Although typically referred to as a generalist species, individual prey specialization and selection have been documented in cougars (Puma concolor). This behaviour has the potential to limit and regulate ungulate dynamics, particularly in cases where ungulates exist in small or isolated populations. Cougars are notoriously difficult to monitor due to their low density, large range-size, and solitary nature. Traditional methods used to quantitatively estimate the diets of these carnivores – including GPS relocation clustering, snow tracking, and scat collection – are often resource limited, labour intensive, and restricted in their temporal resolution. To circumvent these drawbacks, we used C and N stable isotope (SI) analysis to infer prey specialization of 7 cougars in west-central Alberta. We sampled hair, vibrissae, claw-tips, and blood from cougars to assess diet over different timescales related to tissue metabolism and growth period. We related cougar tissue SI values to prey hair values using Bayesian based mixing models (MixSIAR). We then compared SI results to observed diet composition and specialization determined via kill-site analysis for each cougar.
Results/Conclusions
We were unable to resolve unique isotopic prey profiles for members of the Cervidae family, though we could distinguish between bighorn sheep (Ovis canadensis) and Cervidae spp. Mean isotopic determinations of cougar specialization were positively correlated with observed prey composition; however, some cougar tissues were more strongly correlated than others likely due to prey niche overlap, small sample sizes, and limited felid-specific diet-to-tissue discrimination factors. Although restricted in species resolution, our results indicate SI analysis could be a useful low-cost complementary analysis in future large felid diet studies.