2012 — Maui Invasive Species Committee (MISC)

The little fire ant-bad news for food crops

Posted on June 30, 2014 by Lissa Strohecker

Liitle fire ant colony inside a macadamia nut

Little fire ants have many queens in the colony, and by moving a queen the population spreads to new areas. If you live in an area infested with little fire ant, don’t bring the pest to your new home. Photo courtesy of Hawaii Department of Agriculture.

The little fire ant, Wasmannia auropunctata, is a pest with a deservedly nasty reputation. Alone, this wee ant is neither aggressive nor impressive, but with her sisters, living in a network of colonies stretching from tree-top to ground, she has a dramatic impact. Once established, little fire ants are more than a pest, they will put the kibosh on agriculture. Little fire ants have already shut down fruit orchards in the Hilo area and their establishment threatens agriculture throughout the state.

Little fire ants do not compete between colonies; rather, they cooperate, blanketing the ground and trees and outcompeting other ant species for food and resources. Other insects and animals may also be pushed out and end up abandoning highly-infested areas to the little fire ant.

As little fire ants find homes in bananas, citrus, rambutan, and coffee trees, farmers faced with new difficulties in harvesting their crops. Because the ants don’t hold on well to branches, scads of tree-dwelling ants rain down on workers become trapped in their clothing, and sting in self-defense.

fungus on coffee infested with little fire ants

Stinging ants raining down upon harvesters is enough of an obstacle for coffee infested with little fire ant, but additionally, yields are reduced because little fire ants protect aphids that support plant disease, like this fungus. Photo by Cas Vanderwoude

In the Galapagos, little fire ants have made harvesting coffee one of the most difficult ways to earn a living; coffee harvesters now command a higher wage than other agricultural workers to compensate them for the aggravation. Increased costs affect farm profitability; in several areas of the Galapagos, coffee plantations lay abandoned because of the little fire ant. In Kona, the famed coffee-growing area, and elsewhere in the state, most coffee is harvested by hand. The spread of LFA into coffee plantations will be a huge blow to an industry already struggling to address the coffee borer beetle, another invasive pest that threatens the coffee industry as it reduces yields.

Little fire ants threaten more than just coffee. In Brazil and Cameroon, little fire ants infest cacao farms. In Puerto Rico, Florida and New Caledonia, little fire ants have overrun citrus

Cacao and other tree crops are particularly susceptible to little fire ant infestations. Photo used by permission from Cas Vanderwoude.

groves and in some areas practically blanket the ground.

The ants are causing havoc with other types of agriculture as well. Little fire ants cause blindness in animals and livestock, poultry, and pets in infested areas have a much higher incidence of blindness than do animals without LFA.

Controlling these ants is extremely difficult, especially for tree crops, as few pesticides are registered for use in trees and the bait must stick to branches long enough for the ants to find it. Existing control techniques rely on traditional pesticides; an effective organic method has yet to be developed.

As with any invasive species, preventing spread and establishment are the most cost-effective approaches. Eradication is possible only if the population is small. Once established, these ants may be forever. Little fire ants are widespread on the eastern side of Hawaii Island and beyond eradication in that area, but further spread throughout the state can be prevented. Help protect agriculture on Maui, as well as your own quality of life. Support efforts to prevent their movement between islands and quarantine and check any plants or soil you bring on to your property for little fire ants. Learn more at www.lfa-hawaii.org and www.littlefireants.com.

By Lissa Fox Strohecker. Originally published in the Maui News, May 13th, 2012 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.

Invasive plants=Less water

Posted on June 27, 2014 by Lissa Strohecker

This rainforest, in Puu Kukui on West Maui, is an example of an open canopy rainforest typical of native rainforest in Hawaii. This forest acts like a ‘sponge,’ absorbing water from rain and gently releasing to recharge streams and aquifers. MISC file photo

When rain falls from the sky by the bucket-load it can be tempting to take water for granted, but the trip from raincloud to tap relies on effective, functioning natural systems. In Hawai‘i, alien plants disrupt the forest’s ability to capture water.

Water follows a cycle through the environment. Water over the ocean evaporates becoming atmospheric moister, as it travels over land it condenses into clouds, falling to Earth as rain or fog drip. Once on the ground, water has three paths: 1) it’s taken up by plants that use it to move nutrients through their cells, then return it to the atmosphere via transpiration; 2) it fills streams, lakes and rivers, eventually returning to the ocean–minus what was used for irrigation or lost through evaporation; or 3) it seeps through the soil into underground pools called aquifers. These aquifers supply most of the water we use to drink, bathe, and grow our food.

Forests have evolved differently to take advantage of prevailing water cycles in their regions. In South America and Africa the greatest diversity of plants is found up in the canopy. In Hawai‘i most plant species are found in the lower third of the forest, closer to the forest floor. Hawaiian understory plants need sunlight filtering through an open canopy. Koa and ‘ōh‘ia, the dominant Hawaiian canopy trees, grow in such a way that light reaches the shrubs and groundcover below.

