H o’olaukanaka i ka leo o na manu
The voices of birds make the place feel inhabited
Take Miconia calvescens, a tree from Central and South America that goes by the name “green cancer” in Tahiti, where it covers threequarters of the island. Biologists Betsy Gagne and Steve Montgomery launched a campaign in 1977 to get Hawaii to stop importing the invader. But petitions failed to persuade the state’s Department of Agriculture to put the plant on its Noxious Weed List, which prohibits importation, until 1992.
The slogging combat seems to be working: Kauai could soon eradicate miconia, Maui has brought the pest to heel, and the Big Island, with the worst infestation, has set its sights on eliminating 95 percent of the plants by 2006. Still, faster action could have saved Hawaii millions of dollars.
“I could come into Hawaii tomorrow with a whole bunch of plants from Southeast Asia, and as long as they didn’t have any insect pests, I could bring them in,” says Charles Lamoureux, director of the Lyon Arboretum at the University of Hawaii at Manoa. What’s needed, he says, is a broader Noxious Weeds List. Others call for tougher measures, such as a list of plants permitted for import, with all others banned; Hawaii already has such a list for animals. But the state’s powerful nursery industry is opposed to stricter controls, so the chances of seeing new regulations on plant imports anytime soon, Lamoureux admits, are “probably nil.”
Paleontologist Helen James spends her days searching for clues as to exactly when the clock ran out on many Hawaiian species. By studying avian bone fragments, James and husband Storrs Olson, both of the Smithsonian Institution’s National Museum of Natural History, have pieced together a picture of bird life before the first Polynesian settlers arrived sometime between a.d. 400 and 600. “Nobody wanted to look at these little scraps,” says James, who collects them from lava tubes—tunnels formed when lava solidifies around an active flow. After the eruption stops, the tube empties; the resulting caves, sometimes miles long, shelter fragile songbird bones that wash into the porous floors.
Like a volcanic assembly line, each Hawaiian island was forged from magma welling up from a hot spot in the middle of the Pacific Ocean, then inched, with the Pacific plate, in a northwesterly direction toward Japan. Kauai, the oldest of the main islands, accrued over the hot spot about 5 million years ago. The newest, Hawaii, which locals call the Big Island, began forming about 500,000 years ago and is a work in progress: Lava flowing from Kilauea adds new shoreline all the time. Next down the chain is Loihi, an underwater volcano southeast of the Big Island that’s less than 3,100 feet from the surface and rising.
The first pioneers to reach this remote archipelago more than 2,000 miles from the nearest continent undoubtedly arrived by accident. They were birds blown in by storms, or spores and pollen swept in by wind and ocean currents. Many of the estimated 270 founding plant species and 300 to 400 insect colonists made landfall on these islands millions of years ago. Their struggle to eke out an existence in the harsh new land nurtured genetic mutations that led to favorable adaptations in the pioneers, thus spawning hundreds of new life-forms. For example, from a single species evolved almost 50 types of Hawaiian birds called honeycreepers, each with a beak or a tongue shaped differently to exploit various food sources. The fast and furious adaptive radiation of honeycreepers rivals that of finches on the Galápagos Islands, another case study in how natural selection marches at double time in the confines of isolated islands.
Some of the cruelest blows to Hawaiian birds, James and Olson have found, were meted out long before any Europeans set foot on the islands. They estimate that more than 50 unique bird species, including a majestic ibis, went extinct between a.d. 600 and 1800, when the Polynesian population was growing rapidly. They farmed lowlands and feasted on such seabirds as the dark-rumped petrel, which were easy to spear in their shoreline burrows. “We have sites with tremendous numbers of petrel bones,” James says. Native life also took heavy hits from pigs, chickens, and dogs—which the Polynesians brought for their dinner table—and rats that stowed away on their ships. The livestock trampled and devoured native vegetation, while the rats gnawed through a cornucopia of native snails. “We see not just the loss of rare species, but a huge loss of abundance too,” James says.
The decline of Hawaiian species accelerated after Captain James Cook and his crew, the first Europeans to visit the islands, arrived from England in 1778. Besides waves of immigrants, subsequent European and American ships brought in rats that, unlike their Polynesian cousins, could scurry up trees and snatch eggs from nests. In a nightmarish incident on Maui in the 1820s, an American ship arriving from Mexico dumped water contaminated with larvae of Culex quinquefasciatus, the mosquito that carries avian pox and malaria. By the early 1900s, most remaining native songbirds had retreated to the mountains, away from the diseased growing communities hugging the shore.
Irked that the music in the trees had all but ceased, a ladies’ club called Hui Manu imported the Northern mockingbird, the Japanese white-eye, the Japanese bush warbler, and at least a dozen other kinds of songbirds in the 1930s. The invaders overran the lowlands and advanced into the hills, eating away at the native birds’ remaining habitat. In addition, just about any kind of plant could be imported to Hawaii, so long as it didn’t threaten the pineapple or sugarcane industries. Nursery plants escaped and became weeds.
