Paradise in peril.
As dusk descends over a black sand beach in Hawaii Volcanoes National Park, a volunteer holds a sluggish hatchling turtle in her hand while the monitoring crew logs him in. The warmth of her palm seems to animate the tiny turtle a bit, so she sets him down gently on the sand and watches him flipper his way down to the ocean. With the moon rising in the sky, the crew eventually digs 64 more little Hawaiian hawksbill turtles out of their nest, which had collapsed during a partial hatch the night before.
Those turtles don't know how lucky they are. Three years ago, before the park's new turtle crew began clearing the beach of predators, no hatchlings made it out of the nests alive. Every egg was eaten by mongooses, feral cats, and rats. Like snakes in Eden, these and other alien species are threatening to wipe out Hawaii's precious few remaining native life-forms.
Due to their geographic isolation, the Hawaiian Islands witnessed an evolution of plant and animal species found nowhere else on Earth - from birds like the shy crested honeycreeper and the gentle nene (Hawaiian goose) to plants such as the hapu'u fern and the 'ahinahina (silversword). Such species hold fascination for hikers, birders, and visitors to the Islands. And they may bear important secrets for scientists, just as the Northwest forests yielded the cancer-fighting drug taxol from the yew tree.
Their isolation has left them vulnerable, however, to aggressive competitors arriving from less-sheltered shores. Some aliens arrived by accident, such as rats on ships; others were brought in intentionally as livestock or nursery plants. Though only a small percentage have proved harmful to native species, they've wreaked havoc disproportionate to their numbers in a fragile ecosystem.
Many native species are already gone. As many as 150 bird species were once found on the Islands; today only 67 remain, and 31 of those are listed as endangered. Other animals also teeter on the brink of extinction; for example, only about 100 Hawaiian hawksbill turtle adults are estimated to remain in the wild. Plants, too, have suffered: 178 species are listed as endangered, and 28 more will soon be added to the list. In fact, Hawaii has a higher concentration of endangered plant and animal species than any other place in the United States. And at least half of the nation's documented plant and bird extinctions have occurred here.
As native species continue to decline, the battle to preserve them is being waged with a new intensity. Nowhere is the fight more intense than in Hawaii's two big national parks: the Big Island's Hawaii Volcanoes National Park and Maui's Haleakala National Park. The strategies differ, since each park faces a somewhat different gallery of rogues. But at each park, the staff is fired with the dedication of an army defending its homeland: enemy species are targeted, campaigns mapped, forces deployed. This is war.
Hawaii Volcanoes: goose versus mongoose
At 230,000 acres, Hawaii Volcanoes National Park dominates the southeast end of the Big Island, sweeping from lavabound coast to high-montane rain forest. Midway up the mountain, in the dryland forest, protection from predators plays a big role in the effort to bring back the endangered state bird, the nene. The Big Island has one of Hawaii's largest wild nene flocks, but the park's population has leveled off at about 160 birds.
To see the park's latest efforts on behalf of the goose, I drive up Chain of Craters Road. Just off the road, wildlife biologist Howard Hoshide is finishing a sort of Fort Knox for nene. Dressed in fatigues and ankle-high boots, Hoshide looks like a soldier - which, in a sense, he is. The Hawaii native has spent much of his nearly 20 years at the park defending the nene against enemy attacks.
"The nene was considered saved by some recently, since the state put 2,000 captive-reared birds back into the wild," Hoshide explains. "But once in the wild, the population crashed. We found out mongooses and feral cats were just picking off tame adults and flightless goslings."
The 7-foot-high fence he's building looks formidable and has a foot of mesh buried below and a line of barbed wire at the bottom to keep animals from sneaking underneath. Small wire traps have also been placed every 200 yards around the perimeter to deter mongooses.
Brought in from its native India in 1883 to eliminate rats in sugar cane fields (unsuccessfully, as it turned out), the mongoose has become an ecological terrorist, preying on defenseless native species from the nene to the hawksbill turtle. The park's 10-acre, open-topped nesting pen may prove to be the best answer to mongoose predation of nene. "Outside, gosling survival rate is almost nil," says Hoshide. "Inside the pen, it's 90 percent. So we know it'll work. In a way, it puts the bird back a few hundred years, to a time before Hawaii had predators."
