STRANGERS IN PARADISE: State Drops Acid on Coqui at Manuka, Develops New Pest Control Methods

“Given the money being spent, is that likely to have any effect at all on coqui? Will the results of that $2 million have a significant impact on coqui populations? … Is this money going down a rat hole is what I’m trying to ask.”

As chair of the state Natural Area Reserves System Commission, Dale Bonar was voicing his concerns about whether $2 million taken from the NARS fund in 2005 to control coqui frogs was well spent.

When the Legislature made the appropriation, many in the conservation community grumbled that it was a waste of money since coqui populations, at least on the Big Island, are too large and spread out to effectively control.

At the January NARS Commission meeting, Bonar and other commissioners pressed Department of Land and Natural Resources staff on whether they thought coqui control was possible and worthwhile. In short, staff explained that while $2 million isn’t likely to have a significant effect on the overall coqui problem, some of the money spent so far has led to the development of useful control methods that could be used on other species and for other things.

A Statewide Assessment

On the island of Hawai`i, where the core population of coqui covers some 8,000 acres, anecdotal evidence suggests that numbers are increasing. Although it isn’t where the coqui first arrived in Hawai`i, the island has the largest sector of the state’s horticulture industry, the main source of frogs. And with little manpower and money to control coqui, populations there “got out of hand,” Hawai`i Invasive Species Council coordinator Mindy Wilkinson explained to the NARS Commission.

Except for a handful of individual communities doing their own coqui control, there really isn’t any systematic intra-island quarantine, Wilkinson said. As a result, the frogs are spreading quickly around the island.

“Things are moving so fast. It’s coming in lumber. People are building houses and it’s showing up,” Hawai`i island NARS manager Lisa Hadway said.

According to Wilkinson, Kaua`i, Maui and O`ahu are faring a little better with fewer than 12 established populations, which for the most part have been easy to find and control. Of the three islands, Wilkinson said that Kaua`i and O`ahu are most able to successfully eradicate the frogs. Kaua`i has only one population at Lawa`i covering about 13 to 20 acres surrounding a nursery, and the Kaua`i Invasive Species Committee is working with the landowner and with $300,000 from Kaua`i County to eradicate the frogs.

O`ahu’s situation is more complicated because it has more people and more nurseries to deal with, Wilkinson said. Even so, the island is the only one to have a decent treatment facility. Waimanalo nursery owner Bill Durston, in cooperation with the state Department of Agriculture, has converted a Matson shipping container into a hot water treatment box that is successfully treating both incoming and outgoing plants, she said.

“Is it silly to have [the facility] on O`ahu and not the Big Island? Kind of,” Wilkinson said. When asked by NARS Commissioners why there aren’t more of these treatment facilities, she cited a “lack of political will and economics.” (Domingo Cravahlo, head of DOA’s quarantine branch, told the Legislature in January that his department plans to send a container to Hilo and acquire three more from Matson to be used in the next fiscal year. The DOA is also adding seven new positions to its Hilo office to help control coqui.)

Unlike Kaua`i and O`ahu, Maui is on the verge of losing its ability to eradicate its coqui population. Maui has a large one at Maliko Gulch, where the first coqui in the state was found. While invasive species workers have treated up to the edge of the gulch with pesticide, they have not yet been able to tackle the population within, which spans more than 100 acres.

“If not treated now, this year, that population is going to get away,” Wilkinson said.

NARS commissioner Patrick Conant, who represents the state Department of Agriculture on the commission, asked how the Superferry, which plans to begin shuttling people, cars and goods between islands this year, might change things.

Wilkinson said that if goods and vehicles are not subjected to some kind of inspection, the Superferry will become another pathway for invasive species such as coqui to travel between islands.

The Superferry is expected to carry 200 cars a day and there is an abundance of evidence that cars transport coqui, she said, adding that the ferry isn’t expected to start servicing the coqui-ridden Big Island until some time next year.

Wilkinson noted that the DLNR is not seeking renewed funds for coqui control and will not be testifying either in favor of or opposed to legislative proposals for funds to support coqui control this session. Still, she added, “there is a 99 percent possibility” that the Legislature will again provide funds for coqui. If that happens, she said HIISC will ask that the money come from general funds and not from the NARS fund.

In any case, she said her priorities for the coming year are to address the lack of a systematic process to control the inter-island transport of invasive species, and to “face up to the Maui situation. Face up to it or let it go.”

In the Air

Some $300,000 of the 2005 appropriation was used by the DLNR to control coqui on the Big Island. A portion of that money was used to control an isolated population of coqui at the Manuka NAR and Manuka Wayside Park.

According to Hadway, Division of Forestry and Wildlife staff first discovered coqui there in 2001. Because of the area’s isolation, she believes the frogs were purposely introduced.

“We tried our best to catch these damn things with our hands,” she says, but to no avail. A survey by Utah State University researcher Karen Beard found that the core population at Manuka spanned 24 acres (30 acres including outliers). Also, the “pretty nasty” site did not lend itself easily to ground-based control efforts, with its thick forest on `a`a lava flows and no roads, Hadley said.

