A new study reveals that mountain lions, also known as cougars or pumas, are not only competing with wolves for prey and territory, but also actively hunting and killing them. The researchers found that wolves have a greater impact on mountain lion populations than human hunting and prey availability, and that mountain lions are responding by ambushing and killing wolves, especially their young.
Why are Mountain Lions Hunting Wolves? A Longstanding Rivalry
Mountain lions and wolves are both large carnivores that occupy similar habitats and feed on similar prey, such as elk, deer, and moose. In the past, these two predators coexisted across much of North America, but their populations declined due to habitat loss, persecution, and extermination campaigns. By the 1920s, wolves were eradicated from most of their former range in the lower 48 states, while mountain lions survived in isolated pockets.
In 1995, the U.S. Fish and Wildlife Service and biologists from Yellowstone National Park reintroduced gray wolves to the park, restoring a key component of the ecosystem. The reintroduction also created an opportunity for scientists to study how wolves interact with other species, including mountain lions.
Previous studies suggested that in places where mountain lions and wolves compete, wolves usually come out on top by stealing the lions’ kills or changing where the cats hunt. But wildlife biologists weren’t sure just how detrimental wolves could be to mountain lion populations.
A New Study Sheds Light on the Wolf-Lion Conflict
A study published in November 2020 in the journal Proceedings of the Royal Society B provided the first evidence that when the two species overlap, wolves have a greater effect on mountain lion populations than hunting by humans and the availability of prey. The researchers analyzed data gathered on 147 mountain lions living in a study site in Wyoming’s Teton Range over 15 years. They found that the mountain lion population dropped by 48 percent during that period, and that wolves were responsible for most of the decline.
The study revealed that wolves affect mountain lions in two ways: by starving out adults and killing kittens. Wolves reduce the amount of prey available for mountain lions, forcing them to hunt more often and expend more energy. This leads to lower body condition and survival rates for adult mountain lions.
Wolves also prey on mountain lion kittens, which are vulnerable to attack when their mothers leave them to hunt. The researchers documented several cases of wolves killing kittens, sometimes wiping out entire litters.
The study also showed that mountain lions are not passive victims of wolf predation. They fight back by ambushing and killing wolves, especially when they encounter them near their dens or kills. The researchers found evidence of mountain lions killing at least nine wolves in the study area, mostly pups or yearlings. They suggest that this behavior is a way for mountain lions to reduce wolf numbers and protect their own offspring.
Implications for Wildlife Management and Conservation
The findings of the study have important implications for wildlife management and conservation. They suggest that wildlife managers should consider the effects of wolves on mountain lion populations when setting hunting quotas or reintroducing wolves to new areas. They also indicate that mountain lions may play a role in regulating wolf populations and preventing them from becoming too abundant or dominant.
The study also highlights the complexity and dynamism of predator interactions in nature. It shows that mountain lions and wolves are not only competitors, but also predators and prey of each other, depending on the situation. It reveals that these two species have a longstanding rivalry that dates back to their evolutionary history, and that they are constantly adapting to each other’s presence and behavior.
The study also demonstrates the value of long-term research and monitoring of wildlife populations. It provides a rare insight into the ecological relationships between two iconic carnivores in North America, and contributes to our understanding of how they shape their environment and each other.
