The conservation of plant and animal species in Los Angeles’ urban landscape depends on bold new strategies to address wildlife conservation and habitat fragmentation.
Los Angeles is the second largest city in the U.S. and one of the most iconic cities in the world. Home to 3.9 million residents and the nation’s busiest freeway—the infamous 405—LA is the most population-dense region in the nation. Lesser known to many, the city is also home to at least 1,200 documented native plant and animal species, of which at least 160 are of conservation concern or at risk of extinction. Even amid such a metropolis, flora and fauna can be seen everywhere.
Los Angeles’ centerpiece: the Santa Monica Mountains
Situated in the heart of LA lies one of the city’s most precious assets, the Santa Monica Mountains. The largest intact natural area in the city, the range extends 40 miles east-west from Griffith Park in Los Feliz through the Hollywood Hills to Point Mugu and the Pacific Ocean in Ventura County.
The Santa Monica Mountains are home to much of LA’s open space and biodiversity, including many species of plants and wildlife ranging from mule deer, mountain lion, bobcat, and coyote, to fishes, birds, amphibians, and invertebrates. The Santa Monica Mountains are part of the South Coast Ecoregion, which supports more endemic—and imperiled—plant and animal species than any other ecoregion in the country.
The Santa Monica Mountains also form a significant portion of the Rim of the Valley Corridor. This area surrounding the San Fernando Valley contains important cultural and natural resources such as remnant habitats and open space, habitat linkages, and recreational trails.
It’s an incredible experience to walk the trails of the Santa Monica Mountains and see the beauty of the region juxtaposed with the sprawling city, which is one of the most frequented natural areas in California. Spend enough time there, though, and you will see firsthand the consequences faced by wildlife living in such close proximity to people.
Urban encroachment results in extensive fragmentation; habitat loss for terrestrial, aquatic, and fish species; and exposure to toxins and poisons. Amid the urbanization, river channelization, and large freeways, flora and fauna in the region have become isolated from populations, life-sustaining resources, and habitats in adjacent natural areas and mountain ranges that they rely on for reproduction and survival.
If animals dare to attempt to move or migrate, they must navigate a gauntlet of human-dominated landscapes and busy highways that are difficult to pass and often deadly. Research indicates that many species—including the iconic mountain lions of the region—have become genetically isolated due to this fragmentation and are at risk of local extinction within our lifetime.
Two mountain lions were recently found dead in the Santa Monica Mountains, likely due to rodenticide poisoning. This occurs when rodent poison accumulates through the food web from rodents to predators. Poisoned animals slowly bleed to death leaving them exposed, lethargic, and vulnerable to predators. Predators who ingest the poisoned prey either die from induced hemorrhages or suffer from suppressed immune systems and secondary diseases such as mange. Of the mountain lions tested in the Santa Monica Mountains, 96% have tested positive for rodenticides, with some testing positive at levels high enough to precipitate disease and death.
Fire is also a major concern for the region’s wildlife. The 2018 Woolsey Fire alone burned 40% of the natural areas in the Santa Monica Mountains, leaving behind a vast charred moonscape. The fire was three times larger than any previously recorded fire in the range. Species’ ability to escape such devastation, survive the aftermath, and recolonize are hindered by the existing level of fragmentation and habitat loss in the region.
Overdevelopment, fragmentation, and habitat loss—coupled with other human-caused impacts (e.g., wildlife-vehicle collisions, rodenticide poisoning)—add pressure to an ecosystem already under stress. The cumulative impact of these pressures elevates the need for urgent and bold conservation action in the region.
The future LA-ndscape
Fortunately, the news is not all grim. New efforts are underway to conserve and restore important cultural and natural resources such as remnant habitats, open space, habitat linkages, and recreational trails.
LA’s Wildlife Pilot Study will take place in the Santa Monica Mountains from the Sepulveda Pass to Griffith Park. The project aims to study the region’s important habitat and connectivity areas as well as identifying conservation standards and regulations. As the region recovers from the Woolsey Fire, other researchers will continue to track species’ recovery to identify the toll of the fire and further inform the conservation needs of the region.
Just west of LA, Caltrans and the National Wildlife Federation (NWF) are designing the world’s largest wildlife crossing over Highway 101 at Liberty Canyon in Agoura Hills. Such structures are highly effective at reconnecting fragmented ecosystems and reducing wildlife-vehicle collisions. The need for such structures does not stop in Agoura Hills. The conservation of species in urban landscapes depends upon connecting habitats and garnering support—and momentum for such actions depends upon connecting communities to nature.
The city is at an inflection point between planning and infrastructure development. The traditional paradigms we’ve used to build and develop our landscapes are no longer sustainable or acceptable. New approaches to understanding what it means to live in an urban landscape—and how that landscape interacts with ecosystems—are being embraced, fostered, and expected by communities.
This past October 13-19, 2019 marked the 4th annual Urban Wildlife Week in LA led by NWF and local partners. The event culminated at a festival in Griffith Park to educate the public about the importance of habitat connectivity, wildlife coexistence, and conservation. Urban Wildlife Week was inspired by the desire to conserve the incredible biodiversity of the region and to raise awareness about the unsustainable pressures being exerted on our wildlife species and natural areas.
Working as a community to reduce the impacts of infrastructure development and learning how to coexist with the natural world around us is the new trajectory of the city. LA is well-positioned as a leader in the development and implementation of a more sustainable and connected landscape—and a new path forward into the future.