Invasive Animals — Page 3 — Maui Invasive Species Committee (MISC)

Premiere of the new documentary Invasion: Little Fire Ants in Hawaii

Posted on January 6, 2014 by Lissa Strohecker Leave a Comment

In 2009, Waihee farmer Christina Chang was stung on the eye by a tiny ant at her home on Maui. She suspected, and the Hawaii Department of Agriculture confirmed, that this ant was the little fire ant, Wasmannia auropunctata, never before found on Maui. The detection spurred creation of a new documentary, Invasion: Little Fire Ants in Hawaii.

Invasive species introductions to Hawaii often end in regret and a list of should-haves. This film, produced by the Maui Invasive Species Committee, aims to change the result of the arrival of little fire ants in Hawaii. Featuring videography from award-winning film makers Masako Cordray and Chris Reickert, this half-hour film examines the biology, impacts, and potential solutions to the spread of little fire ants through interviews with scientists, farmers, and community on the Big Island reeling from the impacts of this miniscule, but devastating, ant. Viewers will learn how to identify and report new infestations, helping to protect Hawaii from this small stinging ant

The Waihee site is on target for eradication. However, little fire ants have recently been detected moving between islands, raising concern about the establishment of new infestations. On Hawaii Island, the little fire ant is now widespread in the Hilo area where efforts are focused on educating landowners about control options. Infestations are now occurring on the Kona side as well. Research on effective control continues by the Hawaii Ant Lab, a joint project of the Hawaii Department of Agriculture (HDOA) and University of Hawaii. The little fire ant on Kauai is contained within a 12-acre area under active control by HDOA

The film will premiere on Maui January 8^that the McCoy Theater at the Maui Arts and Cultural Center. Doors open at 5pm. An awards ceremony and panel discussion will follow the screening. Food and beverages are available for purchase on site beginning at 4:30pm.

Screenings on other islands will follow. Please RSVP to miscpr@hawaii.edu to reserve a seat. Below is the current screening schedule:

Maui: January 8, McCoy Theater and the Maui Arts and Cultural Center, 5pm
Oahu: January 13, Cafe Julia at the YWCA, 1040 Richard St, 4:30pm
Kauai: January 18, Kauai Community College Performing Arts Center
Hilo: TBA (February 18)
Kona: February 19, Aloha Performing Arts Center, 5pm

The film will also air throughout the state on KITV

Sat 1/11 630-7PM

Sunday 1/12 9-9:30AM

Sat 1/19 4-4:30PM

Sunday 1/20 10:30-11P

Funding and support for the film was provided by the Hawaii Department of Agriculture, County of Maui-Office of Economic Development, US Fish and Wildlife Service, Hawaii Community Foundation-Pikake Fund, Maui Electric Company, Alexander and Baldwin Foundation, Tri-Isle RC&D. MISC and the Hawaii Ant Lab are collaborative projects of the Pacific Cooperative Studies Unit.

Tiny beetle bores down on Hawaii coffee industry

Posted on November 15, 2013 by MISC Leave a Comment

The tiny coffee berry borer beetle is seen here entering the coffee fruit. Coffee berry borer eats the coffee bean, reducing yield dramatically. In four months’ time one beetle will produce 40,960,000 beetles. This pest is only known to be on Hawaii Island and coffee farmers throughout the state are on the lookout. Never bring green coffee or plants between islands. Photo by Andrea Kawabata, UH CTAHR.

Hawai‘i is the only state in the United States where coffee is grown commercially, and Hawaiian coffee, often synonymous with Kona, is beloved throughout the world. Coffee farms have started springing up on Maui in recent years. “There are maybe 20 times more coffee farmers than 10 years ago,” says Sydney Smith, owner of Māliko Estate Coffee and president of the Maui Coffee Association.

But a tiny bark beetle from Africa, Hypothenemus hampei, or coffee berry borer threatens the coffee industry throughout the state. The miniscule pest was first detected in Kona in 2010. It spread like wildfire reaching north Kona, Ka‘ū, Hāwī, and Hilo. The beetle lays eggs inside of coffee berries. Its larvae hatch and begin to feed, hollowing out the bean and leaving little to harvest and roast.