Koa and ‘ōh‘ia pull water from passing clouds as fog drip; the curved leaves of koa provide surface area to collect moisture from clouds and channel it down leaf tips to the forest floor. Spongy plants on ‘ōh‘ia branches and trunks absorb moisture from passing clouds. Alien species disrupt the system.

Strawberry guava, Psidium cattleanium, has invaded Hawaiian rainforests, growing so dense and so

Strawberry guava invaded forest in Makawao Forest Reserve

The invasive tree strawberry guava chokes out native plants. As it sheds bark, strawberry guava provides no habitat for the plants growing on the trunks of native species. Photo courtesy of Forest and Kim Starr.

fast that it chokes out other plants. A strawberry-guava-invaded forest captures water differently than our native forests. In Hawai‘i Volcanoes National Park researchers found that a forest dominated by strawberry guava delivered less water to the forest floor than an intact native rainforest. Researchers noticed several differences between the two forest types: more rain ran down the stems of strawberry guava than ‘ōh‘ia but less water was pulled from the passing clouds. This could result from structural differences. ‘Ōh‘ia have aerial roots and furrowed bark carpeted with mosses and small plants called epiphytes. The epiphytes and aerial roots soak up water from passing clouds. Strawberry guava bark is smooth and regularly shed; few plants grow on its trunk and branches.

Other invasive species disrupt the water cycle by sheer size—leaf size. Miconia trees with three-foot long leaves sweep into the forest, stealing light from the understory and transforming it into darkened forest, the soil bare but for miconia seedlings. As another researcher on Hawai‘i Island discovered, the huge leaves are more than just light-hogs. They collect water as if they were huge tarps, and, as anyone who has stood near the edge of a tarp in a rainstorm knows, it’s only a matter of time until the water

The forest floor under a miconia invasion is bare, often with exposed roots. Not a good sign for water collection. MISC file photo

dumps down. The drops running off of miconia turn out to be the largest drops ever measured. Larger drops hit the ground harder, and where miconia has smothered the understory, those drops fall on bare soil. Huge drops compact soil particles, preventing water from seeping down to aquifers, instead causing it to run off, carrying topsoil into streams and eventually the ocean where it can smother coral reefs.

These are only some of the ways invasive plants alter the forest’s ability to capture water. Water-hungry plants like Himalayan ginger pave the forest floor in tough roots. Huge trees like eucalyptus require more water to carry nutrients to their crowns than smaller trees. Unfortunately, the list goes on. Healthy forests mean reliable sources of water. Keeping invasive plants out of native forests is one way to help keep the water flowing from raincloud to tap

By Lissa Fox Strohecker. Originally published in the Maui News, March 11th, 2012 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee

From Paper Maps To GPS Units, The Evolution of Technology in Conservation

Posted on December 19, 2012 by MISC Leave a Comment

GPS-enabled field computers help pilots and crews record where they’ve already surveyed and where they need to go.

If smart phones, tablets, and global positioning systems (GPS) are on your wish list, you are not alone. These gadgets are proving essential in the efforts to protect native Hawaiian ecosystems.

Accurate mapping has always been crucial to surveying for and controlling invasive species. Back in the mid 1990s Maui field crews first began finding miconia. Though not very long ago, the technology available then seems pre-historic today. Using altimeters and orienting from known physical landmarks, they would record plant locations by drawing dots on photocopies of topographic maps. These paper maps were filed away for future use. Subsequent visits meant more hand-drawn maps. Sometimes the only way to find a specific locale was to bring along someone who had been there before.

Early attempts to create electronic maps involved scanning topographic maps into a computer and then drawing dots to estimate locations using computer programs intended for design and drafting. There was an electronic record, but it was time consuming to create and not especially accurate.

Then along came the GPS, promising a precise reading of position and time anywhere on earth, in any type of weather, provided the receiver had an unobstructed view of 4 satellites. Early GPS units were expensive and heavy. Accuracy was, well, not all that accurate. That unobstructed view of satellites was often hard to come by given terrain and canopy cover—especially in Maui’s dense rain forest, where miconia was spreading. To record a position, field crews carried a pole that they had to piece together and snake up through the overhanging tree limbs. With luck and patience, they could get enough satellites to provide a reading and not lose the antennae in a tangle of branches.

Rather then depending on paper maps and memory, field crews now load maps onto GPS units that allow them to record where they control plants and guide them to where they need to search.

GPS receivers have improved dramatically. Now field crews load maps onto GPS units and follow pre-recorded trails to locate remote populations of invasive plants. Rather than relying solely on the memory of a few people, crews can be dispatched to remove plants even if no one among them has visited the area before. Hand-drawn maps are a thing of the past, transforming an unwieldy stack of maps into a few digital files, making it possible to track work on hundreds of thousands of miconia plants.

Helicopters survey vast areas for invasive plants while flight lines are recorded on GPS units to ensure thorough coverage. Spotters in the aircraft record precise locations of plants so crews can revisit the locations either on the ground or by air. Each helicopter has a GPS-enabled field-rugged laptop loaded with maps to help guide the pilots and spotters.

