Challenges Facing Pumas at the Urban Edge

Pumas, also known as mountain lions or cougars, are incredibly adaptable creatures with the widest distribution of any terrestrial mammal in the Americas, second only to humans. They inhabit forests of Northern Canada down to the Patagonian steppe. These large carnivores play a crucial role in maintaining the health of ecosystems. Despite their significance, puma populations are declining across their range(1) , with potentially serious implications for both the environment and human health.

The Ecological Role of Pumas

Pumas are keystone predators, meaning they have significant direct and indirect impacts on other species, and their environment(2). By preying primarily on hoofed-animals like deer, pumas help control these populations, preventing overgrazing and reducing the risk of deer-vehicle collisions, which can be dangerous for humans and wildlife. Additionally, deer are known carriers of tick-borne diseases such as Lyme disease, so by keeping deer populations in check, pumas indirectly help manage the spread of these diseases. Further, when pumas kill prey, the carcasses they leave behind provide vital food sources for other scavengers, including birds of prey, mammals, and insects(3).

Threats from Habitat Loss

Despite their ecological importance, pumas face numerous threats, primarily due to human activities. In the United States, urban expansion and habitat fragmentation have forced pumas into closer proximity with human settlements. As a result, they must increasingly navigate urban edge habitats. Historically, pumas were found across the country, but now their range is mostly limited to the western states. Roads, cities, and agricultural developments have fragmented their habitats, making it necessary for pumas to move through urban and residential areas. Pumas are elusive and they avoid contact with humans. However, the growing overlap of shared spaces increases the likelihood of human-wildlife conflicts, as pumas may opportunistically prey on domestic animals like pets, hobby animals and livestock.

Disease Risks

The overlap between pumas, domestic animals, and humans also raises concerns about zoonotic disease transmission. Zoonoses can compromise wild felid health, while also affecting public human health and that of domestic animals. Felids are definitive hosts of a parasite called Toxoplasmosis, which is widespread among domestic cats.Toxoplasmosis is a threat to public health and is of interest because of its potential to alter host behavior (risky behavior) and because of the risk of transmission between wildlife, pets, and people. This risk may also be greater at the urban edge, where domestic cats (especially unsupervised or feral ones) are more prevalent and where they overlap with wild cats like pumas or bobcats.

Because pumas can carry potentially lethal parasites, viruses and bacteria, this poses health risks to humans. Zoonoses and spillover risk are particularly concerning in areas where pumas, domestic cats, and humans frequently interact.

Pumas in California

California, the most populous state in the USA, is home to a vital population of pumas.In most of California, pumas are the only apex predator left so their presence is crucial to a healthy ecosystem. In the San Francisco Bay Area, pumas often live at the edge of urban and wilderness areas. Despite the region's extensive network of protected areas, human development surrounds much of this land. Millions of people visit these open spaces each year, increasing the potential for human-puma encounters. Educating the public on how to safely coexist with pumas is crucial to preventing negative encounters.

Beginning in 2020, the Central Coast and southern California puma subpopulations entered an extinction vortex(4) due to early signs of inbreeding and reduced genetic diversity, and are now listed as candidate species under the California EndangeredSpecies Act (CESA).

Since 1990 the sport hunting of pumas has been prohibited in the state, however depredation permits are issued when pets or livestock are taken by pumas, and are more rarely issued for threats to public safety. The CESA status will provide stricter protections(5) . This is in contrast to other states such as Montana, Wyoming, Texas,Idaho, Colorado, and others where hunting pumas for sport is legal.

Conservation Efforts: The Bay Area Puma Project

To address the challenges facing pumas along California’s central coast, the Bay AreaPuma Project (BAPP) was established in 2007 by the Felidae Conservation Fund. This is the first long-term puma project in the region, using research, technology, and community engagement to ensure the persistence of pumas in the greater SanFrancisco Bay Area. BAPP collects data on puma presence, behavior, movement, and health using non-invasive methods like camera traps, fecal surveys and hair snares. A current focus of BAPP research is tracking zoonoses and spillover risks. We use a One-Health(6) approach to quantify risks to human health and wildlife health. Public awareness campaigns are also a key part of BAPP's work, helping to educate people about pumas and reduce unnecessary fears.

