A University of Alberta study tracking 80 collared cougars in west central Alberta revealed that humans caused 29 of 37 recorded deaths between 2016 and 2021. The research, published in PLOS One, identifies hunting as the primary driver of mortality for these apex predators.
Why 29 of 37 cougar deaths were human-caused
The data collected by the University of Alberta indicates a stark disparity between natural and anthropogenic mortality. out of 37 documented deaths among the 80 collared animals, humans were responsible for the vast majority. According to the report published in PLOS One, the leading cause of death was harvest, which accounted for 16 of the fatalities . Other human-driven causes included eight deaths from traps, two from vehicle collisions, two resulting from human-wildlife conflict, and one authorized removal by a private landowner.
This high rate of human-induced mortality highlights a significant vulnerability for the species.. While natural deaths occur through disease, infanticide, or inter-species aggression, the study suggests that human intervention is currently the dominant pressure on the population in the studied region.
How linear features and roads near Whitecourt increase risk
The research focused on a forested region south of Whitecourt, north of Sundre,and west of Rocky Mountain House. Researchers found that the risk to cougars was not necessarily driven by the overall density of development, but rather by specific "linear features"—such as roads and trails—that provide hunters with easier access to the wilderness. The report notes that the rate at which cougars crossed these linear features was a strong predictor of their mortality.
Interestingly, the study found that proximity to forest edges did not significantly increase risk,which the authors attribute to the use of hunting hounds. Because hounds track scents rather than relying on visual sightings from the edge of the woods, the cougars' traditional camouflage and edge-avoidance behaviors provided little protection against determined pursuit.
The 64 per cent male harvest rate and survival parity
One of the more nuanced findings in the University of Alberta study concerns the gender of the animals being hunted. The data shows that harvest accounted for 64 per cent of male mortalities compared to 35 per cent for females. This reflects a common trend in North American hunting, where there is often a propensity for sex-selective harvest targeting males.
However, as PLOS One reported, this difference in harvest proportion did not translate into a statistically significant difference in the overall survival rates between genders. This suggests that while males are hunted more frequently,other factors may balance the survival equation, or the sample size may have been too small to detect a definitive sex-based survival gap.
The ecological cascade of losing Alberta's apex predators
The loss of cougars in west central Alberta is not merely a matter of species count but a threat to regional biodiversity. As apex carnivores, cougars regulate herbivore populations; when these predators vanish, it can trigger a "cascade" effect that alters the local vegetation, bird populations (avifauna), and the behavior of smaller carnivores through intraguild competition.
This study arrives at a time when North American conservationists are still working to restore large carnivore populations that were decimated in the early 20th century. Ensuring the viability of the Alberta cougar population is essential for maintaining the functional health of the forested ecosystems in the Whitecourt and Sundre corridors.
The missing data on male cougar populations
Despite the breadth of the five-year study, several gaps remain. The researchers explicitly noted that the limited sample size, particularly regarding male cougars, may have reduced the statistical power to detect specific differences in harvest mortality risk. it remains unclear exactly why the survival rates remained similar between genders despite the higher percentage of males being harvested.
Furthermore, the study suggests that future management strategies need more granular data to identify exactly when and where each sex is most vulnerable. Without a higher volume of sampled males, Alberta wildlife managers may be operating on an incomplete understanding of the population's demographic stability.
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