COUGAR P-12 EVIDENCE THAT WILDLIFE CORRIDORS WORK

Liberty Canyon Interchange on the eight-lane Ventura (101) Freeway. Four-lane underpass is visible in center left. Hill on right is national Park Service Land. Critical choke point is to the left of the underpass. PHOTO BY DAVE BROWN

Conservationists once thought it was enough to preserve a few pieces of unspoiled habitat, but biologists are now telling us that isolated patches of protected habitat do not have enough genetic diversity to maintain healthy populations of wildlife, especially apex predators such as cougars. Without habitat linkages or wildlife corridors, inbreeding could cause such animals to decline and eventually disappear.

By the 1990's urban sprawl and a network of busy freeways and concrete channels had carved much of the original natural habitat of the Los Angeles region into isolated fragments and blocked almost all of the few remaining habitat linkages that could have connected those fragments.

In the 1990's the Los Angeles Times ran a series of articles describing the loss of wildlife corridors and genetic diversity. 11th hour efforts were launched by conservationists and park agencies to save the few remaining open linkages and critical choke points, such as Coal Canyon, San Fernando Pass, Santa Susana Pass, and Liberty Canyon in order to prevent areas such as the Whittier Hills, the Verdugos, and the Santa Monica Mountains from turning into biological islands. Money from state and county bond issues was used to buy undeveloped land around several of these endangered choke points to ensure they would stay open.

One of the best publicized of these choke points is the Liberty Canyon Interchange on the Ventura (101) Freeway five miles west of the San Fernando Valley. There is a small area of urban development on the south side of the Freeway here, but the land on the north side remains open, most of it part of the National Park Service's Cheeseboro Canyon. Malibu Creek State Park is less than a mile south of the Freeway at this point.

Valley Oaks in Cheeseboro Canyon. Cougar P-12 was recorded in this area just before he dashed across the Ventura Freeway about 2:00 a.m. on February 24. PHOTO BY DAVE BROWN

In the last 15 years the state has purchased a quarter mile wide corridor connecting the Liberty Canyon Interchange to Malibu Creek State Park. Native trees and shrubs have been planted to provide cover for migrating animals. In 2003 four cougars in the Santa Monica Mountains and the Simi Hills were radio-collared by the National Park Service. Two regularly crossed under the 118 Freeway using an old equestrian tunnel, but none showed any interest in crossing the 101 at Liberty Canyon. The state had built a wildlife corridor, but it seemed no animals wanted to come.

A landowner who refused to leave an open space buffer next to the interchange, narrowed the corridor to 20' of state right-of way at the interchange, casting doubt on the future viability of the corridor. Yet, by just this narrow thread at the Liberty Canyon Interchange, 50 miles of the Santa Monica Mountains from Griffith Park to Point Mugu remained tenuously connected to large blocks of habitat in the Simi Hills, the Santa Susana Mountains, and, ultimately, the San Gabriels.

Then late last year a new Cougar, named P (for puma) 12, a 135 pound, two year old male, showed up in the Simi Hills. Soon the Park Service had put a radio collar on him and his movements were being tracked every two hours.

Late in February P12 began moving south in Cheeseboro Canyon. At 1:00 on the morning of February 24th, his radio signal was picked up a few hundred yards north of the Ventura Freeway. Two hours of silence followed, but when P12 broadcast again at 3:00, he was several hundred yards south of the Freeway. Somehow P12 had managed to make the run. 15 years of work had produced a tenuous, but workable wildlife corridor.

Park Service biologists have been unable to find tracks or other evidence of the exact point where P12 crossed the eight-lane Ventura Freeway, but they suspect it was at the Liberty Canyon underpass.

At last report P12 was hanging around Malibu Creek State Park with no barriers to prevent him from roaming from Point Mugu to the 405 Freeway.