Fencing is just part of the solution in the high-montane rain forest. Resource management specialist Larry Katahira knows this forest like his own backyard. A Hawaii native with a wiry build and a ready smile, Katahira has spent his entire 20-plus-year career at this park working on conservation issues.
Driving alongside private lands abutting the park's northeast boundary, he points out some typical problems. On one side of the road, outside the park, heavy pink vines drape over trees, choking them and all that grows underneath. Katahira explains that the vines are banana poka, first brought to the Islands as an ornamental, but now invading the wild. "It can climb to the top of the tallest native koa and 'ohi'a lehua trees - up to 200 feet. The tree dies a slow death." Birds also suffer, since the koa is home to many endangered forest birds and the red blossoms of the 'ohi'a feed others, such as the scarlet 'i'iwi and the red-and-black 'apapane.
Climbing over a short wire fence, we step into a section of the park called the 'Ola'a Forest - and seemingly back in time. Dark, viscous mud oozes over our boot tops as we clamber over roots as thick as a wrestler's arm. A soft green light filters down through the scimitar-shaped leaves of the koa trees overhead. Underneath, hapu'u tree ferns stand tall on bundles of broomsticklike aerial roots. This fern acts as a nurse log for the 'ohi'a tree, which begins on the fern as an epiphyte, then sends its roots to the ground without killing the host fern. Similar tree ferns have existed in Hawaii since the Paleozoic era, yet one particular alien species can decimate a swath of ferns and forest virtually overnight.
"The feral pig is our worst enemy here," says Katahira. "He knocks down the tree fern and chews out its starchy core heart, leaving, a watery hollow where mosquitoes breed and carry disease to native birds." Pigs also eat the fruit of the banana poka and excrete its seeds, spreading the plant deeper into the forest.
The 'Ola'a Forest today is lush and healthy because it has been fenced off and nearly pig-free long enough to prove the forest can regenerate if pigs and alien plants are removed. It contrasts sharply with decimated areas where pigs still roam, reinforcing park officials' fears of a catastrophe in the making. Studies indicate that the situation is a dire one, calling for drastic and sometimes controversial measures.
Since the start of the pig control program, park officials have fenced, trapped, and hunted the animal out of 20,000 acres, where the forest is now recovering. Each month, a ranger walks every inch of the 45 miles of pig fence and repairs breaks. Rangers have another 40,000 acres to fence, but the work is costly - as much as $50,000 per mile - and the special fund that paid for the project has run dry, putting the project's future in jeopardy.
Haleakala: fighting the black stain
The pig problem has been pretty much solved at Haleakala National Park on Maui. Fencing is nearly complete around critical sections of this complex park, whose boundaries sweep' from Haleakala's 10,023-foot summit to the sea coast and whose life zones range from the desertlike crater floor to some of the most untouched rain forest left in Hawaii.
Park officials have scored hard-won victories against voracious feral goats that once swarmed through Haleakala Crater in huge herds, stripping vegetation to the ground. Hunting of feral goats is allowed in various parts of the Islands; here, it was stepped up with the help of a large volunteer force. "The first few thousand were easy to get out," says ranger Ted Rodrigues. Eventually, only the wiliest goats in remote areas were left. "To find them, we'd release a captured goat with a radio collar. We called him the Judas goat, because he'd go join up with the wild ones and we could track them all."
The silversword, a plant that like looks like a prop from a Flintstones movie, is one species that was almost wiped out by goats and vandals. By the 1930s, only a few thousand silver-swords remained in the park. Eliminating the goats helped bring the plant's numbers back up to more than 50,000.
Recently, though, a new danger has emerged. At the edge of Haleakala's dramatic cone-pocked crater one windy morning, National Biological Survey biologist Art Medeiros enters a roped-off study site to hunt down some of the spiky plant's new adversaries. A scholarly-looking man notable (in Hawaii, anyway) for his lack of a tan, Medeiros appears eager for the pursuit, hunched over and peering intently at the ground for tracks. It doesn't take long. He spots his quarry under the first rock he overturns: a nest of reddish black Argentine ants - the same type of ant you might find in your kitchen.
"It started off slowly, with just a few colonies in the 1960s," says Medeiros. "Then they began spreading like a black stain. We started to realize that in areas with ants, we found nothing else - no native bees, wasps, flies." He explains how the survival of the silversword depends on the survival of native insects, which pollinate the plants. The ants eat the larvae of these key insects, spelling doom for the silversword, which blooms only once in its 30-year life span, then dies.