“Once infestation levels exceed 50% of the cherries in the field, the coffee is not worth picking,” says Rob Curtiss, entomologist with the Hawai‘i Department of Agriculture (HDOA). He explained that there are farms on Hawai‘i Island with 80-90% infestation. “After [the beetles] are in the coffee [fruit] there is nothing you can do to kill them.”

People are responsible for spreading coffee berry borers, says Curtiss. Moving infested beans and bags moves the insects. A few infested beans in the back of a pickup truck could mean the introduction of the pest to a new farm—where the beetle population then explodes. Each female can lay 120 eggs, of which there are 10 females for every male. When the females mature, they find a new coffee fruit, tunnel inside, and lay eggs immediately. Their life cycle is approximately 27 days, most of which occurs inside the coffee berry. “Every 30 or so days you can multiply the infestation by about 80,” says Curtiss. “In four months’ time one beetle becomes 40,960,000 beetles.”

Coffee farmers in Kona have been working closely with entomologists and researchers at the Hawai‘i Department of Agriculture and the University of Hawai‘i-College of Tropical Agriculture and Human Resources (UH-CTAHR) to find effective ways to manage the infestation.

By combining several methods of control, some farmers on Hawai‘i Island have successfully reduced infestation levels to below 5%. This system of integrated pest management includes protocols for field sanitation, pruning, monitoring, pesticide application, harvest, and shipping. Instructions can be found in an online publication on the UH-CTAHR website titled “Recommendations for Coffee Berry Borer Integrated Pest Management in Hawai‘i 2013”

The long-term solution may lie in the discovery of an effective predator for the beetle. According to Curtiss, coffee berry borer is an ongoing target for biocontrol research for the Hawai‘i Department of Agriculture. The department’s exploratory entomologist may someday make a promising discovery in Africa, the beetle’s native range.

Currently, an interisland quarantine restricts the movement of coffee plants and unroasted or untreated “green” coffee from Hawai‘i Island to prevent the pest’s spread to other islands.

The coffee industry on Maui and throughout the rest of the state is growing, as this farm in Kaanapalli shows. But coffee berry borer threatens the entire state. Photo by Forest and Kim Starr.

Back on Maui, Sydney Smith has changed the way she runs her farm. “I used to give tours to visitors, but I don’t do that anymore…I’ve removed coffee plants from near our vacation rental.” Smith’s actions stem from concerns that a visitor may have toured an infested coffee farm on Hawai‘i Island and unknowingly be transporting a beetle. “They’re little tiny things that can get in shoes and clothes.”

Coffee berry borer has thus far only been detected on Hawai‘i Island, but Maui coffee farmers have been trained on what to look for. “It’s not if—it’s when,” says Smith.

To learn more about coffee berry borer, visit the UH-CTAHR webpage: www.ctahr.hawaii.edu/site/cbb.aspx and the HDOA webpage: hdoa.hawaii.gov/pi/ppc/cbbinfo/

By Lissa Fox Strohecker. Originally published in the Maui News, November 10th, 2013 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.

The public health threat of invasive species-mosquitoes and dengue

Posted on August 23, 2013 by Lissa Strohecker Leave a Comment

Aedes aegypti is famous the world over for spreading dengue. This species is not established statewide, but it has shown up at the Honolulu International Airport five times since January of 2012. Photo by Muhammad Mahdi Karim

Back in 2001, several East Maui residents started reporting fever, body aches, and rashes. One of the people sickened had just traveled in French Polynesia during a dengue fever outbreak. The Department of Health eventually confirmed 20 cases of dengue fever in East Maui and a crew hired with funds allocated for environmental emergencies went to work removing mosquito habitat. What made this outbreak interesting was that it was spread by the tiger mosquito, Aedes albopictus, common in Hawai‘i.

“We may be the only place in the world to confirm [that] dengue could be spread by the albopictus mosquito. It’s not an efficient carrier of the disease,” explains Gary Gill, Deputy Director of the Environmental Health Administration with the Hawai‘i Department of Health. “In places where dengue is endemic [regularly occurring], it is the aegypti mosquito that is the carrier.”

