Buildup in Guam, Cuts in Inspections
Increase Brown Tree Snake Risk Here
“About a dozen species of native forest birds were present and in stable populations” when the brown tree snake (Boiga irregularis) arrived in Guam in the late 1940s, said James Stanford of the U.S. Geological Survey and a member of the brown tree snake rapid response team based on Guam.
“Just two species of native birds are still hanging on in very reduced numbers.”
Guam “lost native lizards and bats. The economy was devasted. Forests are showing the effects, since we no longer have seed dispersers. Forests are not regenerating because we lost a link in the chain there. It’s just snowballing. Guam is in a terrible mess because of this snake,” he said.
While people in Guam would like to see the snake eradicated, he told the audience at the Hawai`i Conservation Conference last month, “the most pressing need is management of the Guam snake population, keeping it from spreading.”
The snake population on Guam, Stanford said, ranges between one million and two million animals. Keeping it contained on Guam has been a challenge up to now, but recent developments make the task all the more daunting.
Increasing the possibility that the snake might be carried elsewhere are activities related to the U.S. military buildup in the Commonwealth of the Northern Mariana Islands and Guam. For Rota, Tinian, Saipan, and some far northern Mariana islands, “there’s a super-high critical risk,” Stanford said. The buildup also adds to the risk that the snake might end up in Hawai`i or other Pacific islands. “Early detection and rapid response capacities are not keeping pace with these issues,” he said.
Pre-departure screening of planes and cargo has been ongoing for years. Despite that, brown tree snakes have made it to Hawai`i, alive, on numerous occasions, he said; “we think they’ve all been captured.” If the snake were to become established in Hawai`i, “you’d see the exact same impacts here as on Guam, but on a larger scale. If Hawai`i had the snake established, you’d become a pariah, just like Guam. It would also put the U.S. mainland at greater risk.”
Yet the future of the U.S. Department of Agriculture’s APHIS (Animal and Plant Health Inspection Service) program in both Guam and Hawai`i is uncertain, Stanford said. “Will brown tree snake control activities on Guam continue during fiscal year 2012? If not, Guam’s trade partners should anticipate an increase in snake arrivals,” he said. (Last month, the Department of Interior approved an agreement between the Office of Insular Affairs and the U.S. Geological Survey, calling for $1.213 million to be used by the USGS to continue developing and testing tools for capture and control of the snake on Guam.)
On average, the current program removes between 200 and 300 snakes every week from cargo boxes leaving Guam. “Are Hawai`i’s early detection and rapid response capabilities sufficient” to address the possible reduction in Guam screening? Stanford asked.
Several people from Hawai`i have been trained in Guam to respond to possible snake sightings, but Stanford emphasized the need for increased capability in this area. The snake “is a living organism that moves about quite regularly,” he said. “If people report they’ve seen a snake and they’re waiting two days for me to arrive, we’re not going to get many. But if we have people in-house, and can get them out there in 15 minutes or half an hour, we’ll have a better chance of success.”
In other Pacific islands – the Federated States of Micronesia, Palau, Fiji – “we’re much further behind,” Stanford said. “We have a few trained responders here and there, but resources are very limited.”
Stanford’s team has set up an “alien snake hotline:” 671-777-HISS (4477). “We get on average about 45 calls per year regarding non-native snakes,” he said, including several calls from the U.S. mainland. “We got one from Tulsa in 2010, another May 19, 2011, again near Tulsa.”
For the most part, the hotline is not for residents of Guam, given how ubiquitous the snake is there. But if they see another type of snake, they should definitely call, he said. “We got a call last year from Guam for a non-brown tree snake… Turned out, it was a Honduran milk snake, probably brought illegally to the island as a pet.”
The brown tree snake on Guam “wiped out birds, lizards, and one bat species. It eliminated the poultry business. Small pets, cats, dogs, puppies – gone…. For a while, people thought snakes would eat through everything, and the population would then decline, but we’ve got so many other non-native species that are now supporting them,” Stanford said. “They’re now eating a skink from the brown tree snake’s native range. It’s extremely plentiful, so there’s no problem with high predation. As long as we have that skink, the snakes are going to be fine.”
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`Amakihi Face New Threat in Mange
“I work with train wrecks, so don’t expect any cute pictures.”
