Has the San Bruno Mountain HCP improved the butterflies’ chances? This and other basic questions remain unanswered, even as development continues. The plan itself entails no independent scientific review, and none exists.

HCP advocates say they are effective; opponents see them as mechanisms to allow developers to subvert the ESA. Under the 1983 amendment, the Secretary of the Interior can allow landowners and developers to destroy listed species’ habitat if they pay for measures that improve these species’ survival prospects, and dedicate some land for that purpose.

At San Bruno Mountain in 1982, defenders of the area’s unique plant and wildlife communities had already defeated giant development plans and helped create San Bruno Mountain State and County Park, encompassing some 1,950 of the mountain’s 3,600 acres. Then the endangered mission blue butterfly turned up on private land. To avert court battles, a committee of landowners, developers, local governments, the U.S. Fish and Wildlife Service, the California Department of Fish and Game and some others crafted a plan in 1982 “to address problems caused by the presence of endangered butterflies on San Bruno Mountain.” (Butterfly advocates might have attributed the problems to a different source.)

The HCP allowed development of 368 to 828 acres, at the cost up to 13 percent of mission blue and 14 percent of silverspot habitat. Fish and Wildlife issued an Incidental Take Permit for 15 years—then renewed it for another 15.

Property owners who built were required “to increase their [the butterflies’] chances of survival” by offering land and providing funds to conserve and improve habitat elsewhere on the mountain. A Habitat Conservation Trust Fund, funded by assessments on property holders, pays for species monitoring, alien plant removal, and other measures. The environmental consulting firm Thomas Reid Associates (TRA), which conducted the biological and environmental impact studies required for the HCP and produced the plan itself, is carrying out the biological program, and also monitors results of its efforts. TRA’s contract, with San Mateo County, the HCP operator, is put up for bid each year and has been renewed each year. “We’ve accumulated so much data that it’s hard to compete with us,” explained TRA’s Patrick Kobanus, the ecologist in charge.

TRA works with others to protect butterfly habitat against alien plant invasions. It also tries to replace some of the lost habitat, but with little success. For example, a residential community was built on prime butterfly habitat on the northeast ridge, but habitat was to be restored on the mountain’s saddle. The saddle is colder, damper, and windier, not nearly as attractive either to butterflies or people as the northeast ridge.

The saddle was—and still is—overgrown with gorse, but the mission blue’s host is lupine, which thrives in the grasslands on the northeast ridge. The HCP did not require any evidence that the butterflies could be relocated, but an attempt to replace gorse with lupine began in 1985.

This proved difficult. Gorse can be 20 feet tall, with a huge, deep root system, says TRA’s Patrick Kobernus, an ecologist on the project for six years. Many methods were tried, including herbicides and burning, but in April the yellow bloom was bright on the saddle. According to Kobernus, the gorse covers only 100 acres, down from 330 acres in 1982, but is now more dense. He added that butterflies have moved into three of 15 quarter-acre “habitat restoration islands.”

Paul Reeber, a botanist with TRA from 1985 to 1989, observed that “the idea of trading habitat is scientifically flawed and very dangerous.”

Kobernus contends that the HCP has achieved its primary goal by finding a permanent source of funding for alien species removal. Without that money, he says, dozens of invasive plants—including fennel, broom, eucalyptus, and gorse—would have overwhelmed butterfly habitat.

More development, of course, will destroy more habitat and new residents will bring in more nonnative plants, requiring yet more costly eradication efforts. Already the funds are inadequate—according to TRA it can cost $3,000 an acre each year to control gorse, although Kobernus thinks this could go down to $200 an acre if “you . . . come back and keep treating seedlings for five to ten years.”

The Coastal Conservancy has approved a $45,500 grant to San Bruno Mountain Watch, a citizens’ group which has had good results in removing gorse on a nearby ridge using hand tools rather than herbicides and mechanical methods.

It is hard to say how much land developers have provided, as many offers have not yet been accepted.

Another San Bruno Mountain butterfly, the callipe silverspot, has been listed as endangered. Mountain Watch went to court to prevent its inclusion in the existing HCP, opening the way for Fish and Wildlife to see if this HCP is a win-win for property rights and species survival rights, as intended.

—RG