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12/12/2006
Christopher Papouchis
Conservation Biologist
Executive Summary
In recent years, humans have killed more mountain lions in the American West than at any other time in the past century — greatly exceeding even those years when mountain lions were the target of bounties and government eradication efforts (Figure 1).
From 1997 to 2004 alone, according to records obtained by the Mountain Lion Foundation from state wildlife agencies, nearly 30,000 mountain lions were killed in 11 western states, an average of more than 3,600 each year and an increase of nearly 400 percent since 1970.
The record levels of exploitation in the American West have caused concern among some conservation scientists, particularly in light of a 2002 decision by the World Conservation Union (IUCN), which monitors the status of the world’s species through the IUCN Red List of threatened species, to reclassify mountain lions from a species of Least Concern to Near Threatened because of “a declining trend due to persecution and degradation of its habitat and prey base” (Cat Specialist Group 2002).
Figure 1 . Reported human-caused mountain lion mortality in 11 western U.S. states, 1902-2000 (Torres et al. 2004)
Large carnivorous mammals—the big cats, canids and bears—are considered a crucial element in the race to conserve biodiversity because of their role in maintaining ecosystem health and integrity (Terborgh et al. 1999, Ray et al. 2005). According to Ray et al. (2005), “keeping large carnivores is a measure of how we are doing in the battle to save the planet’s biodiversity.”
In the western United States, the mountain lion is the only remaining large carnivore with viable populations throughout the region (Logan and Sweanor 2001). Consequently, our ability to conserve mountain lions serves as a powerful metric in determining whether we will be successful in conserving biodiversity in in the American West.
State wildlife agencies and commissions have, however, placed little emphasis on conserving mountain lions and continue to manage the species primarily as a resource for sport hunters and as potential sources of conflict with human interests.
It had been widely assumed that mountain lion populations have been increasing throughout the American West (e.g., Riley and Malecki 2001), and that the increasing numbers of mountain lions being killed were having little effect on the status of lion populations. However, since 2003, wildlife officials from four western states have concluded that mountain lion populations in these states have declined in recent years.
Moreover, in 2005, thirteen leading mountain lion scientists and managers cautioned that “Wildlife managers cannot assume that these unprecedented removal levels, especially when combined with the historically high levels of habitat loss and fragmentation that are occurring, have no affect on cougar numbers” (Cougar Management Guidelines Working Group 2005).
Because the primary mission of the Mountain Lion Foundation is to ensur e the long-term survival of mountain lions across their historic range, we wanted to develop a more comprehensive understanding of the extent, causes and distribution of human-caused mountain lion mortality in the American West. This report is intended to inform and encourage scientific and public discourse on how mountain lions are managed and conserved in the United States.
Based on our review of mountain lion mortality records provided by wildlife agencies from 11 western U.S. states for the years 1997 to 2004 (when comprehensive data were available for all mountain lion management units), the major findings of this report are:
In total, humans reported killing 29,387 mountain lions over this 8-year period. On average, 3,673 mountain lions were reported killed each year. 56 % of all human-caused mountain lion mortalities in the American West occurred in the four states of Idaho, Montana, Utah and Colorado. The states which reported the highest number of kills did not have the most suitable habitat for mountain lions. Female mountain lions, which make up the reproductive base of lion populations, comprised approximately 43 % of all the mountain lions killed. The primary justifications for killing mountain lions were:
85 % due to sport hunting 10 % in response to real or perceived conflicts with livestock and other domestic animals 2 % in response to real or perceived concerns over public safety 3 % due to other reasons including road kill, incidental killing, poaching, etc.
Geographic areas with the largest concentrations of kills, defined as mortality hotspots, were:
The northern Rocky Mountains (northern Idaho, western Montana and eastern Washington). The northern Utah mountains Utah’s High Plateau
The record levels of mountain lions killed in the American West by humans in recent years warrant concern for at least two reasons. First, excessive levels of human caused mortality, termed overkill by scientists, has been identified as one of the primary threats to the long-term viability of mountain lions (Logan and Sweanor 2001).
