Science & Conservation
"The cougar is a keystone species on which one can design landscape-level conservation strategies…as well as an umbrella species, because conservation strategies benefiting cougars also benefit an array of other life forms living in intact ecosystems.” (Logan and Sweanor 2001).
The Cougar Fund was founded to help ensure the conservation and protection of cougars throughout their range in the United States and the rest of the Western Hemisphere. Scientific research has shown us that healthy cougar populations help to maintain healthy landscapes and biodiversity. Humans depend on healthy landscapes and biodiversity for clean water to drink, clean air to breathe, for fertile soil in which to grow our food, for medicines derived from plants and other species, for personal and cultural inspiration, for physical and spiritual renewal, and much more. Indeed, our well-being and prosperity is inextricably linked to the health of natural landscapes, the myriad species that live in them, and the intricate web of interdependent relationships that binds it all together. Conserving healthy and well-connected cougar populations not only helps us fulfill our moral obligation to protect nature but also yields immeasurable benefits to humans.
An excellent and concise overview of the importance and challenges of conserving cougars can be found in Ken Logan and Linda Sweanor’s book, Desert Puma: Conservation of an Enduring Carnivore. This seminal book, the culmination of their ten-years of intensive research on cougars in New Mexico, should be read by anyone interested in cougars and their management. The concluding chapter on conservation is particularly informative. In it they write:
“The cougar’s broad geographic distribution, solitary nature, and presence in some of the most rugged and remote habitats helped it escape the regional extinctions (in the Western U.S.) that befell the other large carnivores. The recovery of the cougar in the West has occurred only during the last three decades, the equivalent of three cougar lifetimes. Not only is the recovery an indication of our management successes, but also of the resiliency of the cougar. Today, cougar populations are “high” relative to our collective memories. What they were historically is conjecture. But cougars today also are facing a completely different world than they would have encountered even 100 years ago. Because of our growing human population, cougar habitats and landscape linkages are continually shrinking. Consequently, the recent increases in cougar populations may not be sustainable. The ecological role of cougars, including their ability to help dampen oscillations in prey populations, structure biological communities, and direct the evolution of their prey are all reasons why cougars should be conserved …. Moreover, they can be used as umbrella species to define minimum areas required to preserve ecologically intact ecosystems … In the long run, if humans are to successfully conserve cougars in self-sustaining populations, then people living in or impacting their wild environments will have to be educated and caring. Furthermore, wildlife managers will require a thorough understanding of the animal and potential methods for achieving success in dealing with short-term problems and long-term conservation goals.”
Scholarly research suggests that a key to successful cougar conservation is the development of widespread and enduring public support for maintaining thriving and ecologically-effective populations of cougars and sufficient habitat for supporting them. Certainly, the bases for our decisions must be informed and supported by rigorous, interdisciplinary scientific inquiry. Yet we appreciate that cougars mean different things to different people, and that cougar management also needs to reflect the broad array of perspectives held towards this wide-ranging, majestic, elusive, and powerful predator. As one wildlife professional has pointed out, “Biology is the foundation of wildlife management, but human values are the reason for it.” Effective cougar conservation will require integrating, or balancing where necessary, into decision making the range of values held by the public towards the species.
Cougars and their Ecosystems
“Cougars…play an important role in ecosystems, perhaps more than any other large carnivore in the Western Hemisphere. This influence stems from the cougar’s extraordinary capability as a predator, its wide geographic distribution in both South and North America, and the broad diversity of habitats that it uses.” Murphy, Ross, and Hornocker. 1999.
