Massive Wave of Extinction Perils County Wildlife : Ecology: Biologists find isolated islands of open space can’t sustain animals. Mountain lions may be among the first to go.

The field of locoweed in Rancho Palos Verdes didn’t seem special. It looked like the same golden, bushy growth that had covered much of Southern California’s landscape before the bulldozers arrived to build homes and plant palm trees.

So, when the city flattened the flowering plants to build a baseball diamond, few people cared. But the ball field wiped out the last home for a cluster of delicate blue butterflies, and soon, the butterfly will be erased from the federal endangered species list and officially classified as extinct.

The same fate awaits one-third of Southern California’s native animals unless the pace and pattern of development changes dramatically by the end of the decade, wildlife biologists say. In San Diego County alone, development threatens the habitat of dozens of animals, including the golden eagle, the mountain lion, several rare songbirds, marsh birds and raptors, various reptiles and even the mule deer.

Because the threat is so broad and severe in Southern California, scientists and conservationists are advocating a new approach to wildlife protection and local land-use planning. Overhaul the system, they say, so that entire habitats and broad swaths of land called wildlife corridors are preserved, not just isolated patches of open spaces.

“If we do not act now, it is likely that, within decades, not centuries, the habitat destruction we are causing will lead to a massive wave of extinctions,” says a new report by UC Berkeley environmental scientists.

Although developers often leave parks or preserves, a study in San Diego County documented that all native species begin to disappear fairly rapidly on small parcels of land, even if the vegetation is left undeveloped.

The mammals, birds and native rodents on 37 parcels of chaparral and scrub between Encinitas and Point Loma gradually disappeared, replaced by urban cats, skunks and rats, said Michael Soule, chairman of environmental studies at UC Santa Cruz and founder of the Society for Conservation Biology, a group of scientists.

“The patches may look healthy, but the native flora and fauna disappear very quickly, over a matter of a few decades,” said Soule, who studied habitat disruption in San Diego County.

Soule, who lived in San Diego most of his life, called the changes in the county’s habitat, especially in North County, “horrendous.”

His 1988 study found only a few individuals within each species survived on patches of less than 100 acres, too few to ward off inbreeding and ensure adequate exchange of genetic information. Also, without corridors linking the patches, large animals such as coyotes cannot get in, and nature’s precarious balance of prey and predators is disrupted.

The steady bulldozing of the region’s native grasses, shrubs, marshes and woodlands is turning Southern California into the nation’s epicenter of extinction, causing more sweeping losses of natural lands and threats to entire ecosystems than any other part of the United States.

Many Americans presume that the war to protect wildlife is waged in the jungles of exotic, faraway places. But some of the world’s worst battlefields are right here. The newest threats to wildlife are developments breaking up the back country in the canyons of northern and southeastern San Diego County, southern and eastern Orange County, and western Riverside County.

For 20 years, the conservation movement has focused on individual crusades--Save the Whale, Save the Redwoods, Save the Desert Tortoise. Now, wildlife biologists are urging local governments and developers to pay more attention to the big picture.

Setting aside a parcel of land to save a species is no longer working in Southern California, state and federal biologists say. The region is left with islands of greenery that are big enough for picnics but too small for animals to survive.

Instead, wildlife biologists say local governments and developers must preserve a network of lands linked together by wildlife corridors, wide paths of undisturbed land that allow animals to hunt and breed without encountering freeways, houses and malls. The Berkeley report advocates passage of an Endangered Habitat Act that would significantly restrict development.

“Fragmentation of habitat is one of the biggest causes of loss of species in Southern California,” said John Hanlon, a biologist in the U.S. Fish and Wildlife Service’s regional office. “Developments are filling in the streams and drainage areas that serve as corridors for wildlife, and it creates islands of habitat. The size is unsuitable, so the species become extinct in that area.”

In September, a federal appeals court recognized this emerging approach to conservation by rejecting a timber-cutting proposal in Northern California because it preserved only a half-mile-wide strip for migration without proving it was large enough to sustain wildlife.

“We’re beginning to hear more and more that this species-by-species program we’ve followed for so long has not kept pace, especially in Southern California,” said David Klinger, a spokesman for the U.S. Fish and Wildlife Service, the federal agency that monitors endangered species. “A lot of our program has been reacting to a crisis as it occurs.”

About 90% of Southern California’s oak woodlands, coastal sage scrub, chaparral and fresh and saltwater wetlands have disappeared, and much of what remains is split into isolated patches, according to the state Fish and Game Department.

So many animals and plants are at risk in the region that biologists are calling it a crisis in biodiversity, the rich mosaic of ecosystems, species and genes that defines life on Earth.

The problem is so extreme because the state has more plants and animals that exist only within its borders than anyplace in the United States except Hawaii, and all are competing for the same patches of land as the nation’s fastest growing population.

“Something has to give, and I’m afraid it’s not going to be people,” Soule said.

To city officials, planners and developers in Southern California, the issue often comes down to affordable housing versus wildlife. Putting restrictions on land use or preserving more open space costs money and eventually leads to higher housing costs, said Dwight Hansen, a lobbyist with the California Building Industry Assn.

Despite rapid development, new housing is still in demand. Fewer than 200,000 units are being built this year in the state, less than half the annual number needed to house the influx of newcomers, according to the building group.