Even flight following has changed dramatically. Pilots and crew used to have to stop what they were doing and radio in every 20 minutes to let managers know they were safe. Often, terrain blocked radio calls and pilots had to spend valuable time flying to an area where they could make contact. Now flight followers back at headquarters can monitor the helicopter’s whereabouts and status using a computer program synchronized with the GPS unit on the aircraft.

Technology has helped to increase efficiency and effectiveness of field crews on Maui and now these tools are in the hands, or pocket, of anyone with a smart phone. While plans are in the pipeline for invasive species reporting apps specific to Hawai‘i, there are many other options for reporting invasive and rare native species. If you are a cell-phone shutterbug you can easily send photos to email addresses-just type in an email where you would normally enter a phone number. You can also report online via the reportapest website at reportapest.org. So next time you see plant or animal that causes you to raise an eyebrow just snap a photo and send it in and stay posted for future tools to help you learn more about the plants and animals in your backyard.

By Lissa Fox Strohecker. Originally published in the Maui News, December 9th, 2012 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.
You can find all the articles in the Kia‘i Moku series http://www.hear.org/misc/mauinews/

Plants Out of Place-Native to Hawaii but Invasive Somewhere Else

Posted on December 6, 2012 by Lissa Strohecker Leave a Comment

The native Hawaiian ecosystem is often described as fragile and prone to invasion, so it may come as a surprise to find that some of our island species on the most unwanted list of invasives in other parts of the world.

Native to Hawaii, naupaka, or Scaevola taccada , invades a beach in Fort Lauderdale, Florida. Naupaka chokes out plants native to Florida and may alter nesting habitat for sea turtles. Photo courtesy of Forest & Kim Starr.

In Hawai‘i, beach naupaka decorates miles of coastline, but in Florida this attractive plant is listed as a state noxious weed. Known as Scaevola taccada to the scientific community, naupaka outcompetes the endangered Scaevola plumieri native to Florida. In the Caymen Islands in the Carribean, where naupaka is also invasive, there is some concern that sea turtles may not be able to access nesting sites with mounds of naupaka blanketing the coasts. Naupaka was introduced to Florida as a landscaping option.

Pōhinahina is another Hawaii coastal native that’s proven invasive elsewhere. Crews on the coast of North Carolina remove this dune-destroying shrub. Photo courtesy of beachvitex.org

In Hawai‘i, pōhinahina, Vitex rotundifolia, sometimes known as beach vitex, grows alongside naupaka but it’s wreaking havoc elsewhere. Pōhinahina is a sprawling coastal shrub with small purple flowers. Landscapers introduced pōhinahina to the Southeastern and Mid-Atlantic States, where it now smothers coastlines, choking out native plants like the endangered sea beach amaranth. Pōhinahina is a noxious weed in North Carolina. Virginia has enacted a statewide quarantine in hopes of stopping its spread. Communities gather regularly to fight back this kudzu of the coastline.

This ‘a‘ali‘i grows on the slopes of Haleakalā, but it has also taken over rangeland in Kenya. Photo courtesy of Forest & Kim Starr.

‘A‘ali‘i, or Dodonaea viscosa, is another hardy Hawaiian native that’s problematic elsewhere. This drought tolerant plant grows in central Maui and up the slopes of Haleakalā. It’s a tough shrub with distinctive winged seedpods, and, as it turns out, doesn’t taste so great–at least to the cattle of Kenya and Uganda, where ‘a‘ali‘i takes over rangeland.
Like many of Hawai‘i‘s native plants, these species are indigenous to Hawai‘i, meaning that they are native to Hawai‘i as well as other places. Naupaka is native throughout the Pacific and India, growing on coastlines from Okinawa to Oman and from Micronesia to Madagascar. Pōhinahina’s native range stretches across the Pacific Rim and into Southern Asia. And ‘a‘ali‘i is a cosmopolitan species found from Florida to the Sonoran deserts into Mexico and across the Pacific to New Zealand and Australia.
These three plants have developed ways to spread their keiki far and wide: plentiful seeds that float and survive a long bath in salt water. ‘A‘ali‘i seeds spread inland by catching the wind and by sticking to the feathers of birds. These strategies help explain why these plants are native to such a huge area, and how they were able to reach Hawai‘i. But when these plants are released from the checks and balances found in their native habitat–competition with other species, predation by insects, even climate and geography–there’s a possibility of a problem.
An invasive plant is not inherently bad; it has developed strategies necessary for its survival. In Hawai‘i these three plants play an important role–protecting beaches from erosion and providing habitat for native animals. However, what constitutes a means to survive in one place can translate into an invasive characteristic elsewhere. It’s just a matter of the right plant in the right place.

