Last Chance

An ice storm that sent a truck into a plane and a plane off the runway delayed my flight from Boston, but I was colder on the Big Island of Hawaii—at least the first night on Mauna Kea. The volcano—about a thousand feet higher than Everest, if you measure from its base on the ocean floor—blocked half the sky, including the Southern Cross. Visible stars, unsmudged by full atmosphere and ambient light and reflected by snowfields, illuminated my tent.

I had come here with U.S. Geological Survey wildlife biologist Paul Banko, palila project leader, to report on the state’s 30-year refusal (in violation of three court orders) to adequately protect the habitat of this forest bird, critically endangered by feral ungulates, mainly sheep, unleashed by European settlers and established in the wild on the Big Island as well as Kahoolawe (where they’ve been eradicated). In 1962 the state transferred wild mouflon sheep, native to Corsica and Sardinia, from Lanai (where they had been introduced as game) to the Big Island. It did this not for hunters, who generally preferred the less wary feral barnyard variety that were already trashing palila habitat, but in the belief that because mouflons have less of a herding instinct than the mouflon–feral hybrids, they would do less damage to the forest. As the managers had hoped, the mouflons hybridized the feral sheep out of existence, but the mongrels, which range higher and are able to leap the fences that had restricted their feral cousins, merely spread the damage.

Hawaii’s inattention to nongame (and it has no endemic wildlife that is currently game) is standard for American wildlife management. Here, as in most states, sportsmen wield enormous political power because their license revenue feeds and clothes managers. From the start Hawaiian hunters made it clear they wanted mouflon mongrels managed for their personal sport, not removed by state sharpshooters for the benefit of some dumb bird you couldn’t even kill. Typical of this mindset was the screed of Earl Pacheco, president of the Hawaii Island Fish and Game Association, in the July 10, 1974, Hilo Tribune-Herald. In it he scolded the “ecologically minded” for disapproving of invasive exotics, reminding them that “man too is an exotic animal in most parts of this world” and that, therefore, feral ungulates “rightfully deserve to remain part of Hawaii.” And besides, he had divined that it wasn’t sheep that were doing in palilas but “adverse weather” and “volcanoes.”

Banko has been a resident of the state since 1965, when his father, noted biologist Winston Banko, was assigned by the U.S. Fish and Wildlife Service to determine why so many of Hawaii’s birds were disappearing. Now, thanks in no small part to both Bankos, the answers are clear. Shortly after the islands rose from the sea they were colonized by sundry ducks, geese, water birds, owls, hawks, corvids, and finches—possibly house finches but more likely Eurasian rosefinches. With no mammalian predators, few parasites or pathogens, and enormous food supplies they rapidly evolved into dissimilar species that filled all available niches. Waterfowl became flightless herbivores. Corvids became fruit eaters (just one of five species survives and, as of 2002, only in captivity). A waxwing-like bird sired five species of honeyeaters (all extinct). In the most dramatic of any “adaptive radiation” among birds, including that chronicled by Darwin on the Galápagos Islands, the finch produced no fewer than 56 species of honeycreeper, each specialized to feed on various insects, seeds, or nectar (39 are definitely extinct, 4 probably extinct).

The same isolation that enabled this dazzling diversity enabled its demise. When the Polynesians arrived, about a thousand years ago, they plucked the trusting, flightless geese and ducks from grasslands, shrublands, and woodlands as if they were buffet meat, and they brought with them rats that feasted on the eggs and hatchlings of most every Hawaiian bird. The only surviving endemic goose is the nene—the one proficient flier (another may have been able to take briefly to the air). And only two native ducks survive—the Koloa and the Laysan, both strong fliers.

Starting in the late 1700s European settlers unleashed a plague of aliens. Goats, sheep, horses, and cattle destroyed grassland and forest habitat. Norway rats, black rats, and feral cats proliferated on a solid bird diet. Pigs not only trashed habitat but devoured eggs and hatchlings of ground nesters. Avian pox arrived with chickens, avian malaria with other alien birds, and mosquitoes (which arrived as larvae in water tanks) spread both diseases. Mongooses, brought in as rat control, ate eggs and birds instead.

Because Hawaiian birds evolved with only avian predators they drop to the ground and freeze—an adaptation as effective in avoiding raptors as it is in becoming food for mammals. Today about half of all Hawaiian birds are extinct, about half the remainder face extinction, and about half of all threatened and endangered birds in the United States are Hawaiian.

The palila—the last finch-billed honeycreeper on the eight main islands from an original array of something like 20, is sustained mostly by seeds of the mamane tree. Before humans arrived it also occurred on Oahu and Kauai; now it exists only in the subalpine forest of Mauna Kea—about five percent of its original habitat. Since 2003 the estimated population has dropped from 5,354 to 2,640. There’s time to save the palila, but if the trend is allowed to continue, it could be extinct in four years. 

Earlier in the day Banko and I had climbed Mauna Kea’s north slope, stopping in mamane groves to suck in thin air and listen for palilas. The black, cinder sand was laced with the tracks of alien wild turkeys. To our south, and almost as high as Mauna Kea, loomed the former palila stronghold, Mauna Loa, the planet’s biggest volcano with a mass far in excess of the entire Sierra Nevada range. Thirty-five miles to our north rose the jagged peaks of Maui. Below us and to the east—in the cattle pastures where palilas used to shuck mamane seeds—a century-old, olive-green lesion of alien gorse metastasized toward the bird’s remaining habitat. Further east and below us the “trade wind inversion”—a thick band of clouds formed when descending cold air meets ascending, moisture-laden sea winds—obscured a montane forest of ohia and koa trees.

Downslope from the inversion, habitats are wet. At 3,000 feet, the montane forest receives 250 to 300 inches of rain a year. But above 6,000 feet the subalpine forest gets only about 24 inches. Mamane and naio trees start petering out at about 9,000 feet and at 9,500 give way to lava, cinder, and a few puakeawe shrubs. Above 11,500 feet about the only plant that can make it is the silversword, just as endangered as the palila and for the same reason. Like mamane it is relished by sheep.