The audience was thus duly warned by Dennis LaPointe, a researcher with the U.S. Geological Survey’s Pacific Island Ecosystems Research Center, but that hardly prepared it for the gruesome photos that he proceeded to display on the large screen in the conference room. One picture after another showed beautiful `amakihi (Hemignathus virens) beset by horrible, scaly growths on their feet, caused by a mite, Knemidokoptes jamaicensis, also known as the scaly-leg mite.
The affected `amakihi were found in 2007, when Jacqueline Gaudioso, a graduate student at the University of Hawai`i-Hilo studying plumage coloration, mist-netted a couple of birds with “peculiar lesions,” LaPointe said. She brought them to the USGS researchers, who proceeded to inform Gaudioso that she had discovered the first case of knemidokoptic mange in Hawai`i. Further surveys found the mite was present at sites from 300 meters in elevation to 600 meters, with the highest densities at the highest elevations.
After that, LaPointe said, he and his colleagues “decided to get some of these birds into the aviary and see what’s happening as a consequence.” Infested birds were taken from Manuka, and clean ones were collected from the Upper Waiakea Forest Reserve.
Over the next 16 months, they tried to discover how the mite was transmitted, but they did not succeed in infecting the clean birds. “As we progressed, we didn’t see anything looking like transmission,” LaPointe said. “Maybe it occurred, but there were no clinical signs.”
What researchers were able to do was observe the progression of mange in the affected birds. “In one case,” he said, “an advanced infestation seemed to resolve itself. Birds start to peck at the lesions, preening them off, but it depends on the individual bird. Another case was the complete opposite: the bird came in with advanced lesions, and the lesions continued to grow. Then there was a drastic drop in lesion size, and a lot of necrotic tissue. Six months out, the bird died.”
In a third case, the bird came in with “early stage” infestation. “Over time, it seems to have resolved the lesions,” LaPointe said. “Then the lesions started growing… We treated the bird with Moxidectin [used to treat mange]. Shortly after the treatment, the lesions started to resolve rapidly…. Moxidectin speeds up the recovery process.”
Three of the captive birds died, allowing LaPointe and his colleagues to speculate on the cause of death. “The intermediate and advanced lesions predispose the birds’ feet to injury and secondary infection, but we don’t know what happens in the wild,” LaPointe said. Very large lesions on the feet may interfere with the birds’ ability to perch or constrict blood flow, leading to necrosis, but, he added, s
econdary infections are the most likely cause of death.
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Hunting of Game Mammals Gets
Little Public Support in Surveys
Cheryl Lohr, a graduate student in the University of Hawai`i’s Department of Natural Resources and Environmental Management, has been surveying a number of groups to get an idea of public support for hunting of game mammals and game birds in Hawai`i. She presented her preliminary results in a conference poster exhibited.
Lohr and her professor, Christopher Lepczyk, sent questionnaires to hunters, “conservation professionals,” members of the Hawaiian Civic Clubs, farmers, animal welfare advocates, and “random residents.” Questions were intended to gauge the degree to which a given group would tolerate game animals in their environment and how the respondents would like to see those animals be managed.
At the conference, Lohr had results for four game species: axis deer, goats, mouflon sheep, and pigs. She had sent surveys to more than 5,300 residents in the various groups, more than half of them in the “random resident” class. More than 1,600 hunters received questionnaires, as did 643 “conservation professionals,” 49 Civic Club members, 339 farmers or other agriculturalist, and 254 animal welfare advocates. The highest response rate (37 percent) came from animal welfare advocates. Thirty-three percent of conservation professionals returned their surveys; 32 percent of agriculturalists; 29 percent of Civic Club members; 10 percent of the random residents; and just 9 percent of hunters.
Among all the groups, Lohr found, the hunters were alone in wanting to see an increase in game abundance. When Lohr attempted to measure the potential for conflict among the various groups, she found that the greatest potential area of dispute concerned management of axis deer and mouflon, with hunters wanting to see increased populations of both animals (as well as pigs and goats), and practically everyone else wanting to see those populations reduced. With respect to goats and pigs, on the other hand, the potential for conflict was less pronounced.
Lohr hopes to follow up with further analysis of her results, hoping to weigh how important the animals are economically and culturally, the degree to which people derive enjoyment from knowing they are present in the wild, how much damage they inflict on property or income, the extent to which they pose a health and safety risk for humans and other wildlife and native plants, and how they affect water quality and soil.