By Lissa Fox Strohecker. Originally published in the Maui News, November 11th, 2012 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.
You can find all the articles in the Kia‘i Moku series http://www.hear.org/misc/mauinews/

Ants and Hawaiian Seabirds – A Deadly Combination

Posted on November 9, 2012 by Lissa Strohecker 3 Comments

The Hawaiian archipelago is crawling with ants and not a single one belongs here. Humans

A petrel is covered by big-headed ants on Kure Atoll. While ants can be a nuisance for people, the insects can maim or kill nesting seabirds.
SHELDON PLENTOVICH photo

introduced over forty-five ant species to the islands. While they’re a nuisance to people, to Hawaiian seabirds they are a major problem.

Sheldon Plentovich is the Coastal Program Coordinator with the Pacific Islands Fish and Wildlife Office. She has studied some of these impacts. “Seabirds nesting in Hawaii do not have effective defenses against dense supercolonies of invasive ant species,” she says. And even though high densities of invasive are present, the seabirds return to the same areas to nest as they have for generations.

In March, throughout Hawai‘i, Wedge-tailed Shearwaters dig burrows for nesting along the coastline. Unfortunately tropical fire ants, Solenopsis geminata, often inhabit these areas. Plentovich isn’t sure whether the ants are trying to eat the birds or if the ants are just defending their nest. Adult birds can fly away to escape the ants but the chicks can’t. “They’re programmed to stay in the nest,” explains Plentovich. In their fury, the six-legged invaders destroy the tender webbing on the chicks’ feet. These ant attacks affect the development of the chicks as well. Oftentimes chicks that have been attacked fail to grow feathers.

Plentovich knocked back the population of tropical fire ant on one islet off the coast of O‘ahu and, as expected, found that the seabirds had greater fledgling success compared to those on an islet still infested by tropical fire ant.

Tropical fire ants attack a wedge tailed shearwater chick on islet off Oahu. These attacks can permanently disfigure birds’ feet and even lead to chick’s death. Photo Sheldon Plentovich

Tropical fire ants belong to a group designated as “tramps.” Tramp ants are omnivorous, and because they do not compete between colonies, form dense supercolonies made up of multiple queens. These dense supercolonies can outcompete everything else for food and resources. And since it takes a queen to start a new colony, the greater density of queens makes it easier for these ants to be spread around by people. Not surprisingly tramp ants include some of the Pacific’s most devastating invasive species, such as the little fire ant. They’ve hitched rides to the furthest reaches of the Hawaiian archipelago.

Johnston Atoll is one of the most isolated atolls in the world, 860 miles west of Hawai‘i. The Atoll is strictly a wildlife refuge where red-tailed tropicbirds nest alongside shearwaters, petrels, terns, noddies, and boobies. Unfortunately the atoll has become a haven for the yellow crazy ant or Anoplolepis gracilipes. This tramp ant doesn’t bite or sting the birds, rather it sprays them with formic acid and birds don’t respond well to formic acid. Animals that can seek out fish from the sky are left with swollen puffy eyes. Plentovich has seen Red-tailed Tropicbirds that have “toughed it out” staying to nest despite being swarmed by ants, spraying formic acid.

Footage of a Red-tailed Tropicbird swarmed by yellow crazy ant on Johnston Atoll. These invasive ants swarm nesting seabirds. Seabirds show high nest fidelity and return to the same location to rear their young despite the presence of these ants. Video by Sheldon Plentovich

Ants impacts can vary from place to place. The big-headed ant, Pheidole megacephala, is one of the most common ants in Hawai‘i. On Moku‘auia off Oahu, eradicating big-headed ant had no effect on the hatching and fledging success of shearwater chicks.

Big-headed ant attacks Bonin Petrel chick on Kure Atoll. Big-headed ants are one of the most common ants in Hawaii but on Kure the population reached such a high density the ants were attacking everything in sight. Photo by Cynthia Vanderlip

But on Kure Atoll the big-headed ant has been seen swarming birds and eating chicks alive. Plentovich thinks ant density is the reason. On Kure, the population of big-headed ants was 5 times more dense than it ever was on Moku‘auia. “They’re eating everything they encounter,” says Plentovich.

Chances are people inadvertently brought ants to isolated Johnston and Kure Atolls. All it takes is a single queen ant in a piece of cargo to start an infestation. And eradicating an established infestation is extremely difficult work. Plentovich is hopeful that new techniques will lead to the eradication of yellow crazy ant on Johnston atoll where other techniques have been unsuccessful. She’s seen how controlling an invasive ant can influence the whole ecosystem. When she reduced the population of invasive ants on offshore islets she saw an increase in the diversity of insects and “native plants survived better-the ‘ilima started taking off.”

By Lissa Fox Strohecker. Originally published in the Maui News, October 14th, 2012 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.
You can find all the articles in the Kia‘i Moku series http://www.hear.org/misc/mauinews/

A hidden world in Maui’s streams

Posted on October 12, 2012 by Lissa Strohecker 1 Comment

After 27 years of working with the Department of Land and Natural Resources, aquatic biologist Skippy Hau has become pretty familiar with Maui’s streams and the creatures dwelling in them. But there are always surprises. Several years ago, Hau discovered hīhīwai, one of two species of native Hawaiian freshwater snails, crawling single file up the cement bottom of a channeled stream next to a West Maui grocery store. The stream is typically dry, with few rocks to shelter the hīhīwai, but there they were.

