Thursday, September 3, 2015

California freeway wildlife corridor is feasible, study says


Mountain lions and other animals would be able to cross a busy Southern California freeway and find new homes if the state adopts a proposal to build a long-planned wildlife bridge, according to a new study.

The landscaped animal overpass on State Route 101 north of Los Angeles would cost up to $38 million, according to Caltrans research released Thursday by the Mountains Recreation and Conservation Authority.

The 165-foot-wide, 200-foot-long corridor would allow big cats and other wildlife to roam between the Santa Monica Mountains, which are hemmed in by freeways and suburban development, and less constrained wilderness areas to the north.

Experts say dispersing mountain lions is critical for preventing inbreeding but at least a dozen have been killed by traffic in the area since 2002. Three mountain lion kittens born last year in the nearby Malibu Springs area were inbred.

State and federal legislators have endorsed a wildlife corridor in Liberty Canyon near Agoura Hills.

"A secure pathway also is essential to protect motorists, who could be killed or injured by collisions with animals," said state Sen. Fran Pavley, who lives near the proposed overpass.

A young male puma was struck and killed by a car on the freeway two years ago. The animal crossed eight lanes of roadway but couldn't jump a 10-foot-high retaining wall topped with chain-link fencing.

Building the nation's largest wildlife overpass would be ambitious, said Seth Riley, a wildlife ecologist with the Santa Monica Mountains National Recreation Area, a unit of the National Park Service. At the proposed site, the highway has 10 lanes of pavement, including exit lanes.

"I don't know anywhere where people have tried to put such a large wildlife crossing over such a busy highway in such an urban landscape," Riley, who has led the mountain lion study, told the Los Angeles Times.

The overpass would feature drought-tolerant vegetation placed so that it helps funnel wildlife across. Hikers, mountain bikers and equestrians would also be able to use the bridge, Riley said.

Proponents said they plan to seek most of the money for the corridor from public coffers.

Scientists long ago identified Liberty Canyon as the optimal location to build a wildlife passage because of the large swaths of protected public land on either side of the freeway. The lions live in a patchwork of local, state and federal parkland that stretches westward from Los Angeles into Ventura County.

State transportation officials will prepare of an environmental document, to be funded by a $1 million grant from the State Coastal Conservancy. Public hearings will be held through 2017.

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