By Samantha Miller
“There’s no doubt that mountain lion hunting is not needed for broad-scale population control,” said Jim Keen, D.V.M., Ph.D., a former U.S. Department of Agriculture scientist and former faculty member at the University of Nebraska, in a newly published report that surveys on-point scientific literature on the management of mountain lions.
“Selective control of depredating lions provides social and psychological benefits to ranchers and others who come in conflict with lions,” he adds, “but even then, most conflicts can be managed by non-lethal means.”
Earlier this month, Cats Aren’t Trophies (CATs), a political committee organized in Colorado with nearly 100 endorsing organizations, submitted 188,000 petition signatures in support of a statutory initiative for the November statewide ballot.
In Colorado, over the course of a single hunting season, trophy hunters shoot more than 500 lions a year, mainly by using dogs to chase and drive the quarry into a tree. Trophy hunters, many of them with the aid of a professional guide offering a “guaranteed kill,” then shoot the trapped animal. Trophy hunters and commercial trappers also kill up to 2,000 bobcats during a single season.
A Scientific Review of Mountain Lion Hunting and Its Effects examines peer-reviewed research that gives insight into the beneficial role of lions in ecosystems and the groundless claim that trophy hunting does anything but provide a recreational killing opportunity for the participants, who almost exclusively rely on packs of dogs to facilitate the hunt for trophy mounts. Dr. Keen is both a veterinarian and an infectious disease specialist and serves as the director of veterinary sciences for Animal Wellness Action and the Center for a Humane Economy.
“Coloradans can debate the ethics of hunting mountain lions for trophies in the upcoming ballot measure campaign, but they should not be sidetracked by scientifically groundless arguments from its opponents about the supposed necessity of lion killing for trophies,” Dr. Keen added. “Any serious examination of the literature drives the conclusion that mountain lions are self-regulating and will not overpopulate even in the absence of shooting by trophy hunters.”
On the other hand, Dr. Keen observes, “There’s no question that lions do provide population regulation services, limiting high deer and elk densities that reduce impacts on forestry and dangerous auto crashes with the large-bodied cervids. Lions also selectively remove neurologically impaired deer and elk suffering from Chronic Wasting Diseases, a deadly brain-wasting pathogen widespread among Colorado herds.”
For support of this conclusion about lions as self-regulating, Dr. Keen and others point to the California experience. That state has banned any trophy or recreational hunting of mountain lions for 50 years, and populations have been stable there over the decades. In the last three years combined, government agents killed a total of 28 lions total statewide (3 in 2021, 10 in 2022, and 15 in 2023), with most conflicts resolved by non-lethal means.
Dr. Rick Hopkins started studying lions in California in the 1970s, and he notes that California has a stable mountain lion population even though there is no trophy hunting and very limited lethal take of lions for damage control.
“We kill cougars through sport take and control efforts not because hunting has been shown to be an important management tool, but because it is tradition,” notes Rick Hopkins. “To argue that hunting is needed for population management is an overly simplistic argument about natural systems—one that conflicts with both predation theory and evidence.” Dr. Hopkins obtained his PhD in Wildlands Resource Ecology from University of California, Berkeley.
National parks throughout the West — from Rocky Mountain to Glacier to Olympic — also forbid lion hunting, and there are no greater densities of lions there than in any other areas.
The Keen report makes four key conclusions.
There are no recent field-based research reports in the peer-reviewed literature that describe a negative correlation between mountain lion trophy hunting and human-lion conflict reports.
There is little to no evidence that trophy hunting of mountain lions either significantly increases deer and elk hunting opportunities for sportsmen or women or reduces mountain lion conflicts with people, livestock, or pets. Big cats do, however, seem to target highly vulnerable and neurologically impaired deer and elk, playing a meaningful role in suppressing the spread of Chronic Wasting Disease.
Field-based observational research the author examined in multiple Western states concludes that trophy hunting of mountain lions exacerbates and worsens human-lion conflict. The mechanism appears to be that trophy mountain lion hunting destabilizes mountain lion social-, territorial-, and age-sex structures.
Trophy hunters often attempt to target the largest and most dominant males. This alters the age structure of exploited lion populations, creating vacancies in the previously occupied territories and allowing younger and less experienced subadult males to take over territories. Younger males are less experienced at killing traditional prey, such as deer or elk, and they may seek non-traditional prey, creating more conflicts with ranchers or pet owners.
“Sport hunting of mountain lions does nothing to alleviate conflicts between mountain lions and humans,” said Josh Rosenau, mammalogist and director of policy and advocacy for the Mountain Lion Foundation. “In fact, as Dr. Keen shows, peer-reviewed science demonstrates that sport hunting may exacerbate human-lion conflict.” The Mountain Lion Foundation has developed decades of expertise on mountain lion management and protection issues.
Because cats do not have a distinct breeding season, shooting mother cats invariably orphans juvenile and sub-adult cats, who succumb to starvation, dehydration, or predation. In the 2013-24 season, 47 percent of lions shot were females.
For more information, visit the Cats Aren’t Trophies website.