Literature Review

Barua, M., S. A. Bhagwat, and S. Jadhav. 2013. The hidden dimensions of human–wildlife conflict: Health impacts, opportunity and transaction costs. Biological Conservation 157:309–316.

Study Summary

Focusing mainly on Asia and Africa, researchers examined the hidden and secondary costs of human-wildlife conflict. It is well recognized in areas of high conflict with species such as elephants, tigers, lions, and leopards that injury and death are direct negative costs of human-wildlife conflict. However, the secondary and often long-ranging costs of human-wildlife conflict are less understood.

Researchers found that when a death in a family occurs, often the male head of household and main breadwinner, their duties fall on the shoulders of the women and children within the family. This can lead to poor mental health and lack of school attendance for children, which impacts future job opportunities for those children.

For rural ranchers, trips to the city to obtain compensation for livestock loss can be a larger burden than the loss of livestock due to time lost not managing their ranch and the money spent on travel. Ranchers staying up at night to guard livestock experience sleep deprivation, which has lasting health complications.

As wildlife managers, we often focus only on the primary consequences of human-wildlife conflict, such as the loss of livestock and crops. However, in areas of ongoing human-wildlife conflict, managers should work with experts such as social scientists, psychologists, or social workers to understand and manage the hidden physical and mental strain of human-wildlife conflict on ranchers and farmers.

Brown, D. E., and M. R. Conover. 2008. How people should respond when encountering a large carnivore: opinions of wildlife professionals. Human-Wildlife Interactions 2:194–199.

Study Summary

This 2008 study surveyed 53 wildlife professionals across the U.S. and Canada to gather opinions on responding to encounters with large carnivores, such as black bears, grizzly bears, mountain lions, and wolves. Most agreed that increasing distance—by slowly backing away, often while alerting the animal—was best for nonaggressive encounters.

Responses to attacks varied by species: all recommended fighting back against mountain lion or wolf attacks; for grizzly bears, around half advised fighting if predatory but being passive if defensive, while many suggested passivity regardless. Climbing a tree was appropriate for grizzly bears but not black bears or mountain lions. All endorsed bear pepper spray as effective. The study urges local wildlife managers to develop species-specific guidelines tailored to regional conditions.

Collinge, M. 2008. Relative risks of predation on livestock posed by individual wolves, black bears, mountain lions, and coyotes in Idaho. Proceedings of the Vertebrate Pest Conference 23.

Study Summary

Performed in Idaho, the researchers looked at a very simple metric to understand relative risk to livestock loss based on population estimates for wolves, black bears, mountain lions, and coyotes. The paper evaluated the loss rate based on the tracked numbers of sheep and cattle losses. Sheep losses had been tracked from 2005 to 2007, while cattle losses had only been tracked in 2005.

Using population estimates of each predator species, the researchers combined the number of losses from sheep and cattle for 2005 (the only combined year) and then divided the total number of losses by the estimated population of each predator to obtain a per capita rate of depredation.

While the paper notes this is an incredibly simple methodology, and can create an overgeneralization of how much loss per predator species is occurring, it also gives researchers a holistic view of overall losses, which can help managers understand which species may be most at fault for losses as compared to perceived loss.

The authors discuss that while losses due to wolves may not affect all ranchers equally, in the areas where ranchers and wolves overlap, they may have a disproportionate amount of losses due to wolves than due to other predators.

Dellinger, J. A., K. D. Gustafson, D. J. Gammons, H. B. Ernest, and S. G. Torres. 2020. Minimum habitat thresholds required for conserving mountain lion genetic diversity. Ecology and Evolution 10:10687–10696.

Study Summary

This study by Dellinger et al. explores how the amount and protection status of habitat affect the genetic health of mountain lions in California, using data from 263 GPS-collared mountain lions across the state, collected over several years.

The findings suggest that preserving large, connected habitats is key to supporting healthy mountain lion populations, emphasizing the role of protected areas in reducing threats like habitat fragmentation, which isolates populations, reduces gene flow, and increases inbreeding risk.

