Thursday, November 13, 2008

Hawai'i'is BioInvasion III: Pu'u Wa'awa'a and the Ungulate Alliances

(This series first appeared in HIJ in 2001)

To understand the battle over Pu`u Wa`awa`a, one might find it useful to understand the tumblebug.

Tumblebugs, also called scarabs or dung beetles, raise their larvae in cattle dung, which they cut from fresh cow patties and shape into small, very-nearly-perfect spheres. They can often be seen at work in this island’s upland pastures—one beetle beneath the ball, kicking, and another riding atop it like a circus acrobat—rolling their prize precariously off to some scarab hatchery site.

Tumblebugs aren’t native to Hawai`i, and no one knows how they got here, but it’s quite obvious why they’re here. Tumblebugs are evolved to go with grazing animals. They help disperse cattle manure, which feeds the grass that the cattle eat. They’re part of a vast and powerful coalition of creatures: the rangeland ecosystem. They’re here because they’re useful to the other members of this coalition, and the other creatures are useful to them.

Of over 4,000 alien species introduced to the Hawaiian Islands since the coming of humans, the vast majority probably are here because another species—usually humans—found them useful, or at least decorative. They formed alliances.

But sometimes alliances shift. Once here, species from chameleons to kahili ginger have quickly found that they didn’t need us anymore, and we found that we didn’t need so many of them. But it’s almost impossible to find a species that some human doesn’t still value. Even campaigns to control coqui frogs and miconia have met with opposition.

Nowhere is this conflict clearer than when ungulates—hooved animals—are involved. Ever since Hawaiians arrived with pigs in their sailing canoes, ungulates have thrived on this island with the active aid of human beings. And the animals themselves have found other allies. Guava, for instance, found feral pigs even more useful than humans for disseminating their seed over huge areas. With guavas and a huge array of other foods available, pigs don’t particularly need humans, though some humans have continued to find pigs useful.

But native Hawaiian ecosystems had evolved without grazing animals, and weren’t prepared to fend off those devastating coalitions. Huge areas of the island have been transformed from native forests into rangeland, and some of the remaining forests have been ravaged by overpopulations of pigs and pig-assisted plant invaders. People who found the native forests pleasing and useful began forming alliances to save it. And the human allies of pigs and cattle and sheep felt threatened.

Coalitions Collide at Pu'u Wa'awa'a

Which brings us to Pu`u Wa`awa`a, a huge tract of state-controlled land in North Kona above Kiholo. For decades, much of the area has been leased as ranch land. But it also holds, by some counts, at least 22 endangered plant and animal species.

On Friday, November 16, the State Board of Land and Natural Resources heard arguments for two competing management plans for Pu`u Wa`awa`a Ranch. One plan was put forth by a Ka`Ahahui o Pu`u Wa`awa`a, a non-profit formed by a coalition of conservationist and native Hawaiian groups, including The Nature Conservancy of Hawai‘i, Hui`Ohana Mai Pu`uanahulu a me Pu`u Wa`awa`a, Tropical Reforestation and Ecosystem Education Center (TREE), and the Hawai‘i Ecosystems Project of the U.S. Forest Service and Stanford University. In testimony, the proposal also got backing from a roll call of environmental organizations, including the state and local Sierra Club, as well as several wildlife biologists and members of some kama`aina and native Hawaiian families who had been working with the Ka `Alahui in the project’s planning stage.

The competing proposal was advanced by a group called the Wildlife Conservation Association of Hawaii (WCAOH), whose “cooperating organizations” include current leaseholder Pu`uwa`awa`a Cattle Company as well as Summit Hawaii, Inc. (a public relations firm), Pig Hunters of Hawaii, Big Island Bird Hunters, the Hualalai Archery Club and the Volcano Chapter of the National Wild Turkey Federation. Nearly all of the testimony in support of the WCOAH plan came from ranchers and hunters.

Both groups claim to be conservationists. Both would encourage game hunting as a “management tool” and allow continued ranching on the property. But the two plans also differ substantially, both in philosophy and in practice. Ka `Ahahui o Pu`uwa`awa`a’s plan would attempt to reinstate ahupua`a management—the traditional Hawaiian style of land use, which takes a roughly pie-piece shaped slice of the island and manages upland, lowland and ocean resources as an interactive whole. The plan would strongly encourage ecotourism and educational uses, and would emphasize large-scale restoration of native forests. The WCAOH seeks only the upland section of the property, where ranching is viable, and would subcontract the management of the parcel back to the Pu`uwa`awa`a Cattle Company. .

The Ka `Alahui plan would cut the cattle herd approximately in half, and attempt to fence some critical habitat. The WCAOH plan would maintain a larger herd.

Integral to the two groups’ plans are very different views on the roll of hooved animals in the land’s health. One group essentially views ungulates as a major part of the problem. The other portrays them as a major part of the solution.

