Pumas, People, And Safe Highway Passage: The Case For Rewilding

In Memoriam: P-22

In late 2022, disaster struck the City of Los Angeles. It wasn’t pandemic-related or a disastrous earthquake, or even a traffic jam on the 405. Instead, the city mourned the death of one of its most popular celebrities. A hometown hero, P-22¹ was far from the average well-groomed starlet. Elusive yet beautiful, perhaps it was his feline-like features or his intimidating stature. He resided in the Hollywood Hills and could be occasionally spotted roaming Griffith Park, a neighborhood he’d moved to from his previous home in the Santa Monica Mountains.

However, instead of racking up credits on the silver screen, P-22 was known for gracing the doorbell cameras and backyard security footage of Angelenos, occasionally picking off a small dog or two. In 2012, a mountain lion was caught on a motion-sensing camera² in Griffith Park. Nicknamed P-22, experts concluded that the wayward cat had journeyed from the Santa Monica Mountains, crossing through the 405 and 101 freeways in the process. To make an unlikely journey even more unfathomable, the 101 freeway forms a nearly impassable barrier for the puma population of the Santa Monica Mountains, cutting off their already-dwindling gene pool and leading to inbreeding and genetic anomalies.

Despite the odds, P-22 lived out his days in the park, presumably isolated from the rest of the region’s mountain lion population. The celebrity cat was ultimately euthanized after he was found suffering from severe injuries from a probable vehicle collision. The face of California mountain lion conservation and a poster child for the construction of the world’s biggest wildlife bridge³, the death of the beloved city-dwelling mountain lion offers an opportunity to consider the rift in the relationship between urbanization and natural ecosystems. As metropolitan areas continue to swell in size and density, so do the number of animals and natural ecosystems that unintentionally become our neighbors. Yet we continue to expand, typically without a second thought, and most often at the expense of native flora and fauna.

What Is Rewilding?

Despite P-22’s tragic end, it isn’t the fault of the migrant mountain lion or the anonymous driver who hit him. Rather, his unconventional life and death were a result of urbanization⁴ and provides a chance to consider the importance of intentionally-designed urban spaces that take into account native species.

Dissatisfied with simply halting the sprawling effects of human development, the process of rewilding⁵ aims to turn back the clock, reconstructing the natural and native ecosystems of the past. Rooted in conservation biology, rewilding efforts typically refer to large-scale biological and ecological restoration. Strategies vary in practice from restoring native species, re-introducing keystone species and apex predators, and restoring patterns of natural abundance.

Rewilding can take countless forms. Common projects include: restoring wetlands and forests, bringing back grazing animals, reducing fishing pressure, restoring kelp and filter feeders, removing dams, reconnecting rivers with their floodplains, setting aside large reserves, and reintroducing species entirely to revamp the food webs within local ecosystems. A subset of traditional conservation, biologists aim to achieve a self-regulating ecosystem with pre-human species populations and levels of biodiversity. Originally envisioned as a continent-wide effort that centered around the “three Cs”⁶—protecting wilderness cores, building wildlife corridors, and recovering large carnivores—the movement has been reinterpreted and rescaled into conservation strategies at all levels.

Step one requires determining the history, politics, and ownership of a chunk of land. This starts with identifying potentially wild core areas⁷, determining habitats and ecosystems present, what species call the area home, and assessing overall ecosystem health. This analysis must also look at whether there are pollutants or poisons present, what species have been driven from the ecosystem (and why), and whether there are habitable wildlife corridors that connect the area with other cores. Whilst criteria for a portion of land eligible for rewilding can vary depending on many situational factors, it’s also crucial to identify whether and how humans have altered the landscape.

‍

An Extension Of Conservation: Components Of Rewilding

Rewilding takes traditional conservation one step further by considering the ecological impacts of existing modifications. These modifications consider the landscape dynamics such as visitors to the area and how the resources are currently being used, to design an effective and individualized rewilding process.

In some instances, rewilding can be a relatively non-intensive process. A plot of land may be set on the trajectory to replenish ecosystem health through simple actions. Legal protection, eliminating exhaustive hunting, fishing, or harvesting, removing physical barriers like fences, roads, and dams, and will allow the area to naturally redevelop into a wild space on its own. However, the choices and decisions can get more complex the more existing human development is involved. More intensive rewilding efforts may look like ecological engineering, physical reconstruction, and reintroducing extirpated wildlife species that play a major role in ecosystem function—generally referred to as keystone species.

Keystone species often come in the form of apex predators, who sit at the top of the food chain.  Reincorporating these species can theoretically reverse the effects of what’s described as a “trophic cascade,”⁸ or altered food web interactions due to a lack of maintenance by top predators. Bringing large mammals back into ecosystems requires more land. Keystone species can also engineer ecosystems. The Eurasian beaver⁹ was reintroduced into areas of the UK suffering from extreme rainfall in early 2021, and the species helped to reduce water flow in local waterways, decreasing the effects of flooding.

When implemented correctly, rewilding can offer numerous ecosystem benefits, the most prominent being the reclamation of land by the species that originally called it home. Ecosystems have the potential to be restored at significant scales and may create new socioeconomic opportunities while naturally combating climate change. Some argue that establishing open natural spaces can also help wildlife adapt to climate change naturally—although this human interference is an oxymoron within itself, giving species the space they need to adapt to changes in the climate could give them a better chance at survival.

Perhaps the most famous example of rewilding can be found in Yellowstone National Park.¹¹ Wolves were entirely eradicated from the park in the 1920s as part of an effort to remove all predators. No sooner than the last pack had disappeared did the balance of the ecosystem crumble—elk populations skyrocketed, overgrazing on native fauna. Without plants serving to harness erosional processes, riverbanks eroded, collapsing beaver dams and the rivers expanded. In the late nineties, the wolves were gradually reintroduced and the equilibration of the ecosystem was immediately evident. Wolf populations within the park are still on the rise, and the initiative is lauded as one of the most successful rewilding efforts to date.

Rewilding urban spaces can also create beneficial byproducts¹² for humans. More green space has been scientifically proven to boost human health and well-being and opens up possibilities for the diversification of economic opportunities, including environmental entrepreneurial ventures and nature-based enterprises, and other jobs and services that could be created in conjunction with restoring the land to its native state. The potential benefits of rewilding are contingent upon rigorous scientific study, ecosystem and food web analysis, and simply weighing the pros and cons. When these integral components aren’t adequately evaluated, rewilding efforts can create serious consequences for the native environment.

What Does Responsible Rewilding Look Like In California?

Despite its shortcomings, many conservationists are drawn to the proactivity and solutionism that rewilding offers. Although rewilding can take nearly infinite forms, the International Union for the Conservation of Nature offers several recommendations to guide cooperative and holistic initiatives. The IUCN suggests prioritizing local engagement and community support, anticipating potential climate change effects, research guided by scientific principles and similar healthy ecosystems, and constructing adaptive plans with the acknowledgment that ecosystems are dynamic systems, amongst several other guiding principles. The implementation of nature-based solutions requires a cross-societal approach, relying on the knowledge of science, the power of government, and the engagement of local communities.

While our engorged freeways and scattered cityscapes suggest otherwise, the power of imagination isn’t needed to envision rewilding initiatives in heavily-developed California. From the nearly-completed Wallis Annenberg Wildlife Corridor across the 101 freeway, to a hefty land acquisition in the Tehachapi Mountains, which connects to several other cores of conservation preserves, California is still just beginning to discover the accommodations and changes that can be made to integrate urban areas into the native ecosystems around them.