Visitors to the recent Hands Across the Mountain celebration on Montara Mountain may have included a surprise guest: an endangered San Bruno Mountain elfin butterfly.
Two environmentalists, Pacifican Mike Vasey and David Schooley, a member of Bay Area Land Watch, said last week that on May 26 they photographed one of the butterflies in its larval stage. The butterfly, which is listed under the federal Endangered Species Act, was discovered on Montara Mountain about 50 yards from the proposed route of the Martini Creek Bypass.
The elfin butterfly used to populate that area, but has not been documented with photographs for about 10 years, Vasey said. Colonies exist on Milagra Ridge in Pacifica and on San Bruno Mountain.
"It's a pretty exciting find," said Vasey, adding, however, that the pictures have yet to be returned from a photo lab and that the butterfly has not been confirmed as an elfin. He and a friend, an entomologist specializing in butterflies at San Francisco State University, plan to visit the site again to try and confirm the find.
Schooley, who has been tracking the butterfly for 12 years, was somewhat surprised by the find. He said a colony in the same area was wiped out about five years ago when a small fire was started by a nearby plane crash.
Schooley spotted the butterfly after attending the Hands Across the Mountain ceremony atop Montara Mountain. Since he was near the butterfly's former habitat - a big, rocky ridge surrounded by scrub brush - he decided to take a look.
He reportedly found the larva munching on a stonecrop plant, its food of choice.
The elfin butterfly is brown with bright red marks on its back and a wingspan of about one inch. Schooley said it could not have been introduced to the site artificially.
"It would be too fragile and delicate to take from one place to another," he said.
The red-legged frog, another endangered species, has been documented in ponds that are directly in the path of the bypass. The California Department of Transportation has not said how it plans to protect the frogs or if they would replace the destroyed habitat with a new one elsewhere. In addition to the frog, Vasey said it is believed that Hickman's cinquefoil, a rare plant, grows on Montara Mountain, and that steelhead trout may be returning to San Pedro Creek in Pacifica.