Kia’i Moku Column — Maui Invasive Species Committee (MISC)

Illegal dumping risks spreading invasive species

Posted on September 11, 2018 by MISC

Coqui frogs, like this male guarding his eggs, take advantage of man-made materials for shelter. Illegally dumping rubbish can spread pests like coqui and make removing them more difficult. Photo by Maui Invasive Species Committee.

The evening of July 24, 2018, a Maui resident living near the Five Corners area of Haʻikū heard something she did not recognize as a normal sound for her neighborhood: the 2-note call of invasive coqui frogs. “I was in shock,” she says. “All the sudden there were 5-10 coqui frogs near my house.” She reported the frogs to the Maui Invasive Species Committee (MISC) and worked with neighbors to pinpoint the frogs’ location in a gulch adjacent to a nearby pasture.

When crews arrived a few days later, they indeed found coqui frogs spread across a quarter acre. They also found a rubbish pile with tires and plywood. “Given that there were no frogs, then suddenly ten—that’s too many to have jumped onto a car and been moved to the site,” explains Abe Vandenberg, MISC Coqui Coordinator. “The more likely scenario is that there was a clutch of eggs moved in the rubbish pile.” Coqui frogs hatch out from their eggs as tiny froglets, unlike other frogs that go through a tadpole stage that requires standing water.

Coqui are an introduced species to the Hawaiian Islands. Without the predators like snakes that keep them in check in Puerto Rico, they reach unnaturally high densities that are 2-3 times higher here in Hawaii than in their native habitat. In turn, they impact insect populations and nutrient cycling. But their mating call is what drives control efforts – males call “co-qui” from dawn until dusk in a piercing cacophony that disrupts sleep.

Unfortunately, the Five Corners situation is not unique. Even in the early days of coqui control efforts on Maui, roadside dumping factored into the amphibians’ spread. A vehicle abandoned in Māliko Gulch was the likely vector of frogs to a salvage yard in Haʻikū. As the coqui population increases on Maui, so do the instances of coqui moving in green waste and trash.

In the last year, illegally-dumped rubbish has been the vector for at least five introductions of coqui that MISC is aware of.

Little fire ants are another invasive pest that is known to spread through the movement of green waste and debris. Green waste facilities are monitored for these pests to reduce the risk of spread but illegal dumping can circumvent these safe guards. Photo by Maui Invasive Species Committee.

More often than not, the frog-infested trash is dumped in gulches – a difficult and dangerous place for crews to access and remove the noisy invaders.

It’s not just coqui frogs hitchhiking in trash and yard waste. On Hawaiʻi Island and in Tahiti and Guam, little fire ants have been spread through green waste. On Maui, MISC has worked with the owners of properties infested by little fire ants to address this threat, but undetected populations of pest ants most likely still exist. On Oʻahu, the larvae and eggs of the palm-killing coconut rhinoceros beetle (CRB) develop in coconut mulch, so preventing the spread of green waste is the most important task for crews working on the CRB Response Team. Coconut rhinoceros beetles are killing coconuts and other palms on Oʻahu and have not yet been reported from other islands.

Coconut Rhinoceros Beetles (CRB) lay eggs in mulch and so stopping the movement of infested debris is a priority for the CRB teams on O’ahu. Photo by U.S. Army Garrison Hawai’i.

When yard clippings and mulch are properly handled, green waste is less of a threat. The temperature of a managed compost pile reaches 150 degrees Fahrenheit, enough to kill weed seeds and many invasive pests and their eggs. Additionally, bringing green waste to a central location allows for monitoring. Green waste sites on Maui are regularly surveyed for the presence of little fire ants.

People who are tempted to dump their rubbish illegally may not realize that the impacts of their actions can be catastrophic. Often, illegal dumping attracts more dumping. The tangle of trash provides ample sites for pests to hide out and avoid treatment. You can help. Properly dispose of waste at the landfill, green waste facility, or compost it on site. Report illegal dumping to the Maui Police Department, at (808) 244-6400, and to the State of Hawaii Department of Health at (808) 984-8230.

Lissa Strohecker is the public relations and education specialist for the Maui Invasive Species Committee. She holds a biological sciences degree from Montana State University. Kia’i Moku, “Guarding the Island,” is prepared by the Maui Invasive Species Committee to provide information on protecting the island from invasive plants and animals that can threaten the island’s environment, economy and quality of life.

This article was originally published on May 13th, 2018 as part of the Kia’i Moku Column for the Maui News.

Introduced songbirds can be invasive in Hawai’i

Posted on August 15, 2018 by MISC

There are other birds not known to be on Maui that should be reported immediately if seen. The red-vented bulbul is one such species; — K. HARI KRISHNAN photo

In March of 2018, a cluster of reports from Maui residents and visitors of White-rumped shamas in West Maui came in on the online birding database, eBird. The Maui Invasive Species Committee and other organizations had received reports before, but the frequency of reports caught the attention of Chris Warren, who works with the Maui Forest Bird Recovery Project. These birds weren’t known to be widespread on Maui. White-rumped shamas are not native to Hawaiʻi. These introduced species have established breeding populations on Oʻahu, Molokaʻi, Lānaʻi, and Kauaʻi, but only scattered sightings had been reported on Maui in the past. No new invasive species is a welcome addition to our fragile ecosystems here on Maui. Warren and his team went to Kapalua and the Honolua area to investigate.

