The Kingdom of Rarities (31 page)

‘Akis were fortunate that a real woodpecker or sapsucker never landed on the Big Island or was introduced by some misguided bird lover. Without a sapsucker around to compete with, the ‘aki literally tapped into the most common tree on the island. Liba's findings also provided an important insight into how to conserve other rare species in a similar predicament. That ‘akis seemed actually to be nesting and raising young in the even-aged koa forests with no difference in reproductive success was particularly exciting to her. “This means that perhaps we could plant koas elsewhere on the Big Island and both provide habitat for an endangered species and provide landowners with a tree ‘trust fund' for their grandchildren.” My puzzled expression indicated to her that I didn't immediately see the connections. I understood the first part: if ‘akis and perhaps many other presumed old-growth-dependent bird species can reproduce well enough in immature forests, this is a measure of their resistance and resilience to extinction, and carefully designed forest regeneration programs could be truly beneficial to them.

Liba grew more animated. “Did you know that a koa dining room set goes for $12,000? And that individual koa-wood bowls turned on a lathe go for between $500 and $1,000?” Koa, Hawaii's premier hardwood, is referred to in some circles as “Hawaiian mahogany.” The tree is also important culturally, and some people were now planting koas to grow canoe logs for traditional purposes. “Koa stands,” she observed, “could provide a ‘win-win-win' for saving the ‘aki, bringing an economic return, and honoring Hawaii's traditional heritage.” Provided, of course, that the koa seedlings are planted above the mosquito zone.

Liba's hopeful story contrasts with David Steadman's ecological history, which tells us that the prospects for many island bird species are grim. Steadman's long view concluded that more than 50 percent of Hawaii's endemic birds went extinct with the arrival
of the Polynesians, another 20 percent had died off since 1825, and about 70 percent of the remaining birds were listed as endangered or threatened. Included on this list were eleven species determined to be basically unrecoverable or functionally extinct. Steadman summed it up to me this way: “The past few hundred years have only made the situation worse. While the surviving species of birds deserve our best efforts to save them from extinction, the sad truth is that there's not that much left to save.”

Steadman is right in one sense: It is too late to safeguard most of these avian rarities because many of them are already extinct. The question that remains is how fruitful would be any effort put into saving the remaining species. And if we were to make a concerted try, what would be the best method? Recovery efforts now under way involve both species- and habitat-oriented approaches to conservation. Although there are many rare species worthy of recovery efforts, the Hawaiian bird species receiving the most attention so far, in addition to the ‘aki, are the Hawaiian crow, the Hawaiian goose, and the palila.

The endemic Hawaiian crow, the
‘alalā
, was one of the rarest birds in the world when species recovery work began several decades ago. Biologists often joke that long after humans disappear and all the rare species before them, Earth will still be teeming with cockroaches and grasshoppers, with crows to gobble them up. Like other species of crows on Pacific islands, however, the Hawaiian crow is ecologically very different from our plentiful mainland crows. It is a forest bird, highly frugivorous, and it shuns agricultural and urban landscapes. “The ‘alalā has declined for many of the same reasons as have other native Hawaiian birds—loss of habitat, hunting, disease, and introduced predators,” Liba said. Before they can learn to fly, fledgling ‘alalās are caught on the ground by cats and mongooses. Avian pox and malaria have also taken their toll.

By 2004, the last wild ‘alalās were declared gone, so it is now up to the captive population to be the source of the recovery effort. The current ‘alalā captive breeding program on the Big Island contains
more than seventy-five individuals, but releases into the wild of captive-born young have been disappointing. Captive birds are treated for pox lesions before being released and their release area is beyond the malaria danger zone, but released birds are often killed by
‘ios
, native Hawaiian hawks. This circumstance is surprising because crows routinely mob and drive off hawks and eagles in other parts of the world. In Hawaii, even though the released birds seem to recognize hawks, they don't react. Experts have recommended removing Hawaiian hawks from the release sites by whatever means necessary, an ironic twist because the ‘io itself is an endangered species (although currently being considered for delisting). Better proposals are to liberate the chicks on another island where the hawks are absent or to free them in dense forests where ‘ios would be less common.

