Rare and Endangered Species on Montara Mountain

by Peter Drekmeier

The listing of the California red-legged frog (Rana aurora draytonii) as "threatened" on May 20, gave Caltrans yet another reason not to build the proposed freeway bypass. During the summer of 1995, a large population of the rare amphibian was found directly in the route of the project.

Red-legged Frog
Photo by Peter Dreckmeier

Now that the frog is listed, federal agencies must ensure that activities they authorize, fund or carry out will not jeopardize the continued existence of the species. The Endangered Species Act (ESA) also prohibits anyone from "taking" a listed species, which includes killing, harming or harassing the species.

Whereas an "endangered" species is immediately in danger of extinction, a "threatened" species is one that is likely to become endangered. The ESA protects both listings, with the difference that threatened status allows for more flexibility in managing the species.

Hickman's Cinquefoil
Photo by Mike Vasey

In addition to the red-legged frog, there are two other rare and endangered species on Montara Mountain; A plant named Hickman's cinquefoil (Potentilla hickmanii) and the San Bruno elfin butterfly (Callophrys mossil bayensis). Before its recent discovery on Montara Mountain, Hickman's cinquefoil was found only in one remote area near Monterey. That population of just 25 plants was thought to be too small to ensure the future of the species. But then the Montara population of between 2,000 and 3,000 plants was discovered along the route of the proposed bypass, offering hope for the species if the tunnel solution is chosen.

The San Bruno Elfin, which hadn't been documented in the area for many years, was rediscovered last May by David Schooley of San Bruno Mountain Watch during the "Hands Across the Mountain" ceremony. Mike Vasey was there to photograph the caterpillar and send the documentation to the appropriate authorities.

San Bruno Elfin
Photo courtesy of
Dave Schooley/Bay Area Land Watch

An interesting characteristic of the San Bruno elfin is its relationship with native ants. While in its caterpillar stage, the elfin secretes a sweet substance that is eaten by the ants. In return, the ants protect the caterpillars from predators and parasites. Besides Montara Mountain, the elfin can be found only in limited areas of San Mateo County, including San Bruno Mountain and the Sharp Park area of Pacifica.

The unique blend of coastal chaparral, coastal scrub and coastal prairie comprising the Montara/San Pedro Mountain ecosystem makes it different from any other place in the world. It is up to us to protect these natural wonders, and Measure T will do just that.

Back to previous article

Up to table of contents

Forward to next article