“Pretty soon it was evident that there were more than just a few birds out there,” says Warren. This wasn’t a case of a lone bird—the team found shamas in streambeds and forested areas from Napili to Honolua Bay, but the full extent of their population is still unknown.

White-rumped shamas are native to western Indonesia, southern India and southwestern China but have been introduced elsewhere as a result of their popularity as cage-birds and songsters. Here, their diet consists mainly of small insects that they pounce on while in the underbrush. According to Warren, there are other introduced birds that may pose a greater threat to native birds than the shama but what has resource managers concerned is that a bird new to the island went unreported for so long. “Our native birds are already at a tipping point, the last thing they need is another competitor,” he says.

White-rumped shamas are part of the host of bird species brought to Hawaiʻi during an era of bringing in song-birds. By the turn of the 20^th century, avian malaria and introduced predators had already brought native Hawaiian bird populations to low levels. Residential gardens were quiet but for the squawking of mynas and calling of doves. The socialites of Honolulu formed garden clubs for the purpose of importing song-birds—which only put added pressure on native ecosystems. From the 1920s up until the 1960s, when the practice was restricted, these garden clubs introduced many species of songbirds. Not all of these birds became established, but many did, and the musical White-rumped shama was among them.

Shamas were first released in Kauaʻi in 1931 and then in Oʻahu between 1938 and 1940. Those 89 birds then spread, reaching Molokaʻi in 1997 and Lānaʻi by 2009. They may have crossed between the islands on their own, but it’s also possible that humans helped them spread inter-island.

Warren and his colleagues are not exactly sure how far the shamas have spread on Maui. With the help of other resource management organizations, Maui Forest Bird Recovery Project is working to determine the distribution of these singing flycatchers. You can help!

White-rumped shamas are 9-11 inches long, about the size of a northern cardinal.
They have long tail feathers and spend much of their time in the underbrush.
Males have a glossy bluish-black back and head, a chestnut brown belly, and white patch feathers under their tail. Females have a tan head and back with chestnut belly.
Their song is impressive, both in range and volume, making them hard to miss.
Find information with photos and recordings, online: The Cornell Lab of Ornithology – White-rumped Shama. Report sightings, with a photo or recording through the online pest reporting system, 643PEST.org.

The red-vented bulbul is not known from Maui and should be reported immediately if seen. This bird resembles a cardinal but the head is completely black and it has a distinctive red patch on the underside. Bulbuls are serious agricultural pests on other islands. Report any sightings to 643PEST.org. — K. HARI KRISHNAN photo

While the white-rumped shama is likely here to stay, however, there are exotic bird species present on other islands that have not yet reached Maui. Red-vented bulbuls found on Oʻahu are one example: they are voracious fruit eaters and serious agricultural pests that quickly dominate the landscape.

To keep a new invasive species from becoming established, finding it early is essential. If you see something new in your yard, birds notwithstanding, take a few minutes to report it on the statewide pest reporting system. Either call 643-PEST(7378) or use the online report form, 643PEST.org.

This article was originally published on May 13th, 2018 as part of the Kia’i Moku Column for the Maui News.

Natural enemies could tame invasive Himalayan ginger

Posted on June 5, 2018 by MISC

Though not invasive in India where it is native, Himalayan ginger can completely transform a Hawaiian rainforest like it has in this section at 4,000-foot elevation above Haiku. Inset: Ginger fruits are spread long distance by birds and rats. FOREST and KIM STARR photo

The subtropical rainforests in the foothills of the Himalayan Mountains are amazingly diverse. In sections of India and Nepal, the forests are similar to Hawaiian rainforests in both temperature and rainfall-but the flora and fauna are radically different: this is the land of elephants and red pandas; 600 species of butterflies live here and over 400 species of orchids. But amongst the exotic plants there is one

The fruit of Himalayan ginger is a tasty treat for non-native birds, but this means the seeds are spread throughout the forest. Photo courtesy of Forest and Kim Starr.

that might be familiar to residents of Hawai’i-a yellow-flowered ginger that covers vast sections of Hawaiian rainforests.

Himalayan ginger, Hedychium gardnerianum, is native to the Himalayan foothills. There, it evolved over millennia supporting a diversity of species: the sweet nectar is a food for the long-tongued butterflies of the region and the plant lives in harmony with the species that surround it. Yellow flower stalks dot the landscape amongst hundreds of other orchids, gingers, ferns, and trees.

But in Hawai’i, Himalayan ginger dominates the landscape-growing fast and paving its way into the forest in an unrelenting march.

“Himalayan ginger displaces critical native vegetation layers, limits canopy tree recruitment, and hogs water resources in their massive rhizomes (roots). As it takes over and forms monotypic stands, it negatively impacts native flora and fauna, including Hawai’i’s unique arthropod complex and the Hawaiian honeycreepers,” says Alison Cohan, director of the Maui Nui Forest Program with The Nature Conservancy (TNC).