The prospects for the Hawaiian goose, the
nēnē
, is more optimistic. The nēnē looks far too tasty to have survived the Polynesian luau. A common phenomenon in native lands is the absence of rare vertebrates over the landscape—that is, until you hit pockets that turn out to be sacred areas where deities reside and humans dare not tread. The only reason the nēnē is still on the Big Island is that a remnant population of about thirty to fifty lived in the saddle between Mauna Kea and Mauna Loa, an area deemed kapu (taboo) and avoided by superstitious Hawaiians. Nevertheless, a concerted effort was required to coax the nēnē away from the gaping crater of extinction.

Today's stable population of almost 2,000 was achieved through captive breeding and release, the success of which depends on two factors: reintroduction into appropriate habitat and protection from predators. Adult nēnēs can fly, but they nest on the ground and the goslings are vulnerable for a long time. Soon after the recovery program began, it became clear that many birds released into marginal highland habitat that lacked abundant food plants subsequently perished. The nēnē's odds of survival in the wild picked up when mongooses, feral cats, and feral dogs were removed from the
area. Now, with a better understanding of the habitat and protection needs of this species, releases are targeted more effectively. On Kauai, where mongooses never entered, predation is less severe and the nēnēs are finally doing well. Ironically, like Canada geese on the mainland, the nēnē is fond of golf courses, demonstrating an ecological flexibility to exploit and eventually rebound in humanaltered habitats.

All approaches to recovering rare avian species and rare plants and insects on islands have similar requirements: remove nonnative plants and exotic mammalian herbivores and predators; fence off, if necessary, the critical habitat that can support the rare species; and let nature take its course. The idea is that rare native birds will respond to the positive changes under these management actions. In fact, Jack Jeffrey and his colleagues have shown that native bird numbers have increased at Hakalau Forest National Wildlife Refuge since forest restoration began twenty years ago. For example, ‘i'iwis, ‘apapanes, and Hawaii ‘amakihis have more than doubled in density. The number of breeding birds in Hakalau's open forests has increased, as shown by the Hawaii ‘elepaio (31 percent), ‘aki (125 percent), and Hawaii creeper (39 percent).

In certain cases in which a species' population has fallen below one hundred individuals, captive breeding, reintroduction, and translocation have become important tools. But all of these interventions are very expensive, and conservation in Hawaii is underfunded. The Hawaiian Islands contain about 45 percent of the endangered species in the United States but receive less than 5 percent of federal funding.

Climate change has emerged as a long-term threat to the persistence of rarities in many places we have visited, and Hawaii is no different. Besides the issue of birds moving upslope to find the microclimates they prefer, their parasites might tag along with them in a warming climate. In the 1990s, the fear was the introduction and establishment of a species of
Culex
mosquito that could survive the cool temperatures of the montane forests and spread deadly disease in the presently malaria-free zone. However, Peter Vitousek
informed me, “it's too cold for malaria to complete its life cycle in time, even though a competent vector—this new species of mosquito—is there.” But if temperatures warm up the mountainsides, the malarial parasites could survive and infect the birds that used to live above the zone.

New studies show that at least one of the native forest birds is holding its own with the local strain of avian malaria. A 2007 paper by Bethany Woodworth and colleagues documented, for the first time, that the ‘amakihi seems to be developing some resistance to malaria. Another, yet untested hypothesis is that the disease is becoming less virulent, a phenomenon of natural selection that leads some variants of the pathogen to persist and continue to infect the host. This finding was the result of a large project about ten years ago that found, quite unexpectedly, that ‘amakihis were abundant at some low-elevation sites. Before this study, the conventional wisdom was that most native birds could not really persist below the “disease line” due to avian malaria. ‘Apapanes also seem to be increasing in abundance at low elevations. The fecund ‘apapane, which can have multiple broods of two or three chicks in a season—as compared with the ‘aki, which typically has one at best—may be evolving faster to adapt to surviving the disease. Extinction may lurk in the shadow of rarity, but natural resistance to avian malaria, as is being seen in some species, gives more hope for growing resilience in others, if it is selected for soon enough. That is a lot to hope for.