Can the black stain be halted in time? "Maybe. Ants have only recently been introduced to the 10,000-foot-level home of the silversword," says Medeiros. "We're working on a bait toxicant. It's unusual because pesticides are rarely used to protect endangered species."
Downslope from the volcano rim, another aggressive alien called the velvet tree, or miconia, is starting to invade the lowland rain forest. In Tahiti, this plant is so pervasive that Tahitians refer to it as le cancer vert (the green cancer) and have given up hope of controlling it on some islands. A few of the plants were brought to Maui by a local botanical garden in the 1970s, but their progeny quickly escaped. Now miconia spreads over 2 square miles.
Park officials and conservation officials have instituted emergency measures that they hope will stem the advance. In the first phase, they bombed miconia with spot-sprayers from helicopters. The next phase is a ground assault, pulling the plants up or shooting herbicide into their trunks with injector guns. For a long-term solution, they're looking in its original Central American habitat for creatures that attack it. This technique, called biocontrol, requires time and extensive study, but it holds the possibility for controlling many alien pests.
Hope for the future
Landmark legislation and a new program should aid the efforts to preserve native species. The goal of the Hawaii Tropical Forest Recovery Act is to provide federal funding for innovative programs to rejuvenate tropical forests. A new Alien Species Task Force will be set up to coordinate state and federal agencies' efforts to stop the flow of non-native pests into Hawaii. And by providing matching funds, the new Natural Area Partnership Program encourages private landowners to protect areas containing native species.
In the meantime, the monitoring crew guarding the Hawaiian hawksbill turtles continues to score a victory against extinction each time a nest hatches. As crew members watch the tiny black shells disappearing into the foamy surf, they may be observing the first wave of a comeback for Hawaii's rare native species.
RELATED ARTICLE: Going native in Hawaii
Visitors to Hawaii's national parks can find many ways to become acquainted with the Islands' native species. Here are some suggestions.
Hawaii Volcanoes National Park. Exhibits at the Kilauea Visitor Center illuminate conservation issues. Pick up a park map and a free Halema 'uma'u Trail brochure, which offers descriptions of native and introduced plants.
Daily ranger-led walks from the visitor center help you learn more about native species: the Summit Walk is an easy excursion into the rain forest, and the Discovery Walk is a more strenuous hike into a different native habitat each day. You can get a good park overview on your own out along the II-mile Crater Rim Drive, where you can often spot nene (don't feed the birds). Just off the road, on the 1/4-mile Thurston Lava Tube (Nahuku) Trail, you'll see a showcase of native species, including hapu'u tree ferns and forest birds like the 'apapane and 'amakihi. The Kipuka Puaulu (Bird Park) area, off the Moana Loa Strip Road, offers an easy 1.2-mile trail into a native old-growth forest with some of the largest 'ohi'a and koa trees in the Islands; the scarlet i'iwi is often among the 'ohi'a blossoms.
For a longer trek that fives you a look at native species and problem plants (Himalayan rasberry, Kahili ginger), try the 4-mile Kilauea Iki Trail.
Haleakala National Park. Entering the crater side of the park, stop in at Hosmer Grove and walk its easy self-guided nature trail. You'll get a quick education on native and introduced plants in this arboretum-like setting; you may also spot i'iwi, 'apapane, or Maui creepers.
At the small visitor center overlooking the volcano's edge, summit talks are given three times daily on native plants and animals, volcanism, and Hawaiian history and lore. Here and throughout the crater, you may see nene. Moderately strenuous guided hikes down into Haleakala Crater along 1 1/4 miles of the Sliding Sands Trail are offered twice weekly. For more of a workout, try the 3-mile guided hikes into the Nature Conservancy's rugged Waikamoi Preserve rain forest; these are offered weekly. On the Hana side of the park, the hike into Waimoku Falls is spectacular, heading up into the rain forest of the Kipahulu Valley to views of frothy falls and shimmering pools. You'll see some natives like hala and sword ferns, plus problem plants like bamboo and strawberry guava.
How not to be an invasive alien yourself. Stay on marked trails and roads, and don't bring in exotic plants or animals; clean your boots thoroughly before and after hikes to keep invasive species from spreading.
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|Title Annotation:||Hawaii's native species|
|Author:||Finnegan, Lora J.|
|Date:||Feb 1, 1995|
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