Introduced as an ornamental, Himalayan ginger escaped backyards and began invading rainforests of East Maui in the mid 1950’s. With seeds dispersed far and wide by birds and rats, the weedy plant spreads by leaps and bounds into the forest. Today, much of the mid-elevation rainforest of East Maui is a patchwork of native forest and alien ginger. But there is a lot left to protect: many ginger-free areas remain, including most of West Maui.

Ginger is a formidable foe and removing the plant is no simple task. Roots pave the forest floor like asphalt and every part of the rhizome must be removed. Bagged rhizomes take years to decay and if there is the slightest hole in the bag, hardy shoots emerge. If using herbicide, every portion of the root has to be treated. Plants on steep slopes and cliffs are inaccessible and impossible to remove until the weight of the water-logged roots causes entire sections to collapse in a landslide.

Why would ginger be a pest in one place but not another?

Djami Djeddour, weed biocontrol scientist with the Centre for Agriculture and Bioscience International, inspects a lone Himalayan ginger plant in India while searching for insects and fungi that live on the plant where it is native. These insects may be responsible for keeping the plant in check. DJAMI DJEDDOUR photo

The answer to that question is on the minds of resource managers in Hawai’i as well as New Zealand, Australia, and South Africa where the plant is invasive. With funding from organizations like TNC and the Hawai’i Invasive Species Council, research scientists traveled to India and collected insects and fungi that live on Himalayan ginger hoping to discover what keeps the fast-growing herb in balance there. An effective natural enemy could be a game changer for Hawai’i.

An effective natural enemy wouldn’t eliminate the plant, just bring it into harmony with the surrounding environment, much like it is in India and Nepal.

One of the most promising insects is a Cloropid fly that lives only on Himalayan ginger. The larvae live inside the stem stunting the growth and reducing flower production. Ginger natural enemies may be ready for release in New Zealand soon, promising progress for Hawai’i.

“The Nature Conservancy had been doing ginger work in Waikamoi for over 30 years, systematically conducting ginger control—containing the core population at the western edge of Waikamoi and eradicating outliers in native forest,” explains Cohan. Crews with Haleakala National Park work on the flowering pest in Kīpahulu Valley but the plant is widespread and thrives unchecked in wet places throughout the state.

There are ways you can help. Consider what you call the plant: though known for years as kāhili ginger, a pest destroying the rainforest does not deserve a moniker reminiscent of Hawaiian royalty much less one that might suggest that it belongs here. Perhaps call it toilet-brush ginger, as suggested by Pat Bily of TNC after years of removing it. Do not plant Himalayan ginger in your yard and remove it from your property before it spreads. Finally, participate in The Nature Conservancy’s quarterly volunteer trips removing ginger from Waikamoi Preserve. Contact hike_waikamoi@tnc.org if interested.

This article was originally published in the Maui News on April 8th, 2018 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.

The native dragonflies and damselflies of Hawaiʻi

Posted on May 18, 2018 by MISC

Megalagrion pacificum is an endangered damselfly found on Maui. Evolving over 20 million years of isolation, these native damselflies and dragonflies are threatened by habitat loss and introduced predators like mosquito fish. — U.S. Fish and Wildlife Service / DAN POLHEMUS photo

Twenty million years ago the Hawaiian Island chain was very different from what we see today. Laysan and Gardner Pinnacles were the prominent islands in the archipelago and the main Hawaiian Islands were merely raw lava flowing through the interior of the planet. Around this time a damselfly arrived to the chain, beating the odds in a successful journey across half an ocean.

This single event led to the evolution of some 26 species and sub-species of native damselflies in Hawaiʻi that exist today, according Dr. Dan Polhemus, the Aquatic Ecosystem Conservation Program Manager for the Pacific Islands Fish & Wildlife Office within the U.S. Fish and Wildlife Service. He has studied dragonflies and damselflies throughout the Pacific as well as here on Maui.

Perhaps our most spectacular native insects, damselflies and dragonflies were once widespread throughout the islands. Known as pinao in Hawaiian, these insects now exist only in a tiny portion of their historic range. Introduced predators and habit

at loss are to blame. Several species are so rare that they are listed as threatened or endangered. They are often extremely localized; some species are now only found in a single stream.

Pinao adapted to take advantage of the resources available in Hawaiian ecosystems. They live in a remarkable range of habitats, from mountain streams to marshlands and brackish anchialine pools.

Perhaps because streamflow is often intermittent, some species adapted to survive outside of streams and pools. There are naiads (larval stage of development) that take advantage of water seeps and pockets of rain that collect in the leaves of ʻieʻie vines. One species of damselfly is completely terrestrial – an adaptation existing in only a few other damselfly species in the world. Their young live in the moist understory of uluhe fern and lack gills found during other damselfly species’ naiad stages.

These hunters evolved eating small insects, both in the water and as they fly through the air. Today, pinao eat a variety of prey, including introduced insects such as mosquitoes. “They are essentially mid-air fighter planes,” says Polhemus. They hunt by folding their legs into a basket to snatch insects from the air. But these aerial predators are prey nowadays.