The Fire Fight

Ka `Alahui’s plan seems to reflect a philosophy similar to those practiced in Hawai`i Volcanoes National Park and the Hakalau National Forest Bird Sanctuary. Though it recognizes the value of cattle in controlling some invasive plant species, and even in reducing the amount of grass for fire control purposes, it essentially regards the coalition of grazers and grass as alien invaders.

“Extensive areas of dry and mesic forests have been altered by human activity all around the state and the world,” the proposal states. “The combination of ungulate grazing, grass invasion, and fire poses a triple threat to these areas; forests will not recover while they are being grazed at commercially viable rates, but the removal of grazing allows grass biomass to accumulate and greatly enhances the likelihood and severity of fire. Fire in turn further encourages grass growth and can inhibit forest regrowth. Grazing/grass/fire interaction is a globally significant threat to biological diversity, and it represents the most substantial challenge to the restoration of Hawaiian forests.”

The WCAOH plan, on the other hand, sees cattle and sheep as essential to fire control.

“We are...acutely aware that if the ranching partners who know this land so well are unable to maintain a viable operation, all the other goals may fail due to lack of well-managed fire control through grazing,” the plan maintains. “Grazing is well recognized by laymen and scientific individuals alike as the primary means of fire control in a very dry area such as this.”

But some biologists question whether ungulates actually work for fire control—and point out that deforestation for pastureland may be one reason the land is drying out.

Among them are Jim Jacobi and Rick Warshauer of the U.S. Geological Survey’s National Biological Service, whose studies provide data that state and federal agencies use for wildlife management.

“Ungulates have caused the reduction and elimination of native woody and herbaceous vegetation, which result in the drying of the landscape and the spread of alien grasses, both of which foster fire,” maintains Warshauer.

Jacobi agrees: He notes that fires are more common in grasslands than in forests, because forests retain more moisture and shade out flammable grass species. Grazing doesn’t prevent fires, he believes, “unless the ungulates have reduced it down to dust, pretty much, and that’s not good grazing.”

He cites a recent fire at Pu`u Loa, on the southeast side of Mauna Kea, as an example.

“This was an area that was heavily grazed down to very short grass,” he notes. “It [the fire] carried even on the places that it was basically eaten really down to nothing.... The problem is, dry areas will burn. The solution is to reduce the opportunities for fires to start and to have the means to put them out quickly.”

The WCAOH cites past fire history, including a fire in an area called the Kiholo-3 paddock, which was kept free of cattle for six years. “Then a fire reached the area and destroyed it so any restoration was in vain,” states the proposal.

But biologists note that forest restoration requires a much longer time frame than six years, especially in dry areas where trees grow slowly.

“It’s a fiction,” says Warshauer, of the idea works as a method of fire control. “It’s often used to justify grazing where alternative land uses have been proposed.”

Different Ungulates, Different Roles

Pu‘u Wa‘awa‘a is a near-perfect microcosm of larger battle over ungulates that is going on all over the island. The parcel holds all three of the most common ungulates: sheep, cattle and pigs. In their normal habitats, each plays occupies a different niche. Cattle normally subsist mainly on grass. Sheep are browsers that often serve as the shock troops for advancing rangeland, by clearing brush and trees that would otherwise shade out the grasses. Pigs are omnivorous grubbers, rooting through the soil for roots and worms, but also opportunistically eating just about anything else that comes their way.

Environmentalists say evidence is overwhelming that all three ungulates contribute heavily to the decline of native forests. But some hunters and ranchers claim differently.

“Basically, there’s a preservation environmental side that says all ungulates are alien species and should be eradicated,” says hunting advocate Bob Duerr. But he notes a lack of studies on the possible benefits that game animals cause for the local environment. “The problem’s not a public wildlife official...who says, ‘Hey, you know what? Let’s take a scientific peer review, and let’s take a look at the positive aspects of pigs in the forest.”

When questioned, wildlife managers and biologists often say that they’re happy to listen to hunters, and value hunters’ experience with the land. The problem is that some the hunters’ claims just don’t seem to match the data already coming in from the field.

Sheep vs. Mamane

For instance, feral sheep and Mouflon sheep—and hybrids, since the two interbreed freely—have long been attacked by conservationists, especially for the damage they have done to upland dry forests such as the mamane forests of Mauna Kea. Since the late 1970s, under a court order obtained by conservation groups, the Department of Land and Natural Resources’ Division of Forestry and Wildlife (DOFAW) as mounted a so-far-unsuccessful effort to eradicate feral sheep on Mauna Kea.

“They’ve shot most of the animals they’ve seen. But twice a year, they go out and shoot similar numbers to what they shot before,” observes NBS biologist Paul Banko, who studies populations of palila, an endangered bird that feeds mainly on mamane seeds in the upland dry forests. He admits that his studies aren’t designed to document the damage that the sheep have been doing to the mamane forest, because “their effects on the habitat has been thoroughly documented for years.”

But WCOAH founder Lloyd Case claims disagrees with that conventional wisdom. “It’s all documented that palila use the wool from the sheep to line their nest,” he notes, for example. “No there’s no more sheep, so more of the young birds will die.”

