A mountain lion has been seen intermittently on San Bruno Mountain, injuring no one but clearly demonstrating the environmental change afoot on the protected hillsides.
"It’s thought to be a young male. It’s been seen in the saddle area," said Patrick Kobernus, a senior biologist with Thomas Reid Associates, which manages 3,000 acres on the mountain protected as endangered butterfly habitat.
The mountain lion was first seen on the mountain in October 2004 during a project to pull out gorse weeds, according to San Mateo County parks and recreation planner Sam Herzberg. A sign to warn visitors was erected then, but the event largely passed unheralded.
It was seen again in the fall of 2005. Both times, it has been seen in an area highly used by visitors and families, but no attacks, or even other sightings, have been reported. People have seen tracks and scat containing rabbit fur from the animal, Herzberg said.
Kobernus and Herzberg speculated that it might be coming and going from the Crystal Springs area west of Interstate 280 and crossing Colma’s cemeteries, where food offerings to ancestors attract animals. It is not known whether it is related to the animal killed last month in a car accident on I-280.
It is not the only new visitor to the mountain. A black-tailed mule deer was seen there three months ago, perhaps the first deer seen on the mountain since the 1960s, Herzberg said. Formerly, the land was home to herds of cattle, and to tule elk before that. A bobcat was also seen recently, according to Philip Batchelder, executive director of the environmentalist group San Bruno Mountain Watch.
The visitors highlight changes coming to the mountain. Some would like to see a return of grazing animals, Batchelder said. Without them, and without the fires that used to rage across the mountain, brushy growth possibly fertilized by nitrogen from car exhaust has been overtaking the native grasslands vital to the endangered butterfly’s survival, Kobernus said.