The research highlights the importance of conservation efforts to safeguard mountain lions and their ecosystems. As an umbrella species, mountain lions benefit other wildlife when habitats are connected, supporting species with similar needs. The study also reveals that several of California’s nine mountain lion populations, including Santa Cruz, Santa Monica, and Santa Ana, lack sufficient land space to preserve genetic diversity, putting them at risk for inbreeding due to isolation.

It underscores the urgency of enhancing habitat connectivity and protection to mitigate these risks and ensure their survival, offering insights for future management. This provides a foundation for strategies to address tensions between human development and wildlife needs.

Hudenko, H. A. W. 2014. Understanding human-wildlife interactions in U.S. National Parks: The role of emotion in human behaviors that foster habituation and food conditioning in wildlife. Dissertation, Cornell University.

Study Summary

This dissertation examines how wildlife and humans habituate to each other in U.S. national parks, exploring how human habituation contributes to wildlife conflicts. It distinguishes food conditioning, where animals learn to associate humans with food due to provisioning, from habituation, the loss of an animal’s fear response to humans after repeated, non-threatening encounters.

Through qualitative interviews at Acadia National Park, the study found that park goers’ emotions and prior wildlife experiences influenced their visiting behavior, often leading to actions like approaching or feeding wildlife, despite awareness of park guidelines. These emotionally driven behaviors, shaped by context-specific beliefs, can foster wildlife habituation and food conditioning, increasing risks to safety and conservation.

The paper proposes management strategies, emphasizing emotion-based messaging, a “conservation recreation” framework, and consistent education to improve communication with park goers.

Murphy, K. M. 1983. Relationships between a mountain lion population and hunting pressure in western Montana. Master’s thesis, University of Montana, Missoula.

Study Summary

While not conducted in California, this study examined a heavily hunted mountain lion population over several winters from 1979 to 1982, focusing on changes in population structure. Approximately 32% of the population was removed annually through regulated hunting. Despite this high harvest rate, the population structure remained stable, even compared to lightly hunted populations in surrounding areas.

The authors attribute this stability to an overabundant deer population, which supported greater hunting success for mountain lions. Recruitment was balanced by both internal population growth and immigration from dispersing juveniles in neighboring populations.

The study highlights that hunter success, facilitated by road access, favorable hunting conditions, and abundant prey, influences mountain lion population stability. In areas like El Dorado County, where deer populations are reportedly in severe decline, this paper suggests that a higher deer population could support a more stable lion population.

Packard, J. M., T. K. Ruth, and R. Skiles. 1991. Behavior of high risk mountain lions in Big Bend National Park, Texas. USDI National Park Service.

Study Summary

Between 1986 and 1991, Big Bend National Park recorded 15 incidents involving mountain lions. To address human safety concerns, researchers radio-collared individual mountain lions to investigate whether specific behaviors increased the likelihood of human-lion conflicts. The study hypothesized that young male lions, due to inexperience and nutritional stress during their dispersal phase, were more prone to risky interactions with humans.

The tracked lions displayed varied behaviors: some consistently avoided humans, while others frequently approached and remained active near people, showing no fear but also no aggression.

The study found that the risk of injury during lion encounters was largely determined by human actions. Incidents often involved unattended children or pets, whereas encounters without harm typically occurred when humans acted assertively to deter lions. The authors recommend proactive management, including educating visitors on hiking safely in lion habitat, preventing attacks, and responding appropriately during encounters, to reduce the likelihood of negative incidents.

Parsons, M. A., B. E. George, and J. K. Young. 2024. Evaluating the efficacy of aversive conditioning of mountain lions with hounds. Canadian Wildlife Biology & Management 13(2):126–137.