This hīhīwai, a native Hawaiian snail, clings to a rock in a Maui stream. The presence of slow-movnig hīhīwai can indicate the frequency and quantity of water needed for a healthy stream.

It’s amazing that Hawaii has any native freshwater species to begin with. Streams in Hawai‘i are 2,400 salty miles away from the nearest continental sources of freshwater. Yet fish, crustaceans and mollusks colonized island waterways well before the first Polynesians arrived, most evolving into species found no where else in the world. These animals have evolved to cope with intermittent stream flow and climb waterfalls. ‘Ōpae kala‘ole, an endemic crustacean, is the best climber of all, known to scale 100-foot cascades. But like other native Hawaiian plants and animals, these riparian creatures now face threats from introduced species.

Invasive armored catfish have added the eggs of the native ‘o‘opu (goby) to their diet. Guppies and mosquito fish devour Hawaiian stream dwellers’ larvae and contribute to the decline of native damselflies at low elevations. Swordtails and other non-native aquatics spread new diseases to native fish. Tilapia compete with native water birds for food and released pet turtles dine on ‘o‘opu.

‘O‘opu nōpili. Photo by Skippy Hau

‘O‘opu nākea in ‘Iao stream. Photo by Skippy Hau

‘O‘opu ‘alamo‘o. Photo by Skippy Hau

Most of these invasive species were intentionally introduced – starting with Asian immigrants bringing in Chinese catfish, rice-paddy eels and other species for food in the 1800s. Mosquito fish, or topminnows, were released into streams from the 1900s through 1960s to control mosquitoes. This was an era when state officials frequently introduced game species, such as trout, bass and tucunare, or peacock bass, into streams. During the 1970s, managing resources for native species became more important; game fish are no longer introduced.

In the 1980s and ’90s, aquarium fish and mollusks began appearing in Hawaiian streams. In addition to guppies and swordtails, a variety of cichlids and ramshorn snails now snack on larvae of native stream animals returning to the ocean. Aquarium owners who dump unwanted pets are the most likely source of this problem, which is ongoing.

Hīhīwai, like all Hawaiian stream dwellers, are only part-time residents. They spend the first year of life in the ocean, then ascend single file into a freshwater stream. Not all make it as they colonize the stream’s upper reaches, instead becoming a source of food for other riparian species. In addition to the hīhīwai, another native mollusk, five species of fish and two crustaceans spend a part of their lives in the ocean. During rare flood events, these freshwater animals move quickly upstream for the less salty part of their lives, finding shelter in upper elevation pools.

Hau regularly monitors the slender tributary of ‘Iao where he first witnessed the climbing snails. When it exceeds a trickle, he dons a snorkel mask and peers under rocks for slow-moving hīhīwai. By carefully studying Maui’s streams, Hau has documented the frequency and volume of water necessary for our native freshwater animals need to move between ocean and stream.

These remarkable aquatic animals need our help. Don’t release unwanted pets into streams. If your fish is too large for your aquarium, contact a local pet store. They often take back fish and snails. Consider selling or gifting your unwanted fish or turtle online or to a friend.

Learn more about the fascinating animals in Hawaii’s streams and how to help protect them at hawaii.gov/dlnr/dar/streams.html.

By Lissa Fox Strohecker. Originally published in the Maui News, June 10th, 2012 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.
You can find all the articles in the Kia‘i Moku series http://www.hear.org/misc/mauinews/

The ‘Ua‘u and the threat of invasive species

Posted on September 13, 2012 by Lissa Strohecker Leave a Comment

Hawai‘i is famous for rare birds: scarlet honeycreepers that dart through the rainforest and gold-flecked owls that hunt at twilight. But another Hawaiian bird lives most of its life at sea. The ‘ua‘u , or Hawaiian petrel, returns to land under the cover of darkness—and then only to nest. Now is the time to be on the look out for this cryptic bird; the chicks are fledging.

An ‘ua‘u chick hides in his burrow awaiting his parents return. In the meantime the chick is vulnerable to passing rats, cats, and mongoose who can quickly scoop the chick from his hiding place.Photo by Jay Penniman

Named for their eerie nighttime call, “uuua-uuuu,” the ‘ua‘u alight on land for only a few minutes before ducking into their underground burrow. Their nesting locations are remote, difficult to access. Counts at sea estimate the population at around 20,000, low enough to earn a place on the Federal Endangered Species list.

Fossils indicate that ‘ua‘u were once so plentiful in Hawai‘i they blackened the sky. Prior to humans’ arrival in these Islands, ‘ua‘u and their feathered friends ruled these Islands. ‘Ua‘u built burrows from the coastline to the mountaintop, digging into soil and taking advantage of existing crevices. But populations have dwindled to a fraction of what they were, due to habitat loss and predation. Now invasive species threaten to overrun the sliver of habitat remaining for native birds, while predators lurk outside their burrows.