Lowland marsh and riparian areas have been converted and streams have been diverted. “Intermittent pools have a lot of invasive species,” says Polhemus. Without regular flow to flush out the introduced aquatic species, these pests, such as mosquito fish become established. While the handful of introduced dragonflies have fish avoidance behaviors, the native species, having spent the last 20 million years without predators, are easy prey for non-native fish and other insectivorous invaders. Like native birds in the face of tree-dwelling predators like rats, the larvae are easy picking for voracious mosquito fish. “Where mosquito fish are present, you don’t find native damselflies’” says Polhemus.

Bullfrogs and bulbuls (an invasive bird not present on Maui but found elsewhere in Hawaiʻi) also pose a threat to these ancient colonizers. Bullfrog tadpoles eat dragonfly naiads and bulbuls have been seen snatching the insects from the air.

Ants are another predator. The young naiads climb out of the water to morph into adults on land. Their skin splits open and wings unfold. As they wait for their skeleton to harden and wings to dry they are vulnerable to invasive ants.

There are several species of introduced dragonflies, and most of the dragonflies at low elevation are finddamselflies (distinguished from dragonflies by their ability to fold their wings back at rest) are now found mostly in upper elevations on the Hawaiian Islands, with two species found only on Maui. The largest dragonfly in the United States is found only in Hawaiʻi. Anax strenuus, the Hawaiian giant dragonfly has a wingspan of 6 inches.

You can help protect these unique animals: If you can no longer care for your fish or other aquatic friends, re-home them with someone who can. Never release them into the wild as they can cause ecological damage by pushing out native species, which play an integral role in a healthy Hawaiian ecosystem. Support legislation to maintain streamflow and prevent pollution. To learn more about these fascinating creatures visit: https://dlnr.hawaii.gov/wildlife/files/2013/09/Fact-Sheet-Odonata-damselflies-dragonflies.pdf

This article was originally published in the Maui News on February 11th, 2018 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.

A possible solution for the weedy tibouchina

Posted on February 13, 2018 by MISC

The upper elevations of the West Maui mountains are home to unique plants and animals found only here. Among them, species of lobelia and dwarf ʻōhiʻa. Tibouchina is one of the persistent threats to the survival of these rare species. Photo by Lissa Strohecker.

Tucked away in the rain and fog of the West Maui mountains are uniquely Hawaiian treasures: high-elevation bogs carpeted by rare and restricted plants. The last few hāhā (Cyanea magnacalyx) existing in the wild anywhere in the world are found there. Dwarf ʻōhiʻa, two unique silverswords, and many other plants are restricted to the high summit bogs and have adapted to the wet substrate.

Conservation crews monitor these bogs closely–they are in a section of West Maui that is fenced and protected from pigs, goats, and deer. Nonetheless pinhead-sized seeds of invasive cane tibouchina (Tibouchina herbacea) blow into the bog from the lower elevations and threaten the fragile ecosystems.

If crews did not remove tibouchina, it would take over the bog, crowding out the Cyanea and other endangered plants. It’s only in these ecologically sensitive bogs that crews remove tibouchina–there is simply too much of it on the surrounding slopes. As a result, it’s a continuous battle.

“Tibouchina is scattered throughout the 50,000 acre watershed of the West Maui. It’s found from sea level to the summit of Puʻu Kukui, but thrives in the wet windward slopes between 2,000-4,000 feet,” says Chris Brosius, manager of the West Maui Mountain Watershed Partnership. His crew helps to protect the bogs along with the rest of the watershed.

“West Maui is the steepest land area in the state, more dissected by cliffs than any other watershed in the Hawaiian Islands,” says Brosius. Even if they had the capacity, “We couldn’t possibly control this species everywhere it grows.”

Tibouchina thrives where there is soil disturbance–whether from pigs or the landslides that helped shape the West Maui’s. Tibouchina is often the first plant to arrive after a landslide.

Tibouchina belongs to the melastome family, a group of plants that are notoriously invasive in Hawaiʻi–miconia and clidemia are both melastomes. An ugly second-cousin to miconia, tibouchina is often leggy and scruffy looking. The leaves are two inches long, fuzzy, and lack the purple underside that characterizes miconia; the purple flower is pretty, but small–unlike the closely related glory flower.

A member of the melestome family, tibouchina is a notorious invader thatʻs past the stage of containment. Photo by Forest and Kim Starr.

Biologists first noticed tibouchina in 1977 on Big Island and in 1982 near Waiheʻe Ridge on West Maui. Within a few years it had spread throughout Maui, Lānaʻi, and Hawaiʻi Island. By 2005 it was found on Oʻahu, likely introduced on dirty hiking boots. It has shown up on Molokaʻi as well. As a trailside weed, it can be problematic–hikers passing through a patch of tibouchina end up coughing as tiny hairs are knocked off and the plant can be a skin irritant.

Tibouchina is native to Brazil. It can be difficult to find there–occasionally appearing in wet areas and meadows. It only reaches three feet in height and dies back every year. But here in Hawaiʻi, tibouchina can be 9-12 feet high. When last year’s growth dies back, the plant re-sprouts from the roots, creating bamboo-like thickets and taking over habitat for native species.

