the compensatory mortality hypothesis, which predicts that harvest mortality (especially adult male mortality) will trigger density-dependent responses in reproduction, survival, and population growth caused via reduced competition for resources. We tested the compensatory mortality hypothesis on two cougar (Puma concolor) populations in Washington, USA (one heavily hunted and one lightly hunted). We estimated population growth, density, survival, and reproduction to determine the effects of hunting on cougar population demography based on data collected from 2002 to 2007. In the heavily hunted population, the total hunting mortality rate (mean 6 SD) was 0.24 6 0.05 (0.35 6 0.08 for males, 0.16 6 0.05 for females). In the lightly hunted population, the total hunting mortality rate was 0.11 6 0.04 (0.16 6 0.06 for males, 0.07 6 0.05 for females). The compensatory mortality hypothesis predicts that higher mortality will result in higher maternity, kitten survival, reproductive success, and lower natural mortality. We found no differences in rates of maternity or natural mortality between study areas, and kitten survival was lower in the heavily hunted population. We rejected the compensatory mortality hypothesis because vital rates did not compensate for hunting mortality. Heavy harvest corresponded with increased immigration, reduced kitten survival, reduced female population growth, and a younger overall age structure. Light harvest corresponded with increased emigration, higher kitten survival, increased female population growth, and an older overall age structure. Managers should not assume the existence of compensatory mortality when developing harvest prescriptions for cougars.

Is anthropogenic cougar mortality compensated by changes in natural mortality in Utah? Insight from long-term studies

“…We could not reject the null hypothesis of additivity in the Monroe population once parameter uncertainty was accounted for, a finding that has been supported by other carnivore studies (Cooley et al, 2009;Creel and Rotella, 2010;Robinson et al, 2014). Indeed, Cooley et al (2009) observed that although immigration compensated for hunting mortalities, they found like us that compensation via other vital rates (e.g.…”

“…the same question by assessing the human-carnivore interaction as a predator-prey relationship (Cooley et al, 2009;Creel and Rotella, 2010;Sparkman et al, 2011;Robinson et al, 2014); yet, only one of these studies has addressed the problem of sampling variance in competing mortality risks (Murray et al, 2010). By adopting a similar approach to that of Murray et al (2010) in cougars, a carnivore with a completely different social structure (i.e.…”

Viability of a small, geographically-isolated population of beluga whale, Delphinapterus leucas: effects of hunting, predation, and mortality events in Cook Inlet, Alaska

“…Specifi cally, a review of multiple studies showed that removal of breeding wolves, Canis lupus, led to decreased wolf packs or to the dissolution of packs, and that pup survival was higher in larger packs and was correlated with the presence of auxiliary nonbreeders (Brainerd et al, 2008). Heavy hunting pressure on cougar populations, Puma concolor, was correlated with increased immigration, reduced kitten survival, and reduced female population growth (Cooley et al, 2009).…”

Trophy Hunting, Conservation, and Rural Development in Zimbabwe: Issues, Options, and Implications

“…Trophy hunting uses a quota system approach that promotes sustainable off-takes by removing a fraction of natural population growth rates, which arguably falls within the compensatory mortality range and has a negligible impact on overall ecology of wildlife species [13,14]. The quota system used in trophy hunting is based on ecological theory, that is, maximum sustainable yield (MSY), set 2 International Journal of Biodiversity in such a way that off-take levels are always below the growth rate of the target species at any given time [11,15,16].…”