Most of the San Francisco Bay Area is puma habitat so BAPP educates local communities on how to respond should they encounter a puma in the wild. Despite the extremely low chance of a puma encounter, many people have a disproportionate fear towards large carnivores(7). Thus, BAPP engages with local communities through in-person and virtual outreach, putting into perspective the level of risk of a puma attack, which is less than 1 in 6 million. This is far less common than being attacked by a dog 8or being in an accident due to a distracted driver(9).

Coexistence Strategies

To coexist with pumas, it's important to follow certain guidelines. If you encounter a puma while hiking, do not run or turn your back. Instead, stand your ground, make noise, and try to appear larger to scare the animal away. Hike during daylight hours to avoid encountering wildlife that is more active at dawn and dusk.

Misconceptions and Education

There are many misconceptions about pumas, such as the belief that their numbers are higher than they actually are(10). Advances in technology, like personal security cameras, have made it easier to spot pumas, but multiple sightings in a neighborhood often involve the same individual, not different pumas. Understanding that adult pumas are solitary and have large home ranges (100 square km) can help reduce unnecessary fears.

The Future of Pumas

Thanks to BAPP’s ongoing research and conservation efforts, and other research entities, our understanding of puma ecology and behavior has significantly improved.This growing body of knowledge reveals insights about pumas at the urban edge(11-13). Despite widespread human presence, pumas are largely successful at avoiding people.There are few (<3) public safety incidents in the state each year and pumas in California have largely managed to avoid conflicts. However, continued urban development poses ongoing challenges. By supporting research and community engagement, we can help ensure that pumas and humans can coexist peacefully in shared landscapes.

 

References

1. Nielsen, C., Thompson, D., Kelly, M. &amp; Lopez-Gonzalez, C.A. 2015. Puma concolor (errataversion published in 2016). The IUCN Red List of Threatened Species 2015:e.T18868A97216466. https://dx.doi.org/10.2305/IUCN.UK.2015-4.RLTS.T18868A50663436.en.

2. LaBarge, LR, Evans, MJ., Miller, JR, Cannataro, G, Hunt, C and Elbroch, LM, 2022. Pumas Puma concolor as ecological brokers: a review of their biotic relationships. Mammal Review, 52:360-376.

3. Allen ML, Elbroch LM, Wilmers CC and Wittmer HU. 2015. The comparative effects of large carnivores on the acquisition of carrion by scavengers. The American Naturalist. 185: 822-33.

4. Gustafson KD, Gagne RB, Vickers TW, Riley SP, Wilmers CC, Bleich VC, Pierce BM, KenyonM, Drazenovich TL, Sikich JA, and Boyce WM. 2019. Genetic source–sink dynamics among naturally structured and anthropogenically fragmented puma populations. ConservationGenetics 20:215-27.

5. California Department of Fish and Wildlife (CDFW). 2024. Mountain lions in California.https://wildlife.ca.gov/Conservation/Mammals/Mountain-Lion

6. Center for Disease Control (CDC)l. 2024. About One Health. https://www.cdc.gov/one-health/about/index.html

7 Johansson, M. and Karlsson, J. 2011. Subjective experience of fear and the cognitive interpretation of large carnivores. Human Dimensions of Wildlife 16:15-29.

8. Bieber, C. 2 Oct 2023. Dog attack statistics by breed. Forbes.https://www.forbes.com/advisor/legal/dog-attack-statistics-breed/

9. Bieber, C. 23 Feb 2023. Distracted driving statistics &amp; facts. Forbes.https://www.forbes.com/advisor/legal/auto-accident/distracted-driving-statistics/

10. Sahagan, L. Jan 4 2023. LA Times.https://www.latimes.com/environment/story/2024-01-07/california-has-fewer-mountain-lions-than-previously-estimated

11. Coon, C.A., Nichols, B.C., McDonald, Z. and Stoner, D.C., 2019. Effects of land-use change and prey abundance on the body condition of an obligate carnivore at the wildland-urban interface. Landscape and urban planning, 192: 103648.

12. Coon, C.A., Mahoney, P.J., Edelblutte, E., McDonald, Z. and Stoner, D.C., 2020. Predictors ofpuma occupancy indicate prey vulnerability is more important than prey availability in a highly fragmented landscape. Wildlife Biology 2020: 1-12.

13. Stoner, DC, McDonald, Z and Coon, CA. 2023. Stepping stones to extirpation: Puma patch occupancy thresholds in an urban‐wildland matrix. Ecology and Evolution, 13: e10381.