UCLA

Biodiversity across the world is in decline due to population increases as well as urban development. Subsequently, fragmentations of the landscape and habitat loss are occurring. Globally, only twenty-one biodiversity hotspots remain, and nowhere is the risk more severe than in Southern California. In countering these threats, it has become necessary to connect all available open lands in Southern California to create a network for wildlife movement. Such an interconnected set of reserves will allow natural ecological processes to continue and thrive, as they have for centuries. Thus, researchers in the field identified the Santa Monica – Sierra Madre Connection as the highest priority linkages to conserve, which would provide miles of roaming ground to a wide variety of animals, ranging from shrews to mountain lions. Mammals, especially mountain lions, require a large area for hunting and to thrive genetically. However, this once-contiguous mountain range stretching from Santa Monica to Sierra Madre was severed in the early 1970s by the construction of the US-101 Freeway, dividing the habitat range into isolated habitat fragments and severely restricting movement for many wildlife species, including mountain lions, bobcats, gray foxes, coyotes, and mule deer, between the two mountain ranges. For mountain lions in particular, this restriction has led to increased inbreeding, territorial fighting, and very low genetic diversity. Research conducted by the National Park Service since 2002 has demonstrated that because of a fragmented landscape, mountain lions could face extinction in the Santa Monica Mountains within fifty years, with a median of fifteen years. Therefore, researchers analyzed several locations and investigated probable alternatives and recommended the development of a vegetated bridge over US-101, near Liberty Canyon Road, in the City of Agoura Hills, which would both provide the best location in the region for improving connectivity and serve the broadest range of species. Once built, this bridge would be the largest wildlife crossing of its kind in the world and the first to attempt a large-scale intervention for wildlife in an urban area with over twenty million people—and over a roadway carrying over three hundred thousand vehicles per day. This project will set a model worldwide for urban wildlife conservation and help inform future efforts. It has renewed the urgency to keep our wildlife from going extinct because of urban development and demonstrates that animals and humans can coexist.