Utah’s Cougar Study: A Lethal Program Without Rigorous Science 

In December, Utah wildlife officials discussed a proposal that would dramatically increase the intentional killing of mountain lions in six regions of the state.

The proposal seeks to determine whether lethally eliminating large numbers of cougars will increase mule deer populations. 

Mountain Lion Foundation is deeply concerned about this proposal because it relies on lethal removal as a management tool. Decades of research across the West show that habitat quality, climate, and migration corridors are the primary drivers of deer numbers, not how many cougars are killed. Utah’s proposal leans on lethal removal despite this body of science and without clear evidence that killing more cougars will achieve its stated goals. We oppose this effort on fundamental principles: wildlife management should be science-based and precautionary, especially when populations are already declining and likelihood of success is uncertain. We are following this issue closely and urging the public to voice their concerns. 

Statements from a series of recent public meetings, raise serious concerns. 

What Utah Officials Said — In Their Own Words 

During the public meetings, official confirmed: 

• The project would run for at least three years, with the possibility of extension 
• Cougars are “very difficult to count,” and precise population estimates are uncertain 
• Unreported mortality, including killing without a tag, is difficult to monitor. 

Why This Matters 

This project does not appear to meet basic scientific standards and lacks several of the fundamental elements required for credible evaluation. 

There are no articulated thresholds that would trigger a pause or reevaluation if cougar populations decline further. There are no defined metrics for what would constitute success or failure. And while deer response is the primary focus, there is no plan to monitor broader ecosystem impacts, including cougar social disruption or increased conflict. Without these components, the state cannot reliably determine whether the intervention is helping, harming, or simply shifting problems elsewhere. 

The project is also supported by private funding from sporting organizations whose missions prioritize increased ungulate numbers. While private funding does not automatically invalidate research, predator management is a politically charged arena, which makes independent oversight, transparent evaluation, and clearly defined methods especially important, yet these safeguards appear limited here. 

Compounding these concerns is Utah’s acknowledgment that cougar populations are already declining and difficult to estimate with precision. Implementing a high-magnitude, open-ended removal program under such uncertainty introduces substantial population risk without demonstrated likelihood of benefit. 

What Science Tells Us 

Decades of peer-reviewed research across the West show that intensive predator removal rarely delivers sustained or landscape-scale recovery of prey populations. Instead, it often destabilizes predator populations, leading to younger, transient animals, increased conflict, and little long-term benefit for deer. Studies that do show short-term gains for prey typically involve narrowly targeted, time-limited actions, not broad, open-ended culling across multiple management units. 

In most systems, deer populations are driven primarily by habitat quality, drought, winter severity, and migration connectivity, not predator abundance alone. When these underlying factors limit deer numbers, reducing predator populations offers little measurable benefit and can divert attention from the real drivers of decline. 

The scientific consensus is clear: removing large numbers of cougars without strong justification, clear objectives, and rigorous evaluation is unlikely to achieve the state’s stated goals and risks causing ecological harm that is difficult to reverse. 

Why MLF Is Paying Attention 

Mountain lions are already under escalating pressure across much of the West. Given acknowledged population decline and uncertainty, lethal management proposals like this are unjustified, unsupported by evidence, and risk irreversible ecological harm. For MLF, these concerns are not abstract, Utah’s approach directly affects the long-term viability of local cougar populations and the landscapes they help sustain. 

The proposed study does not include baseline data, defined safeguards, or clear limits on harm, especially when the burden of uncertainty is borne almost entirely by an apex predator with little margin for error. 

Mountain Lion Foundation believes wildlife management must be grounded in rigorous science, transparency, and a clear commitment to long-term ecological health. That responsibility requires us to scrutinize proposals like this, elevate public-record facts, and ensure the risks to mountain lions and the ecosystems they shape are fully understood by policy-makers and the public before irreversible choices are made. 

What You Can Do: Utah Action Alert & Ways to Help – *Utah Residents Only*

Public voices matter—especially when wildlife decisions carry long-term consequences. 

1. Submit a public comment to Utah wildlife officials 

Ask decision-makers to ensure any action affecting mountain lions is guided by sound science and clear safeguards. 

Submit comments here: https://wildlife.utah.gov/contact – *Utah Residents Only*

How to write your comment 

• Be respectful and concise 

• Focus on science, transparency, and precaution 

• Ask for baseline data, success criteria, and stopping rules 

• Encourage investment in habitat, migration corridors, and coexistence, not predator removal 

Sample language you may copy or adapt: 

I oppose the proposed cougar removal project and urge Utah wildlife officials to apply the precautionary principle. When population estimates are uncertain and trends indicate decline, a large-scale removal program cannot be credibly characterized as a scientific test. Such actions require clear objectives, measurable outcomes, and defined limits on harm, none have been presented. 

Research across the West shows that broad predator culls rarely deliver sustained gains for deer, while habitat quality, climate, and migration routes are far more influential. I respectfully ask the agency to prioritize transparent, science-based management and invest in habitat, connectivity, and coexistence strategies over unsupported large-scale predator removal. 

2. Stay informed as this moves forward 

MLF is tracking this proposal and will share updates, meeting notices, and future opportunities to engage. 

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3. Support science-based advocacy 

Your support helps MLF analyze proposals, elevate public-record facts, and advocate for responsible wildlife management in Utah and across the West. 

Mountain lions are already under pressure. Thoughtful, science-based public engagement can help ensure wildlife policy reflects evidence—not assumptions.