Having evolved without mammalian predators, ‘ua‘u are particularly naïve, both in their choice of nesting location and how they rear their young. Ground nesting, even in a burrow, leaves petrel chicks and eggs vulnerable to attacks by stealthy rodents or felines. Pigs, goats, cattle, deer, and people trample burrows, crushing the egg or the chick inside.

‘Ua‘u only lay one egg per season, and both parents invest much energy and effort in rearing the chick. A trip to the grocery store for an ‘ua‘u parent is a two-week, 6000 mile journey along the northwest Hawai‘i an islands to the Aleutians and circling back down to Hawai‘i , among the longest feeding routes of any known seabird. Unfortunately, there is no babysitter; the chick’s safety depends on remaining underground, hidden from predators.

While the species as a whole demonstrates remarkable flexibility in choosing nesting sites—from dense thickets of uluhe fern to frigid cliff faces on the summit of Haleakalā –individual birds are guided by habit. They return to the same burrow year after year, despite the likelihood of a cat laying in wait.

Many people are working to protect the ‘ua‘u . Biologists arelearning more about these remarkable birds by observing their burrows and tracking their movements. A major colony was re-discovered on Lāna‘i in 2006, but the birds’ native habitat was being choked out by invasive trees. To protect this colony, staff from the Lāna‘i Native Species Recovery Program and volunteers are fighting back acres of strawberry guava and replanting the uluhe fern that form a protective blanket over the burrows. Within Haleakalā National Park, park staff controls predators that attack ‘ua‘u .

‘Ua‘u, like this one, are often disoriented by streetlights and end up on the ground. If you find an ‘ua‘u safely pick it up and call the Maui Nui Seabird Recovery Project, (808) 280-4114. Photo by Jay Penniman

You can help as well. When petrel chicks leave the burrow for their first time they can become disoriented by the bright lights of civilization. Some birds come crashing down onto buildings or roads. A grounded chick is defenseless against predators and threatened by cars. If you see a petrel on the ground, carefully pick it up with a cloth or towel and place it in a well ventilated box. Do not try to feed the bird. Call Maui Nui Seabird Recovery Project (808) 280-4114.

By Lissa Fox Strohecker. Originally published in the Maui News, September 9th, 2012 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.
You can find all the articles in the Kia‘i Moku series http://www.hear.org/misc/mauinews/

The nose knows: dogs sniff out invasive species

Posted on August 16, 2012 by Lissa Strohecker Leave a Comment

A beagle with the U.S. Customs and Border Protection inspects passengers luggage in an airport. The Hawaii Department of Agriculture has done similar work with dogs in the past; a recent bill passed by the Hawaii State Legislature will help bring the program back. Photo by James Tourtellotte.

This fall there will be some new faces at the Hawai‘i Department of Agriculture (HDOA)– furry faces. The Hawai‘i Detector Dog Program is returning, thanks to restored funding from the state legislature and matching federal funds. Alongside their human handlers, these four-legged inspectors will screen incoming cargo and luggage on O‘ahu to help prevent plant and animal pests from becoming established in Hawai‘i.

Hawai‘i’s detector dogs will be sniffing for brown tree snakes that may have stowed away in shipments from Guam, but they will also inspect other cargo arriving at both the Honolulu airport and O‘ahu military bases, including mail and parcel shipments.

The 20 year-old program was cut in 2009 due to a lack of funds. Prior to the program’s demise, busy beagles and handlers bagged seven snakes in a 14-15 year period. During inspection blitzes at the Maui airport, dogs uncovered more than a thousand instances of undeclared produce and vegetation, including a shipment of persimmons infested with mealybugs not known to be in Hawai‘i. Hawai‘i’s airport dogs also serve as ambassadors for HDOA, letting passengers know with a friendly wag that their luggage was inspected behind the scenes as well as in the baggage claim area.

The new inspectors will be in good company. Man’s best friend, long called upon for helping humans in search and rescue, hunting, and police work, now is lending a nose on a variety of conservation fronts.

Kristine Lesperance and Dexter hunt the invasive rosy wolf snail in the Waianae Mountains of Oahu. Photo by Oahu Army Natural Resource Program.

Kristine Lesperance of O‘ahu Detection Dog Services and her lab-mix named Dexter have been working hard to save native Hawai‘i an tree snails, or Achatinella,in the Wai‘anae Mountains. Dexter sniffs out invasive animals that prey on native tree snails: the cannibalistic rosy wolf snail and Jackson’s chameleon. Dexter can distinguish between a rosy wolf snail, a giant African snail, and native snails by scent. When he finds one, he sits down and waits for his reward. He can track chameleons by the smell of their scat, a definite advantage for finding these cryptic creatures.