Study Summary

The authors conducted tests to explore whether lions could be trained through aversive conditioning with hounds to flee when hearing human voices. Lions were captured and fitted with GPS collars, with some designated as treatment lions and the rest as control lions. Treatment lions were hazed with hounds after human voices were played via a radio carried by approaching researchers, while control lions were not hazed despite similar approaches.

Researchers equipped themselves with speakers and played talk radio to mimic human voices at a consistent rate and volume. Treatment lions were located using their GPS collars, and researchers approached them slowly. After reaching a set distance and exposing them to talk radio, trained hounds were released to haze the lions for a fixed duration. Lions were tracked to determine if they fled the area after hearing human voices alone, as well as how far and how long they fled.

After hazing with hounds, lions were tracked to assess how far and how long they fled.

The results showed that lions hazed with dogs after exposure to human voices increasingly fled sooner with each additional researcher approach. This means that after just a few sessions, lions hearing human voices (via the researchers’ radio) linked the negative experience of being hazed by hounds with those sounds, fleeing sooner and farther. Lions not hazed with hounds showed the opposite response, becoming more habituated to human voices and less likely to flee the area.

Pooley, S., S. Bhatia, and A. Vasava. 2021. Rethinking the study of human–wildlife coexistence. Conservation Biology 35:784–793.

Study Summary

This paper discusses the processes by which we should re-evaluate how the science of human-wildlife conflict is researched and understood. Most studies of human-wildlife conflict around the world, with a particular focus on carnivores, examine the negative effects and specific conflicts between people and wildlife, such as being attacked by a tiger or Nile crocodile.

This paper offers definitions of coexistence as being not just the absence of conflict, but also the acceptance of both humans and wildlife by each other on the landscape they share.

Other topics discussed include social science points for the wildlife biologist, how to handle cultural differences when interviewing residents, and how researchers should self-examine their own biases and differences with residents before interviewing. Suggestions include planting oneself within the culture for several weeks, if not months, before actual interviewing or following residents around using open-ended interview structures to first learn what the right questions to ask are.

Wildlife researchers combining elements of social sciences should work with social scientists and cultural experts within regions of interest to learn not just what questions to ask but how to ask them.

Raithel, J. D., M. J. Reynolds-Hogland, D. N. Koons, P. C. Carr, and L. M. Aubry. 2017. Recreational harvest and incident-response management reduce human–carnivore conflicts in an anthropogenic landscape. Journal of Applied Ecology 54:1552–1562.

Study Summary

Analyzing 33 years of black bear data (1981–2014) and human-bear incidents (2001–2013) in New Jersey, this study assessed whether recreational harvest and lethal management reduced human-bear conflicts. It identified problem bears (e.g., causing property damage or nuisance behaviors) and found they were significantly more likely to be harvested or lethally managed than non-problem bears.

Nuisance incidents, such as garbage visits, consistently declined in years following harvests, particularly when paired with educational outreach on reducing attractants starting in 2008. This integrated approach—recreational harvest, lethal management, and education—effectively lowered nuisance behaviors, supporting coexistence in a human-dominated landscape.

Randolph, J. F., J. K. Young, D. C. Stoner, and D. K. Garcelon. 2024. Impacts of management practices on habitat selection during juvenile mountain lion dispersal. Ecology and Evolution 14:e70097.

Study Summary

This study tracked juvenile mountain lions leaving their mother’s home range to establish their own territories, comparing populations in a protected area (California) with those in a non-protected area (Nevada). Using GPS-collared juvenile mountain lions, researchers examined how these young lions, during their dispersal phase, navigate landscapes.

Specifically, the study compared a California population, where mountain lions are a specially protected species, to a Nevada population subject to regulated hunting.

Findings revealed that both populations used major trails, off-highway vehicle (OHV) roads, and other dirt roads or cuts as dispersal “highways,” consistent with prior research showing lions utilize trails and fire access roads for rapid movement. However, the populations differed in residential areas: protected California lions moved more slowly, with meandering patterns, while Nevada lions, in non-protected areas, moved quickly and linearly through such areas.