The invasive mosquito, Aedes aegypti, is famous for spreading dengue. Neither the mosquito nor dengue is widespread in Hawai‘i. Both periodically appear, but luckily not at the same time. Though conditions are prime as Hawai‘i is a global hub for tourism and commerce..

Dengue outbreaks in Hawai‘i are rare and typically occur when someone travels to an infested area, returns to Hawai‘i and is bitten by a mosquito, as happened in 2001. According to Gill, immediate family members and neighbors are at risk, but the common tiger mosquitoes rarely eat from more than one source. The female mosquito finds a person (or animal), and, given the chance, feeds until her belly is about to burst.

In contrast, Aedes aegypti flit from person to person, taking a blood meal from multiple people and spreading any disease carried by the bloodsuckers. Aedes aegypti is not normally found on O‘ahu. “We have not, up until last year, identified any aegypti since the 1940s,” says Gill.

In January of 2012, a Department of Health entomologist collected a trap containing what was later identified as Aedes aegypti at the Honolulu International Airport. “We’ve found aegypti five times in the last year. Every indication is that this mosquito is either living and breeding at the airport, or it is regularly being reintroduced,” Gill says. Mosquitoes can survive in the cabin, cargo hold, or underbelly of an airplane coming from an infested area. Aedes aegypti are originally from Africa but have spread to tropical and sub-tropical regions of the world including Mexico, Asia, and Australia.

Dengue fever is a widespread subtropical disease that is continuously present in areas with established population of Aedes aegypti. This map shows the distribution of Aedes aegypti (blue) and Aedes aegypti and dengue fever (red). Image from Centers for Disease Control

From a public health standpoint having a thriving population of dengue-spreading mosquitoes at the airport is a worst case scenario according to Gill. “A person carrying the virus walks through the airport, and then it spreads to any number of people at the airport who will then take it to wherever they are going. A single population of aegypti could easily spread dengue throughout the state. A dengue-carrier mosquito would be a concern for people who come here as much as for people who live here.” If Aedes aegypti became established throughout Hawai‘i, it would set the stage for a consistent presence of dengue, like does in parts of Central and South America, India, Southeast Asia, and Africa.

Ongoing surveys for mosquitoes are the best way to ensure early detection of this species. The Department of Health continues to monitor mosquitoes at Honolulu International Airport, but surveys are limited to that airport and don’t include surrounding areas. Funding cuts in 2009 gutted the Department of Health. At one point 40 people worked on O‘ahu on environmental health but now only seven positions remain. Staff cuts throughout the state have left no capacity for mosquito monitoring elsewhere. “What’s at Kahului? We have no idea,” worries Gill.

The Department of Health is working with Hawai‘i’s Departments of Agriculture Transportation to explore options for mosquito surveys at airports and harbors statewide. They are working to reduce mosquito habitat at the airport, removing bromeliads and dark undergrowth and replacing it with less mosquito-friendly landscaping. Gill encourages homeowners to do the same, along with removing or changing water in outside open containers every week. For now it’s our best hope. Unless and until capacity is restored at the Department of Health, early detection of this devastating mosquito is up to the public.

By Lissa Fox Strohecker. Originally published in the Maui News, August 11, 2013 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.

Hawaiian land snails– a tale of evolution worthy of protection

Posted on July 22, 2013 by Lissa Strohecker Leave a Comment

The tale of Hawaiian land snails began millions of years ago as the first plants and animals began to colonize the islands. Researchers don’t know exactly how snails arrived – perhaps stuck to the feathers of a bird or on a floating tree trunk. But in a remarkable story of evolutionary radiation, some 21 or more of those first species that arrived over the millennia gave rise to more than 750 distinct species. Of those, 99% are endemic to Hawai‘i – found here and nowhere else.