Cougars evolved as integral members of the natural environment and play a key role in maintaining the health of ecosystems and biodiversity in a variety of habitats. Conservation biologists consider cougars to be a keystone species, meaning that their ecological influence is far greater than their mere numbers would suggest. In short, cougars have a potent and widespread ecological role even though they live in relatively low densities on the landscape. The source of the cougar’s influence lies in its relationship to its prey, particularly the deer, elk, and other herbivores that constitute its primary sources of food. By preying on deer and elk, for instance, cougars help prevent their populations from becoming larger than their habitat can support. In areas where cougars have been eliminated or driven out, researchers have found landscapes overrun by herbivores that are overgrazing the land. Without the presence of cougars to check their growth, herbivore numbers increase to the point where they run the risk of consuming all the edible vegetation and preventing regrowth. As these plant species disappear, so do those species dependent on them for food, nesting sites, and other uses. The loss of each species in turn severs a strand in the intricate food webs that connect species to one another and to their habitat.
Where cougar populations have been severely reduced, eradicated or otherwise driven out by humans, researchers have found degraded ecosystems and diminished biodiversity. As leading cougar researchers Ken Logan and Linda Sweanor conclude in their book Desert Puma: Evolutionary Ecology and Conservation of an Enduring Carnivore, the cougar is:
“A model keystone species on which to design landscape-level conservation strategies,” because they: “(1) … strongly influence energy flow in ecosystems; (2) they are a potent selective force on prey animals; (3) they modulate prey populations; thus (4) they indirectly affect herbivory on plant communities; (5) they influence competitive interactions between herbivores; and (6) their persisting populations are dependent on expansive wild landscapes.”
Cougars, as Logan and Sweanor point out, are also known as umbrella species this because protecting habitat sufficient to support healthy populations of this wide-ranging animal helps afford protection for the numerous other species that use that habitat.
Research from North and South America has shown that the disappearance of cougars can have profound impacts on the ecosystems that lead to a loss of biodiversity. In the eastern United States the overabundance of white-tailed deer that has negatively impacted vegetation and many species of birds has been found by scientists to be a consequence of the historical elimination of cougars and gray wolves. Researchers working in a rainforest valley in Venezuela that had been flooded for a hydroelectric project found that newly created hilltop islands that were too small to support cougars or jaguars had been overrun by herbivores. The herbivores were rapidly depleting the island’s vegetation and driving out other species dependent on it. Only ten-years after being created by the flood, a first-time visitor would be startled to learn that these now dry, barren islands covered by a dense thicket of thorny plants were once part of a vast rainforest, teeming with animals, plants, and insects. What started with the disappearance of cougars and other top predators had ended with ecological collapse and the disappearance of numerous species.
Although viable cougar populations continue to exist throughout much of the western United States, decades of suppression through predator control and sport hunting are likely keeping them at levels at which they no longer play their crucial ecological roles.
Other evidence that suggests important ecological role of cougars and the consequences of their disappearance comes from research in the western U.S. by Ecologists William Ripple and Bob Beschta. Ripple and Beschta hypothesize that significant landscape changes in Zion National Park, Utah, occurred after cougars abandoned the canyon in the early 1900s due to a marked increase in human visitation. They propose that the disappearance of cougars allowed the local mule deer population to grow unchecked, increasing browsing pressure on vegetation, and reducing the regeneration of cottonwood trees. The loss of cottonwood and other vegetation led to increased bank erosion along the river and a decline in wildlife and plant abundance on the land and in the river. In a similar study of Yosemite National Park, Ripple and Beschta’s research suggests that the apparent abandonment of Yosemite Valley by cougars in the early 1900s due to human activity released mule deer populations which, unchecked, suppressed the regeneration of black oak trees and led to changes in the habitat. These findings add to a body of evidence indicating that the disappearance or eradication of cougars can result in catastrophic ecological changes.
Although viable cougar populations continue to exist throughout much of the western United States, decades of suppression through predator control and sport hunting are likely keeping them at levels at which they no longer play their crucial ecological roles. The Cougar Fund works to conserve cougar populations so that they can continue to play their vital ecological role and therefore provide innumerable benefits to human society.
