The Roads Less Traveled

Just before dawn and slightly before dusk, animals in the hills surrounding the San Fernando Valley go on the move. They’re crossing under freeways, over them and across surface streets. Sometimes it’s food and water they’re after. Other times, it’s a mate or a new home.

Coyotes, bobcats, mountain lions, grey foxes, mule deer, raccoons and badgers are among the animals that travel from one area to another using so-called wildlife corridors. These paths were carved by the animals and are essential in a world in which open space makes way for modern development.

“Everything has been whitteled down to these,” said Paul Edelman, staff ecologist for the Santa Monica Mountains Conservancy. “It’s by sheer chance that we’re left with these.”

Through most of the corridors were not planned by man, developers must now take them into consideration. Wildlife corridors near the proposed Newhall Ranch project, to be built in the Santa Clarita Valley between the Golden State Freeway and the Ventura County line, are being studied.

Here’s a look at the major corridors that animals use to cross freeways and main roads:

1: Salt Canyon. From the Santa Ynez Mountains in the north to the Santa Susana Mountains to the south via Salt Canyon, by traveling across California 126.

2: San Martinez Grande under-crossing. From private land on the north to the Santa Clara River to the south, by traveling under California 126.

3: San Martinez Chiquito Canyon under-crossing. From private land on the north to the Santa Clara River to the south, by going under California 126.

4: Gavin Canyon under-crossing. From open space in the east to open space in the west, bytraveling under the Golden State Freeway along The Old Road.

5: Los Pinetos under-crossing in the Newhall Pass. From the western extreme of the San Gabriel Mountains through Elsmere Canyon, by going under the Antelope Valley Freeway.

6: Corriganville under-crossing. From the Santa Susana Mountains in the north to the Simi Hills in the south, by traveling under the Simi Valley Freeway.

7: Rocky Peak overpass in the Santa Susana Pass. From Rocky Peak Park in the north to Chatsworth Peak in the south, by walking on bridge that crosses Simi Valley Freeway.

8: Big Tujunga Wash. From Big Tujunga Wash in the north to the Verdugo Mountains in the south, by traveling under Foothill Boulevard and the Foothill Freeway.

9: Liberty Canyon Road under-crossing. From parkland in the north to the backside of a small commercial project on the south, by walking on the dirt shoulder under the Ventura Freeway.

10: Las Virgenes Creek under-crossing. From the proposed Malibu Continental Communities project in the north to a flood control easement that leads to Malibu Creek State Park in the south, by using three parallel cement lined paths.

11: Crummer Canyon. Proposed corridor, either to be a tunnel or a bridge leading from Ahmanson Ranch in the north to conservancy-owned open space to the south.

12: Skirball Center Lane crossing in the Sepulveda Pass. From public parkland on the east to county-owned Mission Canyon on the west, using overpass on the San Diego Freeway.

13: Sepulveda Boulevard under-crossing in the Sepulveda Pass. From conservancy-owned land near the Bel Air Crest project on the east to open space owned by the Getty Museum and various agencies on the west, by traveling under the San Diego Freeway.

14: Mulholland Drive at Benedict Canyon Road. From the Valley side of the canyon to the city side, by crossing Mulholland Drive.

15: Laurel Canyon Boulevard. From Nichols Canyon on the east to city-owned Laurel Canyon Park on the west, crossing Laurel Canyon Boulevard.

16: Mulholland Drive overpass in the Cahuenga Pass. From open space surrounding the Hollywood Bowl to Lake Hollywood and Griffith Park, by using overpass on the Hollywood Freeway.

17: Fern Lane under-crossing. From the San Rafael Hills in the east onto the Verdugo Mountains side of the freeway, by going under the Glendale Freeway.

Tracking the Animals

As part of a special study, 30 coyotes and 20 bobcats have been outfitted in the past year with radio collars--each one transmitting its own radio frequency that can be picked up on a receiver by someone in the field.

Visual images are being captured by 44 cameras that are specially rigged to snap a picture when an animal steps on special plate.

The three-year study--an effort of the National Park Service, UCLA, the University of Massachusetts and the Santa Monica Mountains National Recreation Area--is aimed at documenting animal movement, population density, birthrates and death rates to determine the effects of encroaching development on wildlife.

Among the preliminary findings: the Ventura Freeway is a greater roadblock than originally thought. The team has yet to document a successful crossing by a bobcat and only a few by coyotes.

Traveling Traits

These three carnivores use corridors (in map) to cross freeways and roads. Gray foxes (top photo) hang out in pairs. They have frequently been captured on film by a team of ecologists, but there have been few other sightings by humans. Bobcats (middle) are loners. On the other hand, coyotes (bottom) are social, forming loose family groups and hanging out in packs. These wild animals live in dens when they are breeding, but otherwise are on the move, constantly searching for food and trying to stay alive.

Sources: Santa Monica Mountains Conservancy, National Park Service

Researched by STEPHANIE STASSEL / Los Angeles Times