The Role of Natural Predators in Wild Horse Ecosystems
Mountain lions are natural predators of wild horses and burros. These apex predators balance ecosystems and could help to regulate wild horse populations. But between hunting tags and government kill programs aimed at protecting livestock, thousands of mountain lions are killed on public lands each year.
Overview
10,000 years ago, the saber-tooth cat Smilodon fatalis was a fearsome predator in what is now the American West. They predated on tapirs and deer, young bison, and horses. Fast-forward to the present, where the modern-day version of these predators, mountain lions (also called cougars or pumas), have made their stake in the American West. Scientists have recently begun to understand the vital role played by top predators in ecosystems and the profound impacts that occur when those predators are wiped out.
According to the Mountain Lion Foundation, “Mountain lions fill an irreplaceable and complex role on the American landscape. They keep deer and elk herds on the move so that they do not overgraze in any particular area. This results in less erosion along riverbanks and increases habitat for other species. Ecosystems with lions are healthier, more sustainable, and contain rich resources, benefiting people and wildlife alike.”
A great example of how apex predators can balance and improve an ecosystem happened in Yellowstone when wolves were reintroduced to the area.
Case Study
Studies have shown that a mature mountain lion can kill and feed off one foal every two weeks. In fact, during a 2004 study on the Pryor Mountain area in Montana, only 1 out of 28 foals survived that year, mostly due to mountain lion predation. After coming across killed juvenile mustangs, or living juveniles with large scrap marks on Nevada’s Virginia Range, Biologist Dr. Meeghan Gray set out to study the cause and began researching mountain lions. After capturing and collaring one of the largest female mountain lions on record, she found that 77% of a mountain lion’s diet consisted of young horses. During the 10-month tracking period, the mountain lion was shown to have killed 20 juvenile horses.
In the Montgomery Pass Wild Horse Territory, mountain lion hunting has not happened in decades, and as such, the wild horse population is considered to be at an ecologically effective level.
In a recent study, University of Nevada, Reno researchers state that mountain lions are a top predator in Nevada for ungulates, including wild horses. It also found that wild horses are an important food source for cougars on par with mule deer.
Of course, not every area in the West where wild horses roam is suitable for these apex predators, or would be able to limit wild horse populations solely on their own. But according to Wildlands Network,
“Some researchers suggest that reestablishing a more complete suite of native carnivores through the reintroduction of gray wolves, in concert with supporting a naturally evolving mountain lion population, would provide the basis for an ecologically and economically sound, long-term solution. This approach would not only help stabilize wild horse populations, but would also greatly contribute to restoring native grasslands, woodlands, and forests.”
A Broken System That Prioritizes Profit Over Wildlife
Unfortunately, every year, Wildlife Services, an agency under the U.S. Department of Agriculture, kills millions of native wild animals mostly to protect livestock interests and other corporate agriculture businesses on our most wild lands. In 2018, agents killed 2.6 million animals, including 375 mountain lions, and hunters (with state and federal permits) killed thousands more.
Eliminating natural predators to protect livestock interests in the same area where wild horses and burros roam is counterproductive to wild horse management.