On one of our last nights in Hawaii in 2001, David Wilcove and I approached the active flows of Kilauea to watch the stream of lava rolling into the sea. Under a full moon, we witnessed Kilauea in its fiery adolescence. We hopped over the black, twisted ropes of long-cooled
pāhoehoe
lava. There was nothing else—everything had been incinerated or buried in its wake. Many of the tourists scrambling about the lava field, headed for the same destination, were here for the spectacle—the sight of pieces of lava like fiery ingots dropping into a cooling sea. A few biologists were also about, snapping photographs, probably for future lectures on plant succession.
In a crack in the lava bed, the presumed lecturers gathered around a pioneer—an
‘ōhelo
, a kind of huckleberry—and nearby was a
kūkaenēnē
, whose fruit is a mainstay of the Hawaiian goose. These plants were establishing themselves in a barren landscape, giving organic life a toehold for expansion.

On volcanic islands in the species-rich tropics, a single eruption can wipe out millions of years of evolution in one moment of frenzy. But without lava flows, there would be no Hawaiian Islands. The hillside above us bore the scars of old lava streams, some ancient and long since revegetated, while others were still fresh and simmering. We have no control over the timetable for the next eruption of Kilauea, or Mauna Loa, or Mauna Kea. But we have considerable leverage over the timetable for the fate of the remaining honeycreepers, land snails, and lobelias and for the rest of wild Hawaii. It is in our hands, not just at the mercy of the gods of the mountains.

M
ANY OF THE WORLD'S
most popular wildlife viewing spots feature tame, but still rare, species that tolerate human proximity. The gray whales in Mexican lagoons, inquisitive giant tortoises on the Galápagos Islands, and habituated mountain gorillas in Rwanda are all comfortable in our presence, failing to link humans with our penchant for violence. Such innocence vanishes in the wake of war. On former human battlegrounds, wild animals flee at the snap of a twig or the first scent of any human intruder. They sink into the foliage, becoming ghosts to those who search for them. Once they have experienced the chaotic fear of war, most species retain their dread of humans even long after hostilities have ended.

Nepal has suffered from a Maoist insurgency and the battles against it, and Peru struggled through the Shining Path era. Neither, however, faced the seemingly endless conflict waged in two
other hotbeds of rarity, Vietnam and Cambodia. For a good part of the last half of the twentieth century, the forests and wildlife of Indochina endured invasion, carpet bombing, napalm, unexploded ordnance, land mines, defoliation by Agent Orange, and a heavily armed, protein-starved populace. For fifty years, naturally rare species clung where they could to survival in the midst of mayhem.

The United States' war in Vietnam ended in 1975, but the Indochina region remained closed to Western biologists for at least ten years longer. By then, the economies of Vietnam and Cambodia had begun to recover from decades of war and deprivation. But many biologists had spent the decade wondering about the fate of the irreplaceable wildlife that once flourished in the rich mountain forests, river deltas, mangroves, and coral reefs of Indochina. After the fall of the Khmer Rouge in Cambodia in 1979, was the unusual woodland wilderness east of Angkor Wat in recovery, too?

The impact of war on a fragile peninsula such as Indochina is by no means unique. Many other biologically and rarity-rich regions have suffered a similar fate. A short list includes Angola, Mozambique, South Sudan, Rwanda, the Democratic Republic of the Congo, Afghanistan, and Korea, but one could add at least twenty other examples.

This sad but all-too-common phenomenon of human conflict is the last major human-induced cause of rarity for us to examine up close. An important question to answer underpins what at times resembles a search-and-rescue mission for rarities: Do the outbreak and aftermath of war inexorably drive both rarities and some former commoners to extinction? Our first stop is an exemplary destination, the Annamite Mountains, known in Vietnamese as the Truong Son. In any language, this is one of the most biologically unexplored cordilleras on Earth, a necklace of remote ridges along the western border of Vietnam that are studded with the highest concentrations of rarities in mainland Asia. Neighbor to the Annamites are the Eastern Plains of Cambodia, a vast region bordering Laos and Vietnam, formerly home to elephants, primates, tigers,
rare giant cattle, and other large ungulates. This is a story of the rehabilitation efforts, from the early stages beginning in 1985 up through July 2012, to bring rarities back from a war-ravaged land, once peace had returned.