Lesperance says dogs are great for determining the presence or absence of an animal across large areas. Depending on the species the dog is searching for and how odoriferous it is, it may take awhile. With the rosy wolf snail, Dexter doesn’t cue into the scent until he’s one-half inch to two inches from the snail, taking up to 30 minutes to find one; he does better with Jackson’s chameleon scat, finding it from several feet away, but, when working as a search and rescue dog, Dexter can smell a person a quarter mile away.

In Missoula, Montana, trainer Dalit Guscio is about to reward Seamus. He’s been tracking down invasive Dyers woad plants. Seamus and Dalit are with the Montana-based Working Dogs for Conservation. Photo by Elizabeth Stone.

In Montana, dogs are sniffing out invasive plants in the field, outperforming their human counterparts at finding scattered small plants. Elsewhere, dogs are finding bees, pythons, rare plants, cane toads, tortoises, termites, and even root fungus. “I think we could use dogs to find pretty much anything that has a scent,” Lesperance says, adding that further work will help determine how dogs can be most effective in different conservation scenarios.

Although dogs have been trained to help in conservation for 10-15 years, “we’re really just seeing the beginning” says Lesperance. Our new four-legged recruits will help close gaps in agricultural inspection, but many opportunities exist for canine eco-detection services. Who knows whose nose will be hard at work protecting Hawai‘i?

By Lissa Fox Strohecker. Originally published in the Maui News, August 12h, 2012 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.
You can find all the articles in the Kia‘i Moku series http://www.hear.org/misc/mauinews/

A changing climate and the plight of the ‘i‘iwi

Posted on August 6, 2012 by Lissa Strohecker Leave a Comment

An adult ‘i’iwi sips nectar form the flowers of a native lobelia in the Waikamoi preserve. The habitat for the i”iiwi and other Hawaiian honeycreepers is threatened by climate change. As climate warms mosquitoes that transmit disease to the native birds will increase in range. Photo by Forest and Kim Starr

On just about any given day you can find ‘i‘iwi, among the more charismatic species of Hawaiian honeycreepers, flitting around Hosmer’s grove, just past the entrance to Haleakalā National Park. These energetic little bursts of red flit from tree to tree feeding on the nectar of ‘ōh‘ia flowers and the occasional spider or insect. Once abundant on all islands from sea level up into the mountains, these brilliant birds are now rarely seen lower than 5000 feet. Below that elevation, avian malaria, a bird disease transmitted by mosquitoes, has decimated Hawaiian honeycreepers. Today, even the birds subsisting in the high-mountain pockets of habitat are threatened—not only by invasive plants and animals, but also by climate change.

Avian malaria is not new in Hawai’i. Migratory birds carrying malaria regularly visited Hawaiian shores—but before mosquitoes were introduced, the disease had no way to infect resident bird populations. In 1826, sailors on the whaling ship Wellington dumped barrels of mosquito-infested water into a Lahaina canal. That marked the beginning of the end for low- and mid-elevation native honeycreepers.

Since then, mosquito-born diseases have caused two major waves of extinction in Hawaiian honeycreepers. Native forest birds have shown scant resistance to foreign diseases. Those that survive inhabit forests above the “mosquito line,” where neither mosquitoes nor the diseases they carry can thrive. In cooler temperatures, avian malaria can’t reproduce fast enough to infect birds. Thus the largest populations of ‘i‘iwi dwell in the cloud forests of East Maui and Hawai’i; the birds are increasingly rare or nonexistent on islands without tall mountains. ‘I‘iwi have vanished from Lāna‘i and only a few remain on Moloka‘i and West Maui. With a warming climate, the remnants of disease-free habitat may shrink or disappear.

Introduced mosquitoes transmit avian malaria and pox from non-native birds to native birds.

Introduced mosquitoes, such as the tiger mosquito above, transmit avian malaria and pox from non-native birds to native birds. Having evolved in isolation, native birds lack resistance to these diseases. Photo by James Gathany, CDC

And Hawai‘i is heating up. Each decade since 1975, minimum nighttime temperature has increased an average of almost 1°F. Nighttime temperature is the determining factor in estimated elevational range of avian malaria. Over the last 50 years, the mosquito line has steadily marched up the mountain, from 2000 feet in the late 1960s to nearly 5000 feet today.

Climate change may affect our native birds in other ways. Summer storms are predicted to become more frequent, creating more habitat for mosquitoes during their optimum breeding season, increasing their density and the likelihood of transmission of avian malaria. Meanwhile, overall rainfall may decrease, compromising the health of the native Hawaiian rainforest and the inhabitants that rely on it.

The ‘i‘iwi is not the only bird likely to be chased out of remaining habitat by avian malaria and climate change. In Hawaii all of our non-migratory birds, such as the Maui crested honeycreeper or ‘ākohekohe, Maui parrotbill or kiwikiu, and the ‘apapane, face the same danger. These species are unique among the world’s creatures; they exist nowhere else on earth. Many of them are highly significant to the native Hawaiian culture and all play critical roles in their natural environments. Their loss would be devastating.