The authors suggested that these movement differences likely stem from varying risks of human conflict, with California’s protected lions facing less risk of harm compared to Nevada’s hunted population.

Volski, L., A. McInturff, K. M. Gaynor, V. Yovovich, and J. S. Brashares. 2021. Social effectiveness and human-wildlife conflict: linking the ecological effectiveness and social acceptability of livestock protection tools. Frontiers in Conservation Science 2:682210.

Study Summary

This 2021 study tested FoxLights to protect sheep from coyote depredation, assessing their effectiveness and livestock owners’ perceptions. Researchers randomly assigned and rotated FoxLight placements in pastures to prevent predator habituation, finding no difference in depredation rates between treated and untreated areas.

Pre- and post-intervention interviews showed livestock owners, unaware of these results, perceived fewer losses with FoxLights and valued them as an extra tool, boosting confidence in protecting livestock. Despite learning FoxLights were empirically ineffective, owners disagreed, believing their hands-on experience could improve FoxLight use, and planned to continue using them. The study highlights the contrast between scientific ineffectiveness and positive social acceptability.

Weaver, R. A., and L. Sitton. 1978. Changing status of mountain lion in California and livestock depredation problems. Proceedings of the Vertebrate Pest Conference 8:214–219.

Study Summary

In 1971, a bill signed by then-Governor Ronald Reagan granted mountain lions temporary protection through a hunting moratorium. This allowed the California Department of Fish and Game (now the Department of Fish and Wildlife) to collect data on mountain lion populations to inform management strategies and reverse population declines across California. This paper, one of several written during the moratorium, focuses on mountain lion depredation on livestock.

The study analyzed livestock depredation records from 1971 to 1977, supplemented by interviews with Fish and Game personnel, livestock owners, and private wildlife specialists.

The findings examined losses to identify patterns, including depredation locations, livestock species involved, the age and sex of lions, and the depredation permit process. The paper then proposed recommendations and highlighted limitations of mountain lion management within the depredation system.

Specifically, it suggested improvements that resemble today’s depredation system, such as deploying a wildlife or conflict specialist to the scene promptly, improving training to identify the predator responsible, and documenting details like livestock species, breed, number, ages, and other factors involved in depredation incidents.

The paper notes that, at the time, Nevada’s use of trained lion hunters through a sport hunting system effectively reduced depredation conflicts, lowering the number of depredating lions taken annually on permits from 100 to 10. While the paper does not explicitly recommend sport hunting as a management tool for reducing localized livestock depredation conflicts, its final statement alludes to Nevada’s approach, suggesting that sport hunting reduced the number of lions taken on depredation permits.

However, it emphasizes that California’s special protection status for mountain lions precludes this as a management option.

Winter, S. Y., D. H. Van Vuren, T. W. Vickers, and J. A. Dellinger. 2024. Response of mountain lions to hazing: does exposure to dogs result in displacement? Proceedings of the Vertebrate Pest Conference 31. Paper No. 14.

Study Summary

Conducted in California and drawing on data collected over several years, the authors explored whether mountain lions exhibit behavioral differences after capture using two methods: cage trapping versus hound pursuit. The authors were testing to understand if two capture methods drastically changed the behavior of lions after use. The study analyzed mountain lions fitted with radio collars after being captured.

Data was categorized based on capture method—cage traps or hounds—and lions were tracked to determine how long it took them to return to their capture sites.

Results indicated that lions, regardless of capture method, generally returned to within a set distance of their capture site in a similar timeframe. However, lions captured with hounds showed a slight delay in returning compared to those caught in cage traps. This delay was not statistically significant, though the trend was noted.

The research aimed to assess whether hound pursuit versus cage trapping causes notable behavioral changes in mountain lions. Understanding these differences could help researchers evaluate how hounding might affect study outcomes, particularly if lions alter their territory or range use after pursuit, potentially skewing GPS collar data.