COLUMN ONE : Sad Aloha to Native Species : Much of Hawaii’s unique flora and fauna are gone forever, crowded out by imports. Now conservationists are fighting to save what’s left.

Much of native Hawaii--its lush rain forests and the noisy, colorful birds that inhabit them--is gone forever, and its remnants are hurtling toward the same oblivion in the worst extinction crisis in the nation.

Ravaged by species brought into the islands from other lands, Hawaii’s native birds and plants are succumbing at a rate that has made the 50th state the endangered-species capital of the nation.

A deceivingly lovely passion flower introduced as an ornamental vine is smothering the rain forests. A mongoose imported to kill rats that were damaging the sugar cane is preying instead on birds. A snail introduced to eradicate a farm pest has decimated the islands’ highly prized array of ornate-shelled native snails.

Although Hawaii comprises only 0.2% of the U.S. land area, the state accounts for more than 70% of extinctions in the nation and harbors more than 25% of the nation’s rare and endangered birds and plants. Almost half of Hawaii’s native birds are endangered and at least nine species have dwindled to fewer than 100 birds. Less than a quarter of the state’s native forests remain.

“The species loss here, compared to the mainland, is just fantastic,” said Charles P. Stone, a National Park Service research scientist based at Hawaii Volcanoes National Park on the big island of Hawaii. “Two-thirds of the native birds are already extinct.”

The losses of native species have been mounting for decades, but the crisis until recently has failed to attract much interest or concern. Lulled by a hospitable climate and oriented toward the islands’ stunning array of beaches, residents paid little heed to what was happening in the rain forests.

“Hawaii is such a beautiful place that it’s hard to think anything is wrong,” said Mark White, Maui project director for the Nature Conservancy.

Alien species frequently turn on native plants and animals, but Hawaii’s wildlife is particularly vulnerable to their scourges. Having evolved on the most isolated archipelago in the world, the native plants and animals did not have to fight for survival and therefore lack many of the defenses of their mainland relatives. When exotic species are introduced, the natives quickly succumb.

On the road to this volcano-crowned national park on Maui, rolling hills are carpeted with deep green grass and sprinkled with clusters of lanky eucalyptus trees. It is a pastoral scene, interrupted only by an occasional old plantation home. Closer to the park stands a small grove of stately pine trees, alive with birds and shading a needle-cushioned path below.

Albeit beautiful, most of it is imported. The grasses, the trees and the birds were brought here by man and eventually replaced acres and acres of rain forests and the creatures that depended on them. The plants and animals native to these settings--some of nature’s richest diversity--have been lost.

Armed with foundation money and encouraged by world concern over the loss of the forests and their inhabitants, conservationists and biologists from around the nation are trying to sound the alarm and save what remains. It is a formidable task.

At least a dozen new insects, plants or animals are introduced into Hawaii every year, exacerbating the already considerable threat posed by continuing development. The loss of one species, biologists note, can catapult into the loss of many.

“You just don’t know if you have pulled the thread that unravels the tapestry,” warns Kelvin Taketa, a Nature Conservancy vice president who directs the organization’s Hawaii and Pacific programs.

The losses are troubling for scientific as well as aesthetic reasons. Some native plants have been discovered to have cancer-fighting properties, and scientists believe other potentially useful extracts will be uncovered if extinctions can be staved off.

The genes of some native plants already have been used commercially to develop a more pest-resistant strain of cotton and a hardier ornamental hibiscus. An endemic plant whose leaves inhibit the formation of molds on food fed to laboratory insects also has cut research costs considerably.

Because of the islands’ isolation, the state provides an uncommon laboratory for biologists, entomologists and ecologists studying how life evolved on the planet and how to prevent extinctions. Indeed, Hawaii offers even more dramatic case studies of evolution than the famed Galapagos Islands, where Charles Darwin developed his theories of natural selection.

Created by undersea volcanic eruptions, the Hawaiian Islands were believed to have been colonized by a new life form only once every 100,000 years. Marine life was swept in on the ocean currents, birds flew in and other creatures and plant life made the long journey in the feathers of birds, in the mud on their feet or on floating logs or vegetation.

The imposing terrain of the islands restricted the movement of colonizing wildlife, and new species evolved to adapt to the islands’ myriad of climates--from rain forests to deserts, from sea level to elevations of nearly 14,000 feet.

Whereas Darwin’s famed finch evolved into 12 different species in the Galapagos, a finch that reached these islands evolved into at least 47 species or subspecies. From the ancestral finch, for example, came Hawaiian species that resemble a parrot, a blackbird and a woodpecker.

Because Hawaii has had only two native mammals, the now-endangered hoary bat and the monk seal, native wildlife lacks many traditional defense mechanisms. In the absence of herbivores, for instance, the thorns, thistles, toxins and odors that protect many plants slowly disappeared. The thorns on the raspberry bush turned to a soft fuzz. The native mint lost its protective odor.

Birds, too, lost some of their defenses against mammals. Survival was so assured that some birds produced only one chick at a time. Others became flightless or ground-nesters. With no ground mammals to eat them, some birds even developed the instinct to fall to the ground if their nests were disturbed.

Nurtured in such a benign environment, the natives rapidly perish when exposed to plants and animals from more demanding terrains. As more people move to Hawaii and try to replicate their homelands by bringing with them familiar animals and plants, the losses accelerate.

“This is really the front line,” said Stuart Pimm, a University of Tennessee zoology professor whose research often takes him to Hawaii. “This is where we are learning how to save species, how to save fragile communities and . . . tropical forests.”