This species of Newcomb’s tree snail used to be widespread on Maui but today is only known from a handful of places in the West Maui Mountains thanks to habitat loss and invasive predators-rats and the rosy wolf snail. Baby snails, like this one riding on mom, are rare. Photo courtesy of Hank Oppenheimer

Famously varied in color and shape, Hawaiians called them pūpū kuahiwi, or high-hill snails. Early Europeans collected these jewels of the forest, selling them as lei or to collectors. These snails are still highly valued. Current efforts focus on saving remaining species; high-elevation snail refuges are built to protect them.

Often native snails are found only on one island, or in a single valley or ridge, teetering on extinction because of habitat destruction, shell collection, and invasive species. Adding to the challenges, many Hawaiian land snails reproduce at what is truly a snail’s pace: some species are 3-7 years old at first reproduction and have only 4-7 young per year. They grow slowly—only 0.2 to 0.4 cm a year. Compare this to the invasive giant African snail (Achatina fulica) which reproduce at one year of age, lays up to 600 eggs annually, and grows about 2.5 cm per year.

One species of snail endemic to Maui, Newcomb’s tree snail or Newcombia cumingi, was once found from Lahaina to Makawao, but like most land snails, has become increasingly rare during the latter half of the 20^th century. It was last seen in 1938 by Bishop Museum researchers then rediscovered in 1994 by resource managers with the Maui Land and Pineapple Company’s Pu‘u Kukui Watershed Preserve (PKW).

“One hundred years ago they [native snails] were everywhere,” explains Dr. Kenneth Hayes, a University of Hawai‘i researcher who, along many others, has been working to find out how many West Maui snails remain. Today, 50 percent or more are gone, many turned into escargot for invasive predators—rats, Jackson’s chameleons, and the rosy wolf snail. According to Hayes, the remaining native snails have mostly been relegated to the few areas that still contain native forest, but even these refuges won’t last long if we don’t stem the tide of invasive species. Native snails dine primarily on the fungi that grow on native plants. Invasive plants change the way water moves through Hawaiian watersheds altering the ecosystem by changing what plants, animals, fungi or microbes can live there. The snails’ preferred fungi may not grow in altered habitats.

Pomaikai Kaniaupio-Crozier, conservation manager with PKW, is leading efforts to protect the Newcombia. With US Fish and Wildlife Service funding and partner help they are planning an exclosure in the native forest of West Maui to keep hungry predators from munching native snails.

The West Maui “snail refuge” will be modeled after similar exclosures on O‘ahu, where the O‘ahu Army Natural Resources Program has enclosed three areas to keep out rats, chameleons, and even the predatory rosy wolf snail. A 4-foot tall sheet metal fence topped by a curved lip deters rats and chameleons. Predatory snails face sheet metal at an impossible-to-scale 10 degree angle– if they do manage they hit an electric wire. One fence is equipped with an electronic sensing system that alerts managers via text message if debris falls on the fence.

The first step in protecting Newcombia is a population survey. “They are the size of a pinky fingernail and very cryptic,” says Kaniaupio-Crozier. “It’s like finding the needle in the haystack, looking for something that small in 8,600 acres. Up until a couple months ago we were getting pretty demoralized.”

Then they made a remarkable discovery. They found a new population, in totally unexpected habitat. The existing Newcombia population inhabited a wet area with lots of ‘ōhi‘a; the new population was found on ‘ākia, in much drier terrain. “There’s hope there may be another population somewhere else.”

From survey to construction, building the snail refuge will take several years. You can help. PKW is welcoming people interested in habitat restoration, monitoring, even joining in the brainstorming. Contact Kaniaupio-Crozier at pkaniaupio-crozier@mlpmaui.com or by phone, 870-4225. To learn more about the native and non-native land snails of Hawai‘i, contact Ken Hayes, khayes@hawaii.edu, Norine Yeung, nyeung@hawaii.edu, or visit the Hawaiian Land Snail Conservation Facebook Page.

As with many conservation projects, the snail exclosure at Pu‘u Kukui involves many agencies and partners: US Fish and Wildlife Service, National Science Foundation, University of Hawai‘i Mānoa, O‘ahu Army Natural Resources Program, Department of Land and Natural Resources, Plant Extinction Prevention Program, and more.

By Lissa Fox Strohecker. Originally published in the Maui News, July 14th, 2013 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.