Threats to Cougars
Habitat loss and overkill, most scientists agree, are the primary threats to the survival of cougar populations. As human populations grow ever larger and spread across the landscape, the amount of habitat available for cougars and other wildlife is shrinking and becoming increasingly fragmented. This loss and fragmentation of cougar habitat is leading to smaller and increasingly isolated cougar populations that are therefore at a higher risk of extinction. At the same time, the number of cougars killed for sport and coming into conflict with domestic animals and humans is rising. Excessive levels of persecution, or “overkill,” increases the risk that cougar populations, especially small ones, will become extinct. Aside from concerns about extinction, conservation biologists also point out that reducing cougar populations below a certain level may disrupt their important ecological role and lead to declines in the health of the natural landscape and biodiversity.
In some regions the threats of habitat loss and persecution are intertwined, such as in the increasingly urbanized landscapes of the western United States. Increasing development in cougar habitat is both reducing the amount of habitat available for cougars and increasing the likelihood of cougars coming into contact with domestic animals and humans, situations that often result in the death of the cougar involved and calls for the further reduction of cougar populations. Development can also force cougars to relocate to areas where they must compete with other cougars for home ranges. Deaths due to automobile-strikes are also becoming more common as cougars try to negotiate a landscape increasingly fragmented by roads. Outside of National Parks and other protected areas, cougars are finding fewer and fewer places to take refuge. Thus even though history has proven cougars to be an adaptable species, it is crucial that we recognize there are limits to their capacity to survive in the face of these mounting pressures and take action to ensure their long-term survival.
At the same time, the number of cougars killed for sport and coming into conflict with domestic animals and humans is rising. Excessive levels of persecution, or “overkill,” increases the risk that cougar populations, especially small ones, will become extinct.
The Cougar Fund believes that the conservation of cougar populations and the management of cougar-human conflicts must be based on sound scientific principles. Sport hunting of cougars is widely assumed and justified as an effective means for reducing cougar-human conflicts. Yet a comprehensive assessment of cougar research and management by thirteen leading cougar researchers and managers concluded that there is no scientific evidence that sport hunting or other predator control efforts reduce the likelihood of cougar preying on livestock or attacking humans. In fact, a 2006 study found that people in states where cougars are hunted experienced similar or even greater number of conflicts, on a per capita or unit area basis, compared to people in California where cougar hunting is prohibited. Moreover, several states with high levels of sport hunting had a higher rate of human attacks per capita than did California. The greatest numbers of cougar attacks have occurred on Vancouver Island, British Columbia, where cougar hunting is allowed. Vancouver Island has reported more than 1.5 times as many attacks than California even though it has only 1/8th the cougar habitat and 1/100th the human population. Sport hunting for cougars is a source of recreation for cougar hunters and a source of revenue for state game agencies and some local communities.
The Cougar Fund believes that decisions about cougar management should serve the common interests of the public, which is the goal of public policy in a democracy, and not the special interests of a few. As public institutions, state wildlife agencies are mandated to conserve cougars and other wildlife as part of the public trust. Yet a considerable percentage of citizens across the western U.S. have expressed both opposition to current policies and strategies and concern that their perspectives are not being included in policy making. That cougar management has become increasingly controversial and the focus of highly politicized and uneducated debate is a sign that the common interest is not being satisfied. Of course, disagreement over cougar management is to be expected, and The Cougar Fund seeks to create opportunities for healthy and constructive deliberation between people with different values and perspectives.
The core problem, however, as some observers of cougar management have concluded, is not that people disagree over cougar management but that our current decision making process is failing to clarify and secure the common interest. We believe that the common interest in cougar conservation includes the conservation of ecologically-effective populations of cougars across their range and habitat adequate for sustaining them.
It is our position that the membership of wildlife commissions empowered with making decisions about wildlife management should better reflect the electorate. At present, hunting and agricultural interests are disproportionately represented. In addition, responsibility for funding wildlife conservation should be shared among all citizens and not come primarily from the sale of hunting licenses and taxes on firearms. Our success or failure in conserving cougars and their habitat is ultimately contingent on improving how we make decisions so that it is more participatory and creates policies that reflect our commonly held interests.