Why would the plant behave so differently here? One explanation is the lack of predation. Tibouchina evolved in Brazil alongside insects that munch its leaves, seeds, and roots. These insects are not present in Hawaiʻi, so tibouchina grows and spreads unchecked. One of tibouchina’s natural predators is a small beetle–both the larvae and the adults devour tibouchina leaves.

The beetle, called Syphrae uberabensis, can only survive by eating tibouchina and select other melastomes, none of which are native to Hawaiʻi. After 20 years of work collecting and evaluating the beetle’s impacts on other species in quarantine, US Forest Service scientists are confident that the beetle poses no negative threat and are preparing to release it into the wild.

An insect that relies on tibouchina for survival is in the final stages of evaluation for release in Hawaii. The syphrae beetle could make tibouchina less invasive. Photo by Forest and Kim Starr

The syphrae beetle could be what takes tibouchina down a notch–reducing the threat it poses to the remaining habitat of Hawaiʻi’s rarest native plants and animals. “If we don’t intervene, this species will continue to encroach on high-value native areas, erode biodiversity and spread elsewhere in the state,” says Brosius.

Tibouchina is just one example of a widespread pest with dramatic impacts. You can help by cleaning your hiking and hunting gear to prevent spreading hitchhiking pests.

This article was originally published in the Maui News on January 14th, 2018 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.

African Tulip Tree

Posted on January 31, 2018 by MISC

African tulip trees are a common sight along the Hana Hwy. Photo by Forest and Kim Starr

An African tulip tree in bloom is a remarkable burst of color. Consequently, the tree has earned many monikers: flame of the forest, fountain tree, and fireball. Scientists know it as Spathodea campanulata and this East African Native has been in Hawaiʻi for a long time. Renowned physician and botanist William Hillebrand first planted African tulip trees in Hawaiʻi in the late 1800s. Around 1915 Joseph Rock, another prominent figure in Hawaiian botany, introduced S. campanulata seeds collected in Java. In the late 1920s and 30s foresters planted and dropped African tulip seeds by air throughout many parts of the state. On Maui nearly 30,000 trees were planted. But as the “flame of the forest” spread and awareness of invasive species increased, people began to be concerned about the trees spreading.

We now know that African tulip trees are invasive and damaging to Hawaiian ecosystems. They grow extremely fast; in Puerto Rico they can increase 2” in diameter per year, shooting up from the forest floor and outcompeting other plants for sunlight. They can be a notorious pasture pest, springing up when land is cleared and creating a field of tulip trees with little else. Prolific seeders, their papery oatmeal-like seeds blow in the wind for miles. But perhaps what makes these trees most invasive is their shade-tolerant seedlings.

Shade tolerance means a seedling can sprout in an intact, shaded forest, then invade and dominate the landscape. This contrasts with many other invasive species that depend on disturbances and light gaps to gain a foothold. African tulip invades either way.

Given that African tulip seedlings can germinate and grow with little sunlight, they can creep into undisturbed forests and take over, growing faster than surrounding plants and expanding their domain. That is exactly what has happened along the windward slopes of East Maui. Beauty is in the eye of the beholder, and to those who know, the pretty, bright orange flowers ascending the hills above Hāna represent a garish plague. Potentially replacing ʻōhiʻa, ʻōlapa, maile and other native plants. The higher they go, the more likely they are to affect native forests.

The silver (or orange) lining to the presence of African tulip trees in our forests is currently limited in their ability to grow at high elevation. The flame of the forest peters out at around 3200’ elevation, near the boundary of the native dominated forest. The low-elevation forests where African tulip tree is found are already dominated by non-native plants, so the orange invader just dukes it out with other weedy pests.

Prolific seeders, these introduced species have invaded much of the low-elevation forests of Hawaii. However, they seem unable to grow at elevations above 3200′ in Hawaii. Photo by Forest and Kim Starr.

Near the border of the native forest though African tulip’s impacts are magnified. When possible, it should be removed. That is what Lance DeSilva with the department of Land and Natural Resources Division of Forestry and Wildlife is doing, both on Maui and Molokaʻi. In East Maui he’s decided to push back the upper elevation presence of African tulip tree by controlling the far-reaching plants in the Koʻolau Forest Reserve, particularly in and around Waihou Valley. “It’s my professional and personal goal to shrink the African tulip tree population of Koʻolau Forest Reserve,” says DeSilva. To date he and his team have removed over 650 trees. On Molokaʻi he’s taken out 48 trees along the north shore of Molokaʻi.

You can help. Don’t plant these trees, and if you already have them, consider removal. They are a particular hazard near homes and roads due to their tendency to drop limbs. For advice on removing African tulip tree, review the College of Tropical Agriculture and Human Resources’ handout on the Incision Point Application Technique: https://www.ctahr.hawaii.edu/oc/freepubs/pdf/WC-11.pdf.

This article was originally published in the Maui News on May 14th, 2017 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.

Drones help field crews find invasive species

Posted on November 22, 2017 by MISC

Would you rather walk across this lava field to look for invasive plants or search by air? Drones are increasing the efficiency of invasive species field crews on Hawaiʻi Island. Photo by T. Sullivan, BIISC.

Your mission: find a few invasive silk oak trees scattered across a 35,000-acre ancient cinder cone that resembles a bundt cake. Dead-ends and backtracking are the norm as you navigate up and down and across the slope, trying to locate and reach the trees.