In response to concerns raised about the ‘i‘iwi’s perilous situation, the United States Fish and Wildlife Service is proposing to list the ‘i‘iwi as federally threatened or endangered, with climate change noted as a factor in its decline. How can you help? Support efforts to address the causes of climate change. Work to protect the remaining natural areas that shelter ‘i‘iwi. And take a trip to Hosmer’s Grove to witness just how spectacular these winged treasures are.

By Lissa Fox Strohecker. Originally published in the Maui News, July 8th, 2012 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.
You can find all the articles in the Kia‘i Moku series http://www.hear.org/misc/mauinews/

Moving on from the Mongoose: the Success of Biological Control in Hawai‘i

Posted on April 18, 2012 by Lissa Strohecker 2 Comments

Achieving balance–in your workplace, at home, on your surfboard, or with your checkbook—makes life manageable. Natural environments depend upon balance as well.

Invasive pests have been disturbing the natural balance of Hawaiian ecosystems for centuries, ever since the arrival of the rat with early Polynesian explorers. Bringing invasive species into better balance with the environment is nothing new here in Hawai‘i. An effective biological control, or natural predator, can transform a devastating invasive species into a mild pest.

The invasive Erythrina gall wasp that threatened the native wiliwili trees, such ans this one, was brought into balance by a parasatoid wasp.

The vast majority of biological control efforts in Hawaii have been successful: pānini cactus that once choked pasture land is now checked by three predatory insects and a plant fungus; white loosestrife or pāmakani is continually attacked by two insects and another plant fungus; and recently, the Erythrina gall wasp, that wiped out ornamental coral trees and threatened the native wiliwili with extinction, was leveled by a parasitoid wasp.

Yet, just as impulsive actions sabotage balance in our own lives—think diet fads and over-exercising–the same kind of recklessness results in greater instability in our environment.

Such is the case with the small Indian mongoose, Herpestus javanicus. In 1872, a sugar planter released nine mongoose on Jamaica with the hope it would control rats in cane fields. The planter considered it successful and published a paper about it. Mongoose populations grew and offspring were sold to plantations throughout the Caribbean, Cuba, and Puerto Rico. In 1883, Hawai‘i plantation owners jumped on the mongoose bandwagon. With little regard for potential impacts, the now defunct Hilo Planters Association released seventy-two mongoose from Jamaica in Hilo. Another batch of mongoose from eastern India was brought to the Hāmākua coast in 1885. Subsequent offspring were released on Maui, O‘ahu, and Kaua‘i. For an unknown reason the crate delivered on Kaua‘i was kicked off the dock. To date mongoose have not established on Kaua‘i, though a single female was found killed by a car in 1972.

The mongoose is an opportunistic predator, introduced to Hawaii in 1883 with little regard to potential impacts on species other than the rat. Today, a potential biological control goes through years of testing to ensure it will have no unanticipated impacts.

Mongoose do eat rats, in Hawai‘i and elsewhere, but mongoose are opportunistic predators eating primarily insects, with birds, eggs, and a handful of plants mixed in. Additionally, mongooses are active during the day, rats at night. The introduction of the mongoose further tipped the balance of the environment in the wrong direction: now both mongoose and rats threaten populations of native birds, particularly ground-nesting species like nēnē and petrels.

The mongoose introduction was not an example of classical biological control; it was an impulsive, untested whim. Today, when researchers look for biological controls for a particular pest, they survey the pest’s native habitat for species that counteract the pest’s invasive characteristics. Before any new organisms are introduced in Hawai‘i, they are subjected to intensive testing in quarantine to determine potential impacts on any other species.

Successful candidates for biological control have evolved over millennia alongside their target; some are dependent solely on the target species for survival. For example, the Eurytoma wasp that saved the wiliwili will die without access to Erythina gall wasps. Consequently, Eurytoma populations will stop short of entirely eliminating the Erythrina gall wasp. Rather it will restore balance, keeping the pest wasp in check.

When mongoose were brought to Hawai‘i, there were no restrictions on plant and animal imports. Impacts on other species were an afterthought, if considered at all. It wasn’t until King David Kalākaua enacted the “Laws of the Hawaiian Islands” that any regulation existed to limit the introduction of new species to Hawai‘i.

Government-led pest management didn’t begin until ten years after sugar growers introduced the mongoose. The provisional government appointed Albert Koebele as the chief entomologist, the first of many tasked with preventing new and controlling existing pest populations

Biological control has a long and successful history in Hawai‘i. In fact, California and Hawai‘i lead the world in successful releases of natural predators. Ever since testing of biological controls began, there have been no incidences of “host-jumping” or biological controls attacking other species. Yes, the infamous mongoose ran amok, but it arrived during an “anything goes” era in Hawaiian history. The mongoose–or any opportunistic predator–would never be considered suitable for introduction by today’s standards. Biological controls are an important tool—sometimes the only tool—that can restore balance in Hawaiian ecosystems.

Originally published in the Maui News, April 8th, 2012 as part of the Kia‘i Moku Column.
You can find all the articles in the Kia‘i Moku series http://www.hear.org/misc/mauinews/