The crown-of-thorns starfish–despite the prickly reputation, this species is native to Hawai‘i, and beneficial to the reef

Posted on April 15, 2013 by Lissa Strohecker 9 Comments

The crown-of-thorns starfish does munch on coral, but new research is showing that this species, native to Hawai‘i, benefits the reef. Photo courtesy of the National Oceanic and Atmospheric Administration[/caption]A single crown-of-thorns starfish is impressive. This unusually large, sinister-looking sea star grows to three feet in diameter with as many as 19 spiny arms. It’s hard to miss on the reef, where it munches on coral. Crown-of-thorns have the highest fertilization rate of any invertebrate: each female can produce up to 60 million eggs during a single spawning season. When too many of these survive, it’s considered an “outbreak.” An overabundance of crown-of-thorns can spell trouble for Pacific reefs. It’s an unusual case of a native animal acting invasively in the marine environment. But it’s not clear that all outbreaks are bad or how environmental changes might exacerbate the problem.

Proliferations of the spiny creatures can destroy 90 percent of a reef, as past outbreaks in Saipan, the Marshall Islands, and Guam have shown. In situations where the reef is stressed, an abundance of coral-eating starfish can trigger a cascade of changes. First the corals go, replaced by algal overgrowth. The resulting shift in fish populations can take years to recover. In Hawai‘i and Australia, concerns about crown-of-thorns outbreaks have focused on the reduced aesthetic value of the reef, and consequently, a decline in tourism. For some communities the reef is the icebox, and crown-of-thorns outbreaks can leave it empty.

But outbreaks rarely occur in Hawai‘i. Many crown-of-thorns starfish larvae die off, while adults are eaten by triton’s trumpet snails, stripebelly pufferfish, and harlequin shrimp. A healthy reef can support small numbers of prickly stars, and it’s probable that they benefit the reef in some way. According to Russell Sparks, aquatic biologist with the Department of Land and Natural Resources Division of Aquatic Resources, “In Hawai‘i, crown-of-thorns starfish feed on fast-growing, quick-to-settle corals, such as rice and cauliflower coral. These corals can overrun other species like lobe and finger coral, so a periodic bloom of crown-of-thorns could be an important way for reefs to maintain coral diversity.”

In 2004, marine biologists observed a crown-of-thorns outbreak in ʻĀhihi Kīna‘u. “Although the coral cover impacts were dramatic, the recovery seems to be well on its way,“ says Sparks. “It may increase overall coral diversity, which should make the reef more resilient to future disturbances.”

Until recently scientists hypothesized that crown-of-thorns outbreaks in remote locations such as Hawai‘i, Guam, and French Polynesia resulted from an influx of larvae from elsewhere in the Pacific. In Australia, massive starfish outbreaks spread south along the reef in waves, seeded from larvae upstream. But new research indicates that Hawaiian blooms occur within the native population. A team of scientists from the University of Hawai‘i-Manoa looked at the genetics of crown-of-thorns starfish and found that these supposed “invaders” were actually locals—they weren’t some rogue population from across the Pacific. What does this mean?

Crown-of-thorns outbreaks are not fully understood. The species may be acting invasively because of human interference. Some biologists theorize that heavy rainfall and coastal nutrient runoff contribute to a higher than normal survival rate for larvae, resulting in a larger number of adults. Over-harvesting of the species’ natural predators could be another potential trigger. Researcher Dr. Rob Toonen recommends that marine wildlife managers “seriously consider the role that environmental conditions and local nutrient inputs play in driving crown-of-thorns outbreaks.”

You can help scientists learn more. The citizen-monitoring project Eyes of the Reef relies on reports from regular reef users to monitor reef health. Crown-of-thorns sea stars are one species of focus. Early detection of outbreaks is critical to protecting the reef. Report any occurrence of 20 or more crown-of-thorns starfish through the Eyes of the Reef monitoring project at reefcheckhawaii.org/eyesofthereef.html

By Lissa Fox Strohecker. Originally published in the Maui News, March 10th, 2013 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.