Such is the task facing the crews of the Big Island Invasive Species Committee (BIISC) as they endeavor to control silk oak trees on the slopes of Puʻu Waʻawaʻa (literally translated to “many furrowed”) near Kona. They now have help from a set of eyes in the sky.

Using a drone, or unmanned aerial vehicle (UAV), the crews can find the best path across the landscape, saving time and allowing them to more efficiently do what they do best: get rid of invasive plants.

“It works best on a large landscape,” explains Timo Sullivan, BIISC’s early detection and remote sensing specialist. “You can trade 8 hours of hiking for 2 hours of controlling,” he says. Sullivan’s work with BIISC began a few years ago when they were exploring ways to identify invasive Australian tree ferns hidden within vast eucalyptus plantations. Today, the drone is almost a part of the field crew, scouting out the best route or even finding plants the crew is searching for.

Timo Sullivan uses drones to help the field crews from the Big Island Invasive Species Committee find invasive plants. Photo courtesy T. Sullivan, BIISC.

“It works best with species you can see above the canopy” he says. BIISC relies on UAVs to help survey for rapid ʻōhiʻa death, a fungal disease affecting ʻōhiʻa trees on Hawaiʻi Island. The main symptom: the leaves turn brown almost overnight, as though frozen in place. “It’s surprisingly hard to tell if a tree in the canopy is dead when you are on the ground,“ says Sullivan.

Typically, he arrives at a field site a few hours before the crew and spends an hour flying the drone, followed by an hour viewing the footage on the laptop. Then the crew can head straight to the plants on the ground. It’s possible for Sullivan to cover 40 acres in an hour. This is a big shift from the past efforts where crews spent all day hiking to find maybe 10 plants. “It’s been a huge morale booster,” he says. “Crews feel more successful when they can actually remove plants rather than search for them all day.”

The drone BIISC uses is nothing fancy, just a consumer model with a GoPro attached to record what’s seen. The footage can be reviewed on the spot or later. Instead of three sets of tired eyes scanning from a helicopter, the footage can be shared with many, including researchers looking at native plants or other aspects of the landscape. A manager can see what the crew faces, as well as document change over time.

The technology has limitations though: searching for plants under the canopy is still a task for ground crews, and the drone has to remain in the line of sight of the operator. Surveying in Kīpahulu valley while sitting miles away in Makwao is currently not possible.

Miconia (circled in red) has large leaves with a distinctive leaf pattern. Researchers at the University of Hawaiʻi are looking at ways to train computers to analyze drone footage to find miconia. Photo courtesy of T. Sullivan, BIISC.

Researchers are investigating ways to take drone usage to the next level. Roberto Rodriguez, a PhD student at the University of Hawaiʻi-Manoa is helping to determine the ideal speed at which to review footage. Heʻs researching computer programs that analyze the footage. “Miconia is a nice initial plant to work with,” he says. “The large leaf size and distinct vein pattern is something a computer could identify.” They researcher can then take what they learn and modify it for other species.

Ground crews can’t hang up their boots entirely. They can’t get ahead of an invasive species’ seeding cycle until they remove every young plant before it goes to seed—and small understory plants typically aren’t visible from the air. Drones are just another tool. There may come a day when crew each has its own drone, enabling workers to easily glance at a gulch or a steep, inaccessible cliff to make sure no invasive plants remain.

To learn more about research and drone usage for conservation in Hawaiʻi check out http://spatial.uhh.hawaii.edu/index.htm.

This article was originally published in the Maui News on April 9th, 2017 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.

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Parasite spread by cats threatens rare native animals

Posted on November 21, 2017 by MISC

As populations of invasive feral cats skyrocket in Hawaiʻi, so does the risk to native animal species.

The ʻalalā, Hawaiian crow, is so rare that it currently exists only in conservation breeding programs. Efforts to release the bird into the wild have been stymied by the presence of Toxoplasma gondii, a parasite spread by feral cats. Photo courtesy of USFWS.

The ʻalalā, or Hawaiian crow, is one of the rarest birds in the world. They are extinct in the wild, and only 114 birds are left in captive breeding facilities. The ʻalalā are protected from predators while they are in captivity. They are also protected from parasites found in the wild. These parasites are so widespread and persistent in Hawaiʻi’s forests that they may have interfered with attempts in the mid-1990’s to re-establish ʻalalā populations in the wild. Toxoplasma gondii, the parasite spread in cat feces, was found in five released ʻalalā, three died in the wild, a fourth died after being brought back to captivity. The fifth recovered after being treated for the parasite.

ʻAlalā are not the only animal in Hawaiʻi threatened by toxoplasmosis, the disease caused by the Toxoplasma parasite. Over the last 15 years toxoplasmosis has killed nene (our state goose) and other native forest birds.

Even marine mammals are at risk. Eight critically endangered Hawaiian monk seals and two spinner dolphins have died from the disease. The actual deaths of marine animals are probably higher; the bodies of marine mammals aren’t always recovered or tested for toxoplasmosis.