“We started approaching it like a fire,” using a helicopter and a large collapsible bucket (known as a Bambi or monsoon bucket) to drizzle a citric acid mix over the site to kill the frogs, Hadway said.

After one application of the acid mix, DOFAW found a 67 to 69 percent reduction in frogs. In October 2005, staff treated about seven acres using this method and by December 2005, only one live frog was found in the treated area.

In total, DOFAW ended up treating about 12 acres at Manuka. Non-target species tests found that earthworms were also killed by the acid, but that other species were not affected. One researcher is still looking at potential impacts on the native bat.

While the method proved successful in killing the frogs, Hadway said that she and her crew were limited in the number of acres they could treat because water has to be trucked to the site and because of limited helicopter time. DOFAW has a 500,000 gallon tank, which allows for about 60 acid drops in a day. At this rate, Hadway said, she would need three weeks of helicopter time to cover the infested acreage.

Because of these limitations, she told Bonar that she didn’t know if her staff could eradicate the Manuka population within the next year.

“There’s always going to be reinfestation. We’re working on containment and reducing the core density,” she said, adding, “as long as there is an additional funding opportunity, we will try our best [to control coqui]…Without additional funding, we need to say, ‘We are going to walk away from this problem now.’…It’s a matter of priorities.”

Whether or not DOFAW’s coqui control efforts at Manuka are ultimately successful and worthwhile, NARS commissioner Lloyd Loope said he felt the development of the control method was money well spent.

“This one, to me, is right up there with the red imported fire ant. I can’t think of a worse pest,” says NARS Commissioner Lloyd Loope.

To everyone who has mourned the recent loss of countless wiliwili trees to the invasive erythrina gall wasp, which swept through the state like a wildfire, Loope says that is nothing compared to what a new strain of the rust known as Puccina psidii could do to our `ohi`a trees, which are the most dominant species in native Hawaiian forests.

While this `ohi`a rust has already been found in Hawai`i on both `ohi`a and rose apple, Loope worries that the continued importation of Myrtaceae (the family of plants that include `ohi`a, guava and eucalyptus) will bring in a strain that could knock our forests dead.

Last year, prompted by Loope and the NARS Commission, DLNR director Peter Young sent a letter to the state Department of Agriculture asking it to immediately halt the importation of Myrtaceae. In 2005, the DOA issued a new pest advisory on the rust encouraging people not to transport any Myrtaceae between islands. A few months after the letter from Young, at the request of the DOA’s plant quarantine branch, Loope said he put together a rule package to address the rust threat. Rules were drafted and were making their way through the public and agency review process, but were stuck behind a long queue of rules for other things, he said.

In the meantime, in December on Maui, quarantine officials intercepted a rust-infected plant from California. Before then, officials assumed that the rust would come from plants from Florida or Brazil, Loope said.

Because the rust is now even closer to home, Loope again raised the issue of asking the DOA to implement emergency rules prohibiting the importation of Myrtaceae. At its January meeting, the commission again discussed how to get the DOA to take immediate action against the importation of this pest and decided that this time they would recommend that Peter Young speak in person with DOA director Sandra Kunimoto about the problem, since there never was a response to his letter.

Commissioner Flint Hughes noted, “This is like the gall wasp, but the difference is we didn’t know about the gall wasp coming. We know [the rust] is. If we don’t do anything, it’s our fault.”

Commissioner Pat Conant also noted that the DOA’s mandate includes the protection of both crops and forests.

If a destructive strain does arrive and starts attacking `ohi`a, Loope said the watershed partnerships, which receive millions of dollars of public and private funds to protect natural areas statewide, will go out of business.

“Some people may say, ‘Lloyd, you’re over-reacting.’…[But] internationally, this is the biggest threat to eucalyptus in the world,” he said.

To give his ears a break, as well as those of his helicopter pilot, Maui Natural Area Reserves manager Bill Evanson bought a silencer for his rifle, which he used during aerial shooting missions of feral cattle and goats on state conservation lands.

When he went to the police station to register the silencer, however, he inadvertently brought the state’s aerial shooting program to a halt. Silencers are illegal under state law. And so are high-capacity ammunition magazines, which Evanson had bought, as well.

The silencer incident, Evanson says, grounded the state’s efforts to reduce populations of ungulates through helicopter shoots in 2003. Since then, the DLNR has revised its firearms, aerial shooting, and helicopter policies. On December 8, the Board of Land and Natural Resources approved the revisions, despite the strong objections of animal rights activists.

Under the new policies, DOFAW employees are exempt from both state and federal regulations (as federal rules permit). In no case, though, are silencers allowed for aerial shooting.

“Because the use of firearms, aerial shooting, and the use of helicopters come with inherent risks, the Department has adopted policies regarding their use,” a report to the Land Board by DOFAW administrator Paul Conry states, adding, “The specific issues identified for review were compliance with state and federal firearms laws and regulations, use of specialized equipment, and worker and public safety considerations (including training).”