Traveling by boat? Swab Those Hulls and Propellers to Stop Invasive Stowaways

Posted on January 18, 2013 by MISC Leave a Comment

Each year over ships make over 1000 trips to Hawai‘i. Container ships and barges, fishing boats, cruise

Organisms colonize an anchor chain. Photo courtesy of Hawaii DLNR-DAR

ships, and sailboats, aircraft carriers and military ships come bearing cargo for Hawai‘i or stop over on their way across the Pacific. Any of these boats could carry tiny stowaways from distant places, and that has resource managers concerned. Even an interisland boating trip could translate into trouble for your local reef.

“The majority of Hawai‘i’s aquatic invasive species came in via ballast water and hull-fouling,” explains Sonia Gorgula, the state coordinator recently hired by the Hawai‘i Department of Land and Natural Resources’ aquatic division to address the problem. Ballast water is taken by ships at sea or in port to maintain stability, and can contain organisms or larvae that may be harmful when released into a new environment, oftentimes thousands of miles from where they originated. Hull-fouling, or bio-fouling refers to the plants and animals that grow on any aquatic vessel, be it ship or yacht, dingy or dock. When these living organisms reach new waters, they can cause problems.

Of the two types of marine contamination, Gorgula says biofouling is the bigger worry in Hawai‘i. One species introduced this way is snowflake coral, a fast-growing soft-coral from the Caribbean. Since arriving in Hawaiian waterways, it has devoured the zooplankton that supports the marine food web and destroyed numerous black coral colonies. Hypnea, the rank invasive algae that washes up on Maui beaches, spread between the Islands attached to the underbelly of a fishing or sailboat. Hypnea is not only stinky and expensive to deal with on the beach, it outcompetes native limu.

Biofouling happens on any type of vessel, ocean or freshwater, that remains in port or dock long enough for organisms to become attached. “Broadly speaking it’s mussels, algae, barnacles,” says Gorgula. “When you start to see an assemblage become quite dense, you can even find crabs.” Boats function as floating reefs, transporting these aquatic aliens to Hawai‘i, where they may or may not find a home.

“Some species arrive and establish, then fail. Yet many species become invasive here that were not thought to be invasive until they get here,” says Gorgula. “Often there’s not enough information to predict what will become invasive.” One way to approach the situation is to treat all biofouling as harmful and focus on prevention—keeping boats with Hawai‘i on their itinerary free of small stowaways.

Biofouling is a drag, literally. Barnacles colonize the hull of a ship and reduce fuel efficiency as well as pose a risk of becoming invasive. Photo courtesy of Hawaii DLNR-DAR

Most commercial ships have incentives to keep hulls relatively free of growth; biofouling creates drag that reduces fuel economy. But other hidden “niche” areas underneath the boat—propellers and intake pipes used to pull in water for cooling the engine and fire-fighting—often house alien species. Cleaning the hull is part of regular boat maintenance; focusing on niche areas will help prevent the spread of hitchhikers. Certain paints are designed specifically to discourage fouling, and hidden spots can be painted as well as hulls, simple steps that feed into regular maintenance.

Policies and regulations for ballast water are well established worldwide, but biofouling has only received attention of recently. One of Gorgula’s tasks is to develop policy to protect Hawai‘i. “The biofouling policy issue is complex,” she says. “Around the world, only California, New Zealand, and Australia have developed policy. Globally, there aren’t many people working on it. We’re forging new territory” In 2007 the state legislature approved rules requiring ships planning to release ballast water to exchange the water first in the open ocean more than 200 nautical miles out to sea, reducing the likelihood ballast water will contain organisms that could find safe haven in Hawai‘i

It may seem trivial n a world of big ships and global transportation, but paying attention to the details can

A diver inspects a propeller for biofouling. Photo courtesy of Hawaii DLNR-DAR

make a big impact. Every boat, even those going interisland can help stop the spread of invasive aquatics. “Clean off biofouling in the same port where it accumulated,” says Gorgula. Be sure to clean your hull, anchor, props, bilge compartment, and any associated gear in the same watershed to prevent its spread to other watersheds and islands.

By Lissa Fox Strohecker. Originally published in the Maui News, January 13th, 2013 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/

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