“The most endangered species in California may be the first-time home buyer,” Hansen said. “There’s probably more land for some of these species than there is for first-time home buyers.”

But wildlife biologists are more concerned right now with mountain lions, which already have vanished in the past few years from Orange County’s coastal San Joaquin Hills because their routes were cut off by patchwork development between Laguna Beach, Irvine and the Newport Beach coast, said Paul Beier, a biologist and project leader for a state Fish and Game Department cougar study.

Now Beier is worried that cougars will vanish soon from another major wilderness area that straddles San Diego and Riverside counties around Pechanga Creek and Palomar Mountain. He said tract homes and a golf course already have degraded the area, and more are planned.

The developments there, Beier said, are a major threat to the 20 or so remaining cougars in Southern California.

The disappearance of the top predators, which need wide corridors and a range of at least 100 square miles, is considered the first step toward turning the area’s once-rich canyons into a biological desert. Next to disappear could be coyotes, deer and rare birds like the gnatcatcher and cactus wren.

Symbolically, California’s state animal, the grizzly bear, is extinct within its borders. At least 36 other animals, including gray wolves, condors, and white-tailed deer, are gone from the state, and about 220 more plants and animals in California are on federal or state endangered species lists. As many as 900 are considered seriously at risk, according to Fish and Game Department estimates.

Scientists don’t know what such losses would do to the planet’s complex web of ecosystems. But they worry that, if a habitat cannot keep animals alive, it eventually won’t sustain human life, either.

When bulldozers scrape off the golden scrub in Southern California’s canyons or pave a riverbed, it doesn’t have the emotional impact of ancient redwoods crashing to the ground or tropical rain forests slashed and burned.

As a result, conservationists and officials say they have difficulty rousing the public to the cause of wildlife in Southern California. The region’s threatened or endangered animals are so obscure that most people have never heard of them--such as the gnatcatcher, the cactus wren, the kangaroo rat, the horned lizard, the clapper rail, the least Bells vireo, the orange throated whiptail.

But biologists say the disappearance of the kangaroo rat is just as much a signal that the region’s biodiversity is in trouble as the loss of the beloved bald eagle.

Builders also believe the piecemeal approach to conservation is failing. They say wildlife experts should agree on land that is a priority to protect, but then restrict its use only if its owners are compensated.

“People think they should donate land or walk away from millions of dollars of investments,” Hansen said. “To ask an individual landowner to give his land to the people of California without compensation is unfair.”

Part of the conflict between biologists and developers arises from the fact that conservation is an inexact science: no one agrees on how wide wildlife corridors should be, where they need to go, or whether a bridge or culvert is adequate.

Beier, the cougar expert, has an admittedly vague definition of a wildlife corridor, “It’s not an area so narrow that you dare an animal to cross.” He recommends at least a half-mile wide swath, saying the narrow bridges and underpasses often left by developers aren’t enough.

Biologists, however, consider the efforts of the region’s planners and developers too little, too late, and dub their mitigation measures “the loser’s prize.”

In its strongly worded report published this summer, UC Berkeley’s Energy and Resources Group recommends immediate actions by the Legislature and local government. “In Our Own Hands: A Strategy for Conserving Biological Diversity in California” was written for the California Policy Seminar, a joint program that links the universities and state government, by John Harte, a professor of energy and resources, and two of his students.

The report blames county and city land-use planning for much of the loss of wildlife. Local officials have the authority to require developers to leave migration corridors and open space, but there is no regional or even county-wide perspective, so each development is done piecemeal.

The UC team advocates a 10-step strategy, including creation of a new state agency to monitor threats to biodiversity and passage of a unique state Endangered Habitat Act that would force major concessions from developers.

The existing law--the national Endangered Species Act adopted in 1973--requires federal officials to list and protect rare species. The law doesn’t prohibit private landowners from harming the species; it only requires them to try to avoid it.

At least six species have been wiped out despite being on the federal list, and there is a national backlog of about 4,000 species waiting to be considered.

Under the UC team’s idea, an animal wouldn’t have to be rare to be protected. Instead, the state would declare the entire land type--such as the coastal sage scrub that lines canyons in San Diego County--endangered, protecting habitat before species teeter on the edge of extinction. Developers would have to obtain state permits to build on it and prove they would not harm the habitat.

So many special interest groups are involved and lobbying is so intense that legislators have been wary of tackling the issue of protecting habitats, said Edna Maita, consultant for the state Assembly’s Water, Parks and Wildlife Committee. When the Legislature adopted the California Endangered Species Act in 1984, it came after years of debate between city officials worried about losing local control, conservationists, developers, business groups and ranchers and farmers.

“The goal is laudable. But politically it is a difficult process,” Maita said. “There’s been a reluctance to dig into it. The last bill in 1984 took a lot of negotiations.”

Spurred by dire warnings in recent reports, a state Senate committee has started kicking around ideas for new conservation legislation. But experts said there is little hope of getting a law in place soon.

“Development forces were caught sleeping when the federal Endangered Species Act was passed. They’re not sleeping any more,” Soule said. “They’re wide awake and very powerful. In the long run, though, it may have a chance. We ought to at least put these issues out on the table.”