Warshauer and Jacobi scoff at the notion that sheep are vital to palila fledglings: “What did they do before the sheep got there?” asks Warshauer.

“Naturally they [palila] use lichens,” says Jacobi. “In all the nest studies, there’s been a very limited use of sheep wool. It’s a not a major component of the nest.”

Case also maintains that the sheep benefit the mamane by pruning them back. “If the sheep browse them and keep them clean, you get better growth,” he maintains. “The mamane seeds stick in the wool and they spread them around.”

The biologists shake their heads at that claim. To them, it contradicts not only overwhelming evidence on the ground, but also the vast weight of evolutionary history. “Grazing by ungulates is really a severe trauma,” says Warshauer. “The native plants evolved in the absence of anything larger than a few flightless birds.”

Biologists note the structure of grass, for instance, which evolved under the constant pressure of grazing animals. The stems are jointed, so the tops break off before the plant is pulled up by the roots. The roots form a tough, dense, interlocking mat, so they’re hard to pull up. Many grasses spread by runners when grazers are present; when the herds are away, they take advantage of that absence to send up seed heads with millions of seeds, designed to stick to the grazer’s hair and “hitchhike” when the grazers return.

Native plants, which evolved without plant-eating mammals, lack these adaptations. They have no thorns, no chemicals that make them taste bad. When cattle and sheep were introduced, they ate the local plants like ice cream. The result was natural selection in favor of the grazing-adapted invaders. In many places, the only survivors were mature trees whose whose branches grew out of reach. Smaller trees such as mamane (Sophora Chrysophylla) were especially hard-hit.

After DOFAW began sheep eradication on Mauna Kea, scientists such as Banko and Jabobi saw signs that the mamane forest was starting to recover. Banko notes that in the upland Mauna Kea Forest Reserve now, “About one of three mamane trees is less than 20 years old. That’s actually a fairly significant response of the forest.”

Case maintains that the explosive growth of grass in turn provides excellent cover for rats, which eat bird eggs and nestlings. But the wildife researchers argue that all three invaders—rats, grass, and ungulates, are problems must be dealt with, piece by piece.

“It’s hard for me to imagine that the best solution is to bring back the original problem,” says Banko.

The Bond Between Hunter and Hunted

An even more emotional issue than cattle and sheep are feral pigs. The handbook Hawai’i’s Invasive Species calls pigs “the number one economic threat to watersheds, damaging the islands’ freshwater sources.” In addition to spreading weed species; pigs root up native vegetation and hollow out fern logs, creating places where water can collect and breed avian-malaria-carrying mosquitoes.

Despite all this, some hunters claim they’re good for the forest.

Case maintains that where he finds the most birds is also where he finds the most pigs. “They (scientists) don’t realize that the more you kill our animals, the more the birds move,” he claims. “They get their minerals and stuff from the ground. The pigs root the ground up for them.”

But biologists point out, again, that native birds somehow solved the problem of getting minerals long before the first pigs arrived with the Polynesians. And they point to dramatic recovery of the forest undergrowth in areas where fences have been fenced out—the rainforest around Thurston Lava Tube in Hawaii Volcanoes National Park, for instance.

They also note the pigs’ potential for explosive population growth. Where reproduction is concerned, pigs are more like rodents than other ungulates. Each sow is capable of suckling up to twelve piglets at a time, which means that without considerable hunting pressure, a forest can be rapidly overrun.

Complicating the issue of pig control are some very deep emotional bonds. Pigs are entwined in native Hawaiian mythology; a pig god was both Madame Pele’s consort and chief rival. For native Hawaiian culture, pigs were the only ungulate, a vital source of animal meat in a protein-scarce environment.

For some local hunters, they still are.

“When our economy goes down, we live off the land,” maintains Case. “And now, more than ever, we turn back to the land. These animals right now are worth more to us. They’re our money in the bank.... When I never had [a] job, these animals fed my family.”

Decisions for the Top Predators

That history was very much in the minds of hunters and ranchers at the November 16 hearing. They repeatedly testified about the importance of preserving “our way of life.” But Ka `Ahahui supporters countered that many of their members were also from kama`aina families—and that for generations, ranchers and hunters had been virtually the sole users of much of the ahupua`a, and that for most of that period, the forest had degraded.

A DOFAW staff report recommended that the Ka `Ahahui proposal be adopted, with some changes—partly because Ka `Ahahui already had considerable grant funding in place. But after a day of testimony and two failed amendments, the Board adjourned without a resolution on the issue—sending both sides back to beef up their plans for another round.

But what both sides, and all island residents, will also have to cope with is the essential imbalance that humans and their biological allies have created. The range ecosystem and the pigs are designed to be kept in check by predators such as wolf packs and mountain lions. Without a top predator, the ungulate populations run amok. Without ungulates, the grasses run amok. The only top predator on this island is us. Until humans figure out how to responsibly manage that role—whether by hunting or by other means—Hawai`i’s landscape will remain explosively unstable.

No comments: