he aki is a spectacular example of evolution at work -- and of the sometimes profound errors in conventional wisdom.
The aki is not the only feathered exotic that evolved in Hawaii's forests, but it is one of the few survivors. Twenty-pound flightless ducks once waddled here on thick legs, browsing on ferns and grasses that grew nowhere else. Rails -- swamp-loving birds that in other parts of the world sport long, slender legs -- also gave up flying and walked on stumpy limbs. A Hawaiian owl grew extralong legs designed to capture small forest birds. A single drab species of finch gave rise to a whole family of honeycreepers, bright little birds with a bizarre array of bill types and survival strategies. In the absence of mammals (other than bats), reptiles, and amphibians, which had never made it across the ocean, birds filled every possible niche.
Jack Jeffrey has spent decades working to restore these woods. He and his colleagues, along with dozens of volunteers, have managed to bring back a thin slice of primeval Hawaii -- a world that has been dwindling for close to 2,000 years, since the first Polynesian settlers landed. When those long-ago explorers stepped out of their canoes, they brought with them the dog, the pig, and the Polynesian rat, the first wave in a tide of invasive species that would sweep most of Hawaii's native birds away forever.
Newly arrived mammals -- humans included -- found earthbound birds easy prey, and some species were long gone by the time Captain Cook came ashore, in 1778. European contact accelerated the extinction rate. Cattle and goats teamed up with pigs to reduce forests of koa and ohia trees to barren pasture. Mongooses and domestic cats, both efficient bird hunters, were brought to the islands. One of the worst blows to the bird population was the accidental introduction of mosquitoes, which carry avian pox and malaria. At the turn of the last century, whole communities of native birds suddenly vanished from Hawaii's forests, wiped out by mosquito-borne disease. These days, native forest birds are found largely at higher elevations, where mosquitoes are few or absent.
Nineteenth-century European ships also imported black and Norway rats. The black rat, an acrobatic climber that can reach and raid any nest, is now a major threat to the birds that have so far survived the invasive blitzkrieg.
In the early 1890s, Hawaii was home to about 70 species. Today 26 of those birds are extinct, and 31 more are endangered. Twenty-nine of the 90 birds on the U.S. list of threatened and endangered species are Hawaiian.
In this bleak scenario, Hakalau, high above Hawaii's romantic but mosquito-infested beaches, represents a growing oasis of hope. The refuge lies on the eastern, windward face of 13,000-foot-high Mauna Kea, in the heart of the Big Island, the southernmost in the scattered Hawaiian chain. With cattle and pigs fenced out and a careful campaign under way to remove invasive plants and replant koa trees and other native species, Hakalau's forest is making a dramatic recovery. Beneath the ancient ohias, native versions of huckleberry and raspberry, which had vanished into bovine stomachs during decades of ranching, have returned.
Populations of some native birds are also blossoming. The Hawaii creeper has doubled in number since restoration work began, and the akepa, a crossbilled honeycreeper whose orange plumage stands out like a Day-Glo safety vest against the foliage, is also on the increase. Akis remain so rare that any trend in their numbers is impossible to detect, but at least they are still here -- they exist only in and around Hakalau and in three other scattered remnants of habitat on the Big Island.