The new policies require gunners to have a background check and to have received firearms training from both the state and federal governments. Flight plans must be approved and aerial control trip reports must be submitted within 48 hours of completing a mission. Firearms may be used to control rats, mongoose, feral dogs, feral cats, nuisance birds, rabbits, snakes, and feral pigs, sheep, goats, mouflon sheep, cattle, and deer, among other things.

While he feels the policies still need some tweaking, Evanson says he is preparing aerial plans and hopes to go on an aerial shoot within the next six months.

The state’s practice of aerial shooting began in the 1980s when a federal court order (Palila v. Department of Land and Natural Resources) required the state to remove mouflon sheep from Mauna Kea, which were eating mamane trees that provided habitat for endangered palila birds. Since then, the practice has been used to control cattle in West Maui and goats on Moloka`i.

In the mid-1990s, opposition from the animal rights activists and hunters halted aerial shooting for a while, Evanson says, but it resumed in the late 1990s and continued until DOFAW decided to revise its policies and procedures in 2003.

At the Land Board’s December meeting, animal rights activists again protested the use of firearms to kill feral animals. “Where is the message, ‘thou shalt not kill?’ Where is the aloha spirit?” Wayne Johnson of Animal Rights Hawai`i asked the Land Board. Johnson said that the Mauna Kea court order doesn’t require the state to shoot sheep, but only to control them, and urged the state to invest in birth control for the animals or try translocating them.

In written testimony submitted to the Land Board, Cathy Goeggel, director of Animal Rights Hawai`i, argued that aerial shooting is inhumane and inaccurate, and also urged the board to support non-lethal animal control.

“Wounded animals can suffer for hours, even days before perishing. A ‘clean kill’ cannot be guaranteed,” she stated in her testimony. She added that from 1993 to 2006, aerial shooting by the U.S. Department of Agriculture’s Wildlife Services “encountered 24 accidents with 32 injuries/fatalities on the mainland. Costs included NTSB and FAA investigations as well as payouts to survivors and families of fatalities. Does the State of Hawai`i really want to put the taxpayers at risk for a program whose potential costs far outweigh any possible habitat protection?”

In contrast, Ed Misaki, director of The Nature Conservancy’s Moloka`i programs, urged the Land Board to adopt the new policies, which would allow aerial shooting to resume on his island.

“The lack of aerial shooting has affected the conservation landscape of both the North Shore valleys and cliffs, and the South Slope and its associated fringing reef system,” he told the board, adding, “The [East Moloka`i Watershed Partnership] is ready and waiting to conduct aerial shooting. Funding is in place. DLNR aerial shooters are trained. Helicopter pilots are familiar with the Moloka`i conservation areas, trained in aerial shooting, willing and available…. The local Moloka`i community wants their watersheds protected from the destructive goat populations. They are tired of seeing the denuded landscape and the resulting sedimentation of their fringing reef.”

Pacific Science, the quarterly journal published by the University of Hawai`i, has launched a new series, “Biology and the Impacts of Pacific Island Invasive Species.” The series, edited by David Clements of Trinity Western University in British Columbia, debuted in the January 2007 issue (Volume 61, Number 1).

Warren S.T. Hays and Sheila Conant, both professors at the University of Hawai`i, co-authored the inaugural study, a global overview of the impacts of mongoose on island ecosystems. Their findings suggest that mongoose, though widely blamed for extinctions of ground-nesting birds, is in fact responsible for the extinctions of just three vertebrate species – the barred-wing rail, the Jamaica petrel, and the Hispaniola racer (“and in each of those cases, there is room for doubt,” the authors add).

“The degree to which mongooses are responsible for the historical decline of bird species is often hard to assess,” the authors write, “because of exacerbating factors such as introduction of rats, cats, dogs, and pigs, and habitat encroachment by human communities. It must be noted that any bird species now living in the presence of mongoose populations in Hawai`i has been doing so for over a century. It has been suggested that ground-nesting bird populations have established a predator-prey equilibrium with mongooses in the Caribbean… This may also be true in Hawai`i, though it is surely also true that the mongoose’s presence poses a substantial barrier to reestablishment of ground-nesting bird populations in their historical ranges.”

Hays and Conant discount the “common story in Hawai`i that small Indian mongooses failed to control rats in areas of introduction because the mongoose is diurnal and rats are primarily nocturnal…. Most published accounts dispute this story, asserting that the small Indian mongoose served as an excellent cane-field ratter…, though it was eventually made obsolete by the development of improved techniques of rat poisoning.”

The idea that wild mongooses and feral cats might compete for food also is challenged. “Feral cats and wild mongooses peacefully share food at artificial feeding sites on O`ahu, feeding within centimeters of each other,” the authors write. On June 3, 1999, Hays “observed two large male mongooses pass together within 3 m[eters] of an adult feral cat, in a relatively undisturbed woodlot and apparently by coincidence, without any of the animals involved showing any sign of excitement or stress even while making eye contact.”

— Patricia Tummons

Volume 17, Number 9 March 2007