In 2015, a monk seal on Oahu died from toxoplasmosis infection. It is at least the eighth monk seal to suffer such a fate, a concern considering that the global population of these marine mammals hovers around 1,300.

The Toxoplasma gondii parasite can infect any warm-blooded creature, though the parasite’s life cycle depends on successful spread between cats and rodents, both of which are invasive in Hawaiʻi. Cats contract the disease by eating an infected rat; rats become infected when they come into contact with cat feces containing parasitic eggs. Once infected, the rats become risk takers – less fearful of cats and therefore easier prey — the cycle continues.

For about two weeks after infection, kittens or cats will shed microscopic toxoplasma eggs in their feces. These eggs can be infectious for months, even years under the right conditions. Animals ingest them through contaminated drinking water and meat, or when insects such as flies and cockroaches spread infectious eggs to food.

The population of feral cats on Maui is estimated to be between 300,000 to 600,000. Feral cats living along the coastline are a particular problem for marine mammals. On Maui, researchers estimated that the feral cat population around Kanahā Wildlife Refuge was at 1,100 in 2014. But wherever these feral felines are found (virtually everywhere on Maui – from the summit of Haleakala to the wettest rainforests down to the shoreline) feces can enter the watershed and wash into the ocean.

“The severity of the [feral cat] problem in Hawaiʻi is unlike anywhere else in country. On the mainland, growth of feral cat populations might be limited by extreme temperatures or the presence of larger predators, but here in Hawaiʻi they’ve found a paradise where populations can keep growing,” explains Joshua Atwood, Invasive Species Coordinator with the Department of Land and Natural Resources – Division of Forestry and Wildlife.

Humans are also at risk of contracting toxoplasmosis. An estimated 30-50 percent of the population carries the parasite, and infection generally occurs without any apparent symptoms. However, some groups are particularly vulnerable if they do become infected. Pregnant woman that become infected are at greater risk for miscarriage or premature birth. Babies can acquire the parasite in utero and can suffer eye or brain damage.

“The severity of the [feral cat] problem in Hawaiʻi is unlike anywhere else in country. On the mainland, growth of feral cat populations might be limited by extreme temperatures or the presence of larger predators, but here in Hawaiʻi they’ve found a paradise where populations can keep growing,”

Young children are also high risk: a child under three puts his or her hands or an object in his mouth every 2-3 minutes, imagine this child is playing in sandbox or at the beach near feral cat populations. Toxoplama parasites infect the brain, and though typically asymptomatic, toxoplasmosis infection can cause vision problems. Researchers are looking into links between toxoplasmosis and behavior change in people, including depression and schizophrenia.

You can help; keep your cats indoors to prevent transmission of toxoplasmosis. Spay or neuter any pet cats you have and if you can no longer care for them, please turn them over to the Maui Humane Society. If you have an unfixed cat, check with the Maui Humane Society. Several times a year they offer spay/neuter clinics free of charge throughout the island. Contact the Maui Humane Society for more details at 808– 877–3680 extension 3.

For more information:

Originally published in the Maui News on March 12th, 2017 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.

Read more Kiaʻi Moku articles.

Why All the Talk About Eradication?

Posted on August 17, 2017 by MISC

Test any material coming from an area infested with little fire ants. Preventing the spread of pests to new areas and finding infestations early is critical to achieving eradication. Photo by Masako Cordray

Life in paradise inevitably means dealing with invasive species in some form. From termites to rats, centipedes to garden weeds, there is an unending onslaught of pests we all deal with. Efforts to control them usually buy a temporary respite; we known and expect these pests will return.

Eradication, removing every last reproducing individual (or seed, in the case of plants) is the gold standard of invasive species management. In theory, eradication is achievable for any pest species, given enough time and money. In reality, time and money are in short supply. Deciding to eradicate a species is a significant undertaking, typically only possible when the target population level is low and accessible.

It took 80 years to eradicate feral goats from the island of Kahoʻolawe but today the island is recovering.

Goats once ran rampant on Kahoʻolawe. Introduced to the island in 1793, a gift to Chief Kahekili of Maui from Captain Vancouver, these hearty hooved beasts quickly took over, limited only by food availability. They devoured the vegetation on the island, threatening native species and exacerbating erosion. Starting in 1910, a host of assorted land managers, including ranchers, the military, and the state government battled goats on Kahoʻolawe. Over a period of 80 years goats were hunted aggressively—but always a few remained, too difficult to find. When control would cease, goat populations would explode again.

The last goat was finally removed in 1993 that goats were truly eradicated from the island. Those last few goats were the hardest to find, yet tracking down the holdouts was critical to the island’s vegetation recovery. As was the case on Kahoʻolawe, persistence is often a key ingredient of successful eradication efforts.

“It’s easy to kill 99% …. It’s the last 1% that makes it tricky,”

Not just large invaders can be eradicated—little fire ants, for example, are eradicable. These miniscule ants have something in common with the goats that once riddled Kahoʻolawe: removing the last few is the most challenging yet most important part of the job.