Early efforts to protect Hawaii’s ecosystems floundered. An experiment late last century to bring in mongooses to control rats failed miserably: Somehow, nobody had anticipated that the Indian mongoose, which hunts by day, would rarely encounter the rats, which forage at night. Instead, the mongoose nearly wiped out a native goose, the nene. Galvanized by public concern, the Territory of Hawaii organized a breeding effort in the 1930s to save what would later become the state bird. “The nene caught people’s attention; it was somehow charismatic,” says Paul Banko, a wildlife biologist with the Pacific Island Ecosystems Research Center. By the mid-1970s, however, scientists “were really getting tired of hearing about nenes,” Banko says. By then the program had churned out 1,500 birds on the principle, he says, of “let’s make more of them, put them out there, and hope for the best.”
In the mid-1950s, Hawaiian officials imported the carnivorous rosywolf snail from Florida to knock off the giant African snail. The Floridians soon decimated native snails as well.
Today Hawaii’s 900 nenes are “far from recovered,” Banko notes, and their reproductive success is declining, perhaps due to inbreeding. Meanwhile, a high-profile captive breeding effort to save the Hawaiian crow, or ‘alala, has suffered serious setbacks: Crows released into the wild are getting picked off by hawks and mongooses or dying of infections such as toxoplasmosis, caused by a cat-borne bacterium. Only three wild ‘alala and 26 captive ones are left.
Bones of another forlorn bird—the po‘ouli—dot volcanic lava tubes on the leeward slopes of eastern Maui where James and Olsen have done much of their digging. The ranks of the po‘ouli, a brown bird with a creamy tan belly that tears at bark to get at juicy larvae hidden beneath, had already dwindled to about 50 a quarter of a century ago. Today only three po‘ouli are known to exist, dwelling in separate areas of the forest. After an agonizing debate, scientists have decided to move a male bird into the territory of one presumed to be female. The faint hope is that the two will find each other desirable.
“It’s too late for the po‘ouli,” James says. The bird is now making its last stand on the windward side of eastern Maui. Birds that refused to budge from the leeward side died out long ago. James sometimes imagines their coming back to life. “I’ve seen them in my dreams a lot,” she says.
Ha‘alele ‘ia i muliwa‘a
Left on the very last canoe
Kauai’s Na Pali coast was once covered with native shrubs and trees. Then came goats, courtesy of Captain Cook. Today, the natives survive only on cliffs so steep that feral goats can’t reach them.
Hawaii has lost so much of its native life already, a fatalist might argue, that it may as well lose the rest. Seen as part of the grand order of succession, today’s aliens are no more than tomorrow’s familiar faces. Today’s songbirds are tomorrow’s paleontology project. Today’s lush Hawaiian Islands are tomorrow’s barren rocks. Why fight for the transitory pleasure of seeing a live po‘ouli, when it’s destined for a museum display? Why not let nature run its course?
Jim Jacobi rejects that attitude unequivocally. “Some of the things I’m doing do make a difference,” he says. But the success or failure of his cause will depend on whether he and his colleagues can stitch together a healthy ecosystem—one capable of supporting the natives—from the remaining salvageable land. In that spirit, Jacobi has forged a fragile coalition to build a preserve on the Big Island, on land managed by the state, the National Park Service, the privately held Bishop Estate, and the Kulani Correctional Facility. Safeguarding the sanctuary will mean banishing key alien species that threaten to irrevocably alter the ecosystem. Inmates have therefore built 12 miles of fence to enclose about 4,000 acres of upland koa-‘ohi‘a forest, and state and federal workers have shot and removed most of the feral pigs inside the fences. Signs of pigs—denuded wallows or broken tree ferns ravaged for their starchy core—are beginning to fade.
Inside the fence, a terse sound, something like phit-ier-ieu, filters from the understory. “That’s an ‘akiapola‘au,” Jacobi says. Searching with binoculars, he spots a yellow bird picking at a branch with its sharply curved black bill. Like many other Hawaiian songbirds, the ‘akiapola’au, found only on the Big Island, is endangered. Ornithologists aren’t sure what plagues it the most: predators, disease, or loss of habitat. “The really frustrating thing is not knowing what we can do,” Jacobi says. And yet, the simple fact that the ‘akiapola‘au’s song can still be heard suggests that much can be gained by intervening, no matter how uncomfortable that might be for ecologists accustomed to observing the world dispassionately.
Fencing off a forest is an act of desperation, but at least it offers the ‘akiapola‘au hope of survival. That’s something the o‘o, and many other Hawaiian species, never got.