Overkill increases the vulnerability of mountain lion populations to extinction, particularly populations that are small and isolated (Beier 1993, Logan and Sweanor 2001). Intensive and sustained overkill can even destabilize mountain lion populations spread over large regions, known as metapopulations (Logan and Sweanor 2001).
Although conservation scientists may view declines in mountain lion populations with concern, wildlife managers may consider declines the inevitable consequence or even a goal of management (Mace and Hudson 1999).
In fact, high levels of exploitation by humans have been implicated in the declines of mountain lion populations in Utah and Montana and a metapopulation spreading across northern Idaho, eastern Washington and southern British Columbia (Beausoleil et al. 2003, DeSimone, Montana Fish, Wildlife and Parks, personal communication, Utah Division of Wildlife Resources 2005, Lambert et al. 2006).
The second, and more far reaching, reason for concern is the potential negative effects that the intensive and sustained killing of mountain lions may be having on ecosystem health. There is a growing body of scientific research that mountain lions play a key ecological role and that their loss can negatively impact the health of the natural landscape and eventually lead to the extinction of many other species (Terborgh et al. 2001; Ripple and Beschta 2006). Unfortunately, there is a disturbing lack of research aimed at understanding the short term and cumulative effects of exploitation on mountain lion populations, or on ecosystem health.
Effectively conserving self-sustaining and ecologically effective populations of mountain lions in the American West will require actively addressing issues related to exploitation and habitat loss.
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Photo Courtesy of Robert Chaponot
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Focused research to assess the effects of heavy and sustained removals of mountain lions on mountain lion populations and ecosystem health is imperative. More specifically, wildlife agencies and commissions must change their focus from a single-species, utilitarian approach to an ecosystem management approach that considers mountain lions in their ecological context rather than simply as resources for hunters or problems for ranchers, landowners and the general public.
Critically, we must pursue strategies for conservation and management that satisfy the common good—such as maintaining ecological health, conserving biodiversity, and representing the full array of human values towards this species—rather than merely satisfying the needs of special interests.
To this end, the Mountain Lion Foundation makes the following recommendations:
Manage mountain lions in the context of their important ecological role in maintaining and restoring ecosystem health. Base management policies and approaches in the principles of conservation biology (Torres et al. 2004). Scientifically demonstrate that current management practices are maintaining sustainable and ecologically effective populations of mountain lions. Create protected areas and linkages for mountain lions to promote the long-term viability of mountain lion populations. Standardize recording and compilation of mountain lion mortalities so that reporting is consistent within and across states. Standardize criteria and protocols for the issuance of depredation permits and public safety removals of mountain lions so that these are consistent within and across states. Support and initiate research to determine when and where mountain lions play ecologically significant roles and what densities of mountain lions are needed to generate these effects (Ray et al. 2005), and how exploitation of mountain lion populations affects the species’ ecological role. Implement the following management principles and other recommendations of the Cougar Management Guidelines (CMGWG 2005: 8-10), which include:
“A large-landscape approach, on the order of thousands of square kilometers of well-connected habitat with thriving natural prey populations, is necessary for healthy, self-sustaining cougar populations.” “Given uncertainties about basic demographic parameters [of mountain lion populations], responses of populations to management prescriptions or hunter selectivity, temporal and spatial variation, and understanding that cougar habitat is changing, cougar management should adopt an adaptive management approach.”
Adaptive management is “A type of natural resource management in which decisions are made as part of an ongoing science-based process. Adaptive management involves testing, monitoring, and evaluating applied strategies, and incorporating new knowledge into management approaches that are based on scientific findings and the needs of society. Results are used to modify management policy, strategies, and practices” (water.usgs.gov/owq/cleanwater/ufp/glossary.html)
“Cougar management should reflect the full array of human values and input from all stakeholders.” “In light of the diversity of stakeholders and human values, funding for cougar research, management, and conservation should not be derived solely from hunting-related programs.”
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