Until Hawaii Ant Lab arrived, attempts at eradicating the tiny ground and tree-dwelling little fire ant had failed. Getting a bait to the queen is part of the challenge, one met by their research and expertise. Photo by Masako Cordray

“It’s easy to kill 99% of the ants. It’s the last 1% that makes it tricky,” says Cas Vanderwoude, manager of the Hawaiʻi Ant Lab. His organization provides the expertise behind the efforts to eradicate little fire ants from Maui. And, as with any attempt to truly eradicate an invasive species, most of the work lies in finding the last few. “Surveys are essential to understanding where the ants are, how effective the treatment is, and if the population is eradicated.” Currently, MISC and the Hawaiʻi Ant Lab anticipate that infested properties will be monitored indefinitely to ensure the little fire ant has been eradicated.

The fact that these tiny invaders also live in trees adds to the challenge. Historically, treatment of the little fire ant relied on granule pesticides developed for fire ants in general. These granules could only be scattered on the ground and did nothing to control the colonies of ants living in trees. In Hawaiʻi, worker ants find enough food in trees, relying on sap sucking insects and other food sources, never needing to forage on the ground. Without workers carrying bait back to the queen in the nest, the colony will survive, reproduce, and reinvade, as the goats of Kahoʻolawe did time and time again. Fortunately, the Hawaiʻi Ant Lab has developed techniques for controlling little fire ant on the ground and in the trees.

Little fire ants seen on a taro leaf for scale. These tiny terrors have huge impacts. Photo by Masako Cordray

On Maui there are only a handful of little fire ant populations: Nāhiku, Kapalua, Huelo, and Waiheʻe. Though eradicating these infestations will be a challenge, complete removal of the little fire ant from Maui is the goal thanks to the expertise of the Hawaiʻi Ant Lab.

Eradication is time-consuming and expensive, though the price is negligible when compared to the never-ending cost of suppressing these pests so we can continue to enjoy life in Hawaiʻi as we know it. Economists estimate that the cost of damage from little fire ants on Hawaiʻi Island will exceed $140 million if current trends continue.

Eradication is costly, but it is an investment in the future. You can help to keep little fire ants at bay by ensuring you do not have any present on your property. Survey your yard for the little fire ant. Quarantine and test potted plants, mulch, and soil before distributing it on your property. Find testing information online at stoptheant.org or littlefireants.org

Originally published in the Maui News on January 6th, 2017 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.

Read more Kiaʻi Moku articles.

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A little love for all the non-invasive species in Hawaiʻi

Posted on February 14, 2017 by MISC

ʻŌhiʻa ʻai, mountain apple, is an introduced species and one of the thousands of plants in Hawaiʻi that are harmless. Photo by Forest and Kim Starr.

The vast majority of introduced plants stay in the gardens where they are planted. Without their native pollinators or preferred climate, their survival and spread depends on humans. Our careful maintenance keeps them going. Take breadfruit and citrus trees—they flower and fruit in Hawaiʻi, but can’t set seed and therefore don’t spread in the wild. If you want these plants, you have to cultivate them.

A small subset of introduced plants spread without human help. “Of the roughly 12 to 13,000 non-native plants present in Hawaiʻi, only about 12% have become naturalized, or have formed self-sustaining populations in the wild,” explains Chuck Chimera, the Weed Risk Assessment specialist with the University of Hawaiʻi.

Plumeria is one of the 12-13,000 plants introduced to Hawaiʻi. Plumeria do not produce seed and therefore never escaped cultivation. Photo by Forest and Kim Starr.

Naturalized, non-native species are those we regularly see hiking or driving down the road; they are the plants in the unmanaged parts of the land; spreading without our help, forming self-sustaining populations that will persist year after year. Sometimes, we take notice of them: like a mountain apple along the roadside. Sometimes we overlook them, like self-heal, a small, purple flowered plant in the mint family – it grows from the lowlands to around 8000ʻ, given enough water.

ʻŌhiʻa ʻai flowers in the forest are a sight to appreciate. Photo by Forest and Kim Starr.

Introduced plants or animals often provide a service to us or to the environment: Cook pines collect water from passing clouds, sweet potato and citrus fill our bellies, wild hives of European honeybees pollinate our gardens, and red-billed leothrix spread the seeds of native plants.

Self-heal, Prunella vulgaris, is a common introduced plant in Hawaiʻi. Photo by Forest and Kim Starr.

It is only tiny subset, roughly 1% of all the introduced species, that spread aggressively and outcompete native Hawaiian plants. Capable of transforming our ecosystems, these are the invasive species that land managers battle. Miconia, fountain grass, little fire ants, and strawberry guava are among the most notorious. While these bad actors get a lot of attention, most foreign introductions are benign, and even provide benefits to us.

Take time to appreciate the beauty and savor the tastes of all the introduced species that abound. A Valentines bouquet of locally grown flowers, a meal of fresh fish on a bed of locally grown greens, haupia for dessert. Support your neighborhood farmer or flower grower at a farmers market or grocer. Doing so helps prevent the accidental interisland spread of hitchiking pests like little fire ants or coqui frogs.

Please make wise planting decisions; check before you plant. The Weed Risk Assesment is 95% accurate at predicting the liklihood of a plant becoming invasive in Hawaiʻi. Check it out at plantpono.org

Originally published in the Maui News on February 12th, 2017 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.

Read more Kiaʻi Moku articles.

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