Today, nearly 40% of birds unique to Hawaii are extinct and, of the 42 species that remain, 30 are classified as endangered or threatened. Forty percent of native plants either have been designated as endangered or are candidates for such classification. Few of the birds in Hawaii’s lowlands are native.

“It’s like a house of cards,” Pimm said. “When we lose one species in a community, we tend to lose another species and then another and another.”

On the big island of Hawaii, the contrast is stark between pristine forest lands and those that have been invaded by species from other parts of the world. Where there are no alien species, the rain forest is thick, tangled and dark. Twenty-foot-high tree ferns form a canopy that limits the light and filters the rain. The ground is spongy, and the flowers are subtle in color. An earthy, musty smell prevails.

But where pigs and alien plants run rampant, the canopy is gone. Introduced in large numbers for food in the late 1700s, pigs dig for roots and worms and eat rare plants that some of the native birds depend on for nectar. Left in the animals’ wake are large puddles, breeding ground for mosquitoes that carry diseases lethal to the birds.

Intensifying the damage, the pigs spread the seeds of such imported plants as the banana poka vine. This flowering vine climbs the trunks of the tree ferns, seeking light, and then spreads atop the canopy and crushes it. Sunlight and crashing rain pour in, killing the natural vegetation below and creating a favorable environment for alien weeds. At least 70,000 acres of Hawaii’s rain forests have been swallowed by the vine.

Signs of combat between the intruders and conservationists abound in Hawaii Volcanoes National Park. A footpath bears the sign: “Warning: Do Not Touch Nasturtiums Along the Trail.” The nasturtiums, which kill off the native vegetation, have been doused with a herbicide.

Forests are fenced to keep out pigs and many invading plants are dug out by hand. The pale trunk of a leafy, flowering 40-foot-tall hau kuahiwi tree, one of fewer than a dozen remaining in the world, is splashed with what looks like red paint. It is a rat repellent.

Rats eat tree fruit and flowers necessary for reproduction and, like the Indian mongoose, prey on birds’ eggs. The mongoose, brought here in 1883 to reduce the rat population, only increased the menace to native wildlife. A diurnal animal, the mongoose failed to control the largely nocturnal rats and instead devoured birds’ eggs and small ground-nesting birds.

“Whenever I see a mongoose,” said Dan Taylor, chief of resources management for the park, “I accelerate.”

The park boundaries provide telling examples of the losses. Just outside the park is a soggy cow pasture, its green grass in bog-like clumps dotted by an occasional tree. Slammed against the pasture is the abrupt wall of the rain forest, rising in a dense, tangled thicket behind a park fence.

Although the Park Service has worked over the years to save native species, its efforts are limited by park boundaries. The park was created to showcase the spectacular and still-erupting volcanoes, not the rain forest. Indeed, the richest, most diverse rain forests remain outside the island’s protected parks and wildlife refuges.

“If anyone tried to draw boundaries to exclude critical habitat for endangered species, they couldn’t have done a better job,” said the Park Service’s Taylor.

Native wildlife sheltered within the park finds perils just outside. The nene, an endangered Hawaiian goose and the state bird, is regularly clobbered by flying golf balls from a course at the edge of the park. A lowland rain forest not far from the park is threatened by geothermal development.

Until recently, ignorance was blamed for much of the apathy that allowed the forests to vanish. School textbooks geared toward the mainland teach children about such foreign species as cardinals, coyotes and bears instead of the native scarlet-feathered i’iwi, the red, black and white kamehameha butterfly or the native happy-faced spider.

Conservationists complain that even the federal government until recently showed a lack of interest in its Hawaiian refuges and parks.

“Hawaii is 5,000 miles away from Washington, D.C., and when people go to Hawaii, they don’t tend to visit the parks and refuges,” said Laura King, senior staff scientist of the Natural Resources Defense Council and director of its U.S. tropical forests program. “So their budgets are really tiny. Hawaii gets only 2% of the endangered species funding overall despite the fact that they have 25% of the endangered species.”

Nonetheless, interest in conservation here is now taking hold, spawned by an infusion of foundation money, a sympathetic new governor and the outcry over the loss of tropical forests worldwide.

Millions of dollars from the Chicago-based John D. and Catherine T. MacArthur Foundation during the last few years has enabled the Nature Conservancy to purchase more protective preserves and has helped several national environmental lobbying groups to open offices here. Foundation money also is paying for development of a curriculum for environmental conservation in island schools and for grants for scientific research in Hawaii.

Encouraged by the growing interest, the University of Hawaii is striving to develop a graduate program in the study of conservation biology--the application of science to saving species. Gov. John Waihee, the first native Hawaiian governor, has allocated more than $4 million to preserve and manage a network of long-neglected state-owned natural reserves and has pledged to find a permanent funding source for them.

Even though such progress gratifies conservationists, they lament that it did not come sooner. “I don’t know if it will be in time,” said Stone, the Park Service scientist. To save a declining species, he said, it is important to provide protection when the population is still relatively large. Native forest birds already are rapidly dwindling.

“Every year,” he said, “there are fewer and fewer. The forests are not silent, but the singing you hear is of exotic birds, not many of the natives. The natives go along pretty well for a while and then they just crash.”

The most recent casualty was the o’o’, a large brownish-black songbird with yellow feathers on its thighs and a long, curved bill and pointed tail. Hawaiian royalty used the bird’s yellow feathers for their cloaks.

By the mid-1980s, only a single male remained, on the island of Kauai. Scientists would beckon it by playing a tape recording of its call. The lone o’o’, mistaking the sound for another of its kind, faithfully answered in loud, clear, bell-like notes.

But recently, two intensive searches failed to uncover any trace of the bird, convincing scientists that the o’o’, whose melodious song once resounded throughout the Hawaiian forests, is now extinct.