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The Threat from Above: Peregrine Falcons at Midway
Pity the poor Laysan duck. With its sole population at Laysan Island subject to being wiped out in a single catastrophic event, the Fish and Wildlife Service shipped some of them off to Midway Atoll to start a new population. As Andrew McClung of the U.S. Geological Survey’s Pacific Island Ecosystems Research Center noted in a poster at the conference, the ducks were easy pickings for a vagrant peregrine falcon in 2006 and again in 2008. In those years, 4 percent and 2 percent, respectively, of the Laysan duck population were killed by raptor predation. Other seabirds were taken as well, including black noddies, brown noddies, bonin petrels, Tristram’s storm-petrels, ruddy turnstones, Pacific golden plovers, and white terns.
Their carcasses were all found on the tarmac at Midway.
McClung concludes that if the abandoned airstrips at Midway were revegetated, the birds might have greater cover against the falcons. Otherwise, “vagrant Peregrine falcons overwintering on small islands could exert adverse effects on populations of endangered birds, with greater risk of significant impact for newly translocated populations.”
The Laysan finches that were transplanted to Midway fared better, with no documented falcon kills. Those that remained behind on Laysan, however, were hit hard by visiting Peregrine falcons in 2008, with at least 80 finches killed (as well as numerous seabirds).
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Slug Poison Boosts Rare Plant Survival
Move over Guinness. Sluggo is now the most effective slug killer in Hawaiian forests, thanks to the O`ahu Army Natural Resource Program (OANRP).
For years, beer traps and copper barriers were the best available methods to keep slugs from munching rare native plants in the wild. And although tests revealed that dark beer captured four times as many slugs as Coors Light, beer alone could not tackle the slug problem.
But late in 2010, after several years of working with state and federal agencies, the OANRP won approval from the Hawai`i Department of Agriculture for a Special Local Needs label for Sluggo, an organic iron phosphate-based pesticide that kills slugs upon ingestion.
“This label means that, for the first time, eradication of slugs in a natural area is possible,” wrote the OANRP’s Stephanie Joe in her abstract for last month’s conference.
Introduced slugs (there are no native ones) threaten 59 of Hawai`i’s 273 threatened or endangered plant species, Joe said in her presentation. In particular, slugs attack two critically endangered species — Cyanea superba and Schiedea obovata — that the Army must manage and stabilize if it is to continue training in Makua Valley.
“Slugs alone can affect your outplanting success,” Joe said.
So a few years ago, the OANRP began testing Sluggo in the Army’s 36.5-hectare Kahanahaiki Management Unit in the Wai`anae mountain range. In addition to testing the pesticide’s efficacy against slugs in montane and mesic areas, the Army also studied whether it harmed native snails.
Joe found that while Sluggo did not eradicate the slugs, it caused a four-fold decrease in their numbers in treated plots and did not significantly affect native snail populations. (The Army must also stabilize two species of rare Hawaiian snails.)
Other tests found that Sluggo can improve plant survival. Twice as many Cyanea superba plants survived in slug-free areas six months after application than in untreated areas. In fact, Cyanea survival in areas without slugs was so robust it equalled that of the invasive weed, Clidemia hirta, Joe found. She also discovered that Sluggo had a significant positive impact on Schiedea obovata seedling emergence.
While Sluggo appears to be an important tool for rare plant recovery, it cannot be applied if native snails are present, she stressed.
“To ensure native snails are not impacted, make sure slugs really are the problem and have an experienced malacologist survey the area,” Joe said, adding that Sluggo can’t be applied within 20 meters of any tree containing Achatinella snails.
For now, the Army is doing targeted application around plants during the wet season and fruiting seasons, she said. It’s also footing the bill — $3,500 a year — for the label, which is good until 2015.
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Rare Plant Recovery: A Landowner’s Perspective
“There is no better way to dissuade a landowner from [doing conservation work] than to stick them with the responsibility of getting a bunch of permits and doing public hearings,” said Stephanie Dunbar Co in her conference presentation on rare plant recovery from a landowner’s perspective.
Permitting and hearings should be taken care of by government agencies, said Co, a botanist and daughter of Kip Dunbar, who owns Molokai’s 1,100-acre Kainalu Ranch. The ranch has received various state and federal grants over the years to protect its agricultural and natural resources.
“Accounting for approximately 50 percent of Hawai`i’s total land area, private lands are critical components to successful restoration efforts th
roughout all available remaining habitats,” Co’s conference abstract states.
With a grant from the state Department of Land and Natural Resources’ Division of Forestry and Wildlife, Kainalu Ranch has been able to keep the palm Pritchardia munroi, also known as lo`ulu, and the tree Cyanea dunbariae, a.k.a. haha, from going extinct in the wild.
“[Pritchardia munroi] is a species near and dear to my family,” Co said, noting that it was named after her uncle James Munro, “who was really good friends with [famed botanist] Joseph Rock.”
With a single individual left in the wild, the ranch successfully outplanted 30 more about six years ago, she said.
Cyanea dunbariae, named after her great-grandmother, who showed it to Rock, has only eight adult individuals left in the wild, she said. Her family planned to plant 12 more last month.
With a 2002 grant, the ranch also fenced its upland pasture and planted five acres with 1,000 koa and 500 koai`a to see if they held any forestry potential.
“They’ve both done well,” she said, adding that the ranch’s conservation work has been “hugely satisfying.”
“Given my family’s fine ancestry, we’re really concerned with conserving things that are Hawaiian,” she said, adding that “everybody needs to do their part.”
While her family has strong personal reasons to preserve rare native plants, “rarely does rare plant recovery work positively affect a landowner’s bottom line,” she said.
Establishing a baseline for threatened and endangered plants, excessive permitting, excessive public meetings, providing access, the lack of technical and/or financial resources by government agencies, and the requisite in-kind and financial contributions are just some of the challenges private landowners interested in doing conservation face, she said.
Despite the challenges, landowners are likely to participate in projects where they have a good rapport with the partnering agency and individuals, and where there is appropriate technical expertise, assistance with permitting, complete implementation funds, controlled access, and some long-term maintenance funds, she said.
Government agencies need to provide incentives for landowners to undertake conservation efforts and recognize their need to remain fiscally sound, she concluded.
“Understand that long-term biological success requires short-term political and economic incentives,” she said.
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An Overview: DOFAW T&E Plantings on Kaua`i
“We’re getting a lot of seedling recovery in mesic forests and are really starting to get a lot of [native plants] coming up on their own. In terms of rare plants, not so much,” said Michael Wysong, a botanist and manager of the Kaua`i Natural Area Reserves.
Wysong, who was hired by the DLNR’s Division of Forestry and Wildlife in 2007, provided an overview of his agency’s success with rare plant restoration on Kaua`i.
Results have been mixed, at best.
Between 1987 and 2007, DOFAW built 44 rare plant exclosures on Kaua`i totaling nearly 120 acres. Thirty-three protected areas contained threatened or endangered species, while 11 were created specifically for outplanting. (Outplanting also occurred in six of the 33 protective exclosures.) Most of the exclosures were less than an acre in size.
Between December 1990 and August 2007, DOFAW outplanted 4,119 threatened and endangered plants representing 53 species. Most species had fewer than 50 individuals planted, he said.
After conducting an inventory of 10 of the 17 exclosures where outplanting occurred, Wysong and his staff found that outplantings survived in seven of them. Overall species survival at all sites was a mere 15 percent, he said, adding that of the 53 species planted, only 33 (62 percent) remained.
Because survivorship was better when more individuals were planted, Wysong concluded that DOFAW needs greater nursery production.
He added, “If we put a lot of plants out, to ensure survival of the outplants, we need to better match outplants to their habitat requirements and discontinue outplanting with species or sites that don’t work.”
Better genetic tracking, greater species representation, and prioritized outplanting are also needed. The rarest should come first, he said.
His abstract notes that in the past five years, “focus for rare plant protection on Kaua`i has shifted from an emphasis on individual plant population protection to larger scale habitat and watershed protection.”
Since 2007, larger exclosures totaling more than five thousand acres have been built, mostly by the Nature Conservancy of Hawai`i. Wysong said that once all planned fencing is complete, more than 8,000 acres and an additional 29 species will be protected.
Teresa Dawson and Patricia Tummons
Volume 22, Number 3 — September 2011