coqui frog — Maui Invasive Species Committee (MISC)

Haʻikū Residents bring back quiet nights through MISC Community Coqui Control Program

Posted on December 4, 2020 by Susan Frett

Haʻikū communities are taking back their quiet nights from noisy, invasive coqui frogs, with tools and training from the Maui Invasive Species Committee (MISC). MISC is currently working with five Haʻikū neighborhoods –Haʻikū Hill, Haʻikū Mauka, Haʻikū Makai, Lower Kokomo and Akoa/Ala Olu/Makaio. The program is ready to assist and empower more Haʻikū residents in the fight against this invasive species to protect their way of life and health of our native ecosystems.

Ha’ikū residents support each other in controlling coqui frogs on their properties with support from MISCʻs Community Coqui Control Program.

MISC recognized that in addition to strong support from the County of Maui and State of Hawai’i, containing and eradicating coqui in Haʻikū would require strong engagement at a neighborhood level. MISC launched the program to support and expand on existing community coqui control efforts by residents. MISC provides training, equipment, and citric acid solution (a food additive mixed with water). Community members provide boots on the ground – removing vegetation, hauling hoses, and dousing infested areas with citric acid solution. And it’s working. According to Haʻikū Hill team leader John Phelps, “Spraying each month has reduced the number of frogs on each property from hundreds to only a handful.” Neighbors working together can be more effective than independent control efforts, as coqui can quickly move into untreated areas or reinfest properties without a consistent effort. Participants report an additional benefit: the program is a good opportunity to get involved and meet their neighbors. MISC follows all social distancing and mask-wearing protocols whenever working in the community and all control work is conducted outdoors.

A Haʻikū residents sprays citric acid to control coqui on his property.

MISC provides different levels of support, depending on community need and participation. Individual residents can receive free powdered citric acid to control coqui on their property once MISC has confirmed that coqui are present. Residents can also borrow a 9-gallon walk-behind sprayer or a 100-gallon sprayer that fits in the back of a pickup truck. MISC provides training on how to effectively use the sprayers.

When three or more neighbors agree to work together across their properties, MISC provides a 100-gallon sprayer to participating residents every six weeks and helps residents with spray operations if needed. For larger groups of neighbors (at least nine committed households, plus a person who serves as a point of contact) MISC provides a reservoir of pre-mixed citric acid during the specified control week on a six week rotation. Participants report that having mixed citric acid in advance has been a “game changer” as it allows the team to focus directly on control activities. In two neighborhoods, the community groups proposed using a pipeline to effectively treat a larger area. MISC and the residents worked together to design and install the systems.

MISC provides a variety of sprayers to residents wanting to control coqui frogs on their properties.

Over the years, MISC has been able to eradicate 21 coqui populations on the island. Abe Vandenberg, MISC Coqui Field Coordinator, says the key to those successes has been persistence and consistency. He emphasizes the importance of community efforts, noting record levels of participation last summer, “Local engagement is a huge help to the island-wide coqui control strategy. As more community members help remove coqui from their own backyards, they allow MISC staff to take on more challenging work in the gulches and other areas with difficult access. Working the process of small wins will lead us toward the biggest possible success – a coqui-free Maui.”

For more information about the program, visit: https://mauiinvasive.org/community-coqui-control-program/
To get involved, call MISC’s Community Coqui Control Coordinator Susan Frett at 808-633-6646 or email skfrett@hawaii.edu.
To learn more about coqui, including environmental impacts, visit: https://mauiinvasive.org/coqui-frog/
To submit a report, visit: https://bit.ly/Coqui-Maui-Public-Report-Form or call MISC at 808-573-6472.

Social media posts help MISC catch coqui frogs

Posted on May 13, 2020 by Susan Frett 2 Comments

Hand captured coqui frog — Coqui frog captured by hand (example image from April 29, 2020)

Updated May 18, 2020

Late in the evening on May 12th, 2020 people across Maui started reacting to a video posted on Facebook of coqui frogs calling in the plants outside a large nursery in Central Maui. The notifications for the MISC Facebook page were flooding in as people sent messages, shared the video, and tagged MISC in their comments to the video on other pages. Many people also filled out the Coqui Report form on our webpage. Mahalo for all of your reports!

Early the next morning, before MISC could even start preparing to respond to the location, we learned that one of our awesome, longtime staff, Darrell Aquino, had quashed the outbreak! Darrell’s daughter, a former MISC Coqui Crew member, had seen the video on Facebook and let him know about it. Being a take-charge person, as well as an experienced MISC coqui field supervisor since 2005, Darrell went out to the location at 10:30pm on the 12th.

As all who watched the video that was shared or have heard coqui in person know, the males emit a loud two-toned call. By listening and whistling back to the frog, Darrell was able to track down and hand capture a single frog in the plants for sale outside the nursery. Additionally, Darrell learned from the local security person that the store manager captured a second frog.

Darrell sharing his knowledge with the coqui crew January 30, 2020

Mahalo to Darrell and the nursery store manager for their quick action! The area where the frogs were found is currently quarantined – plants are not being sold from there.

Mahalo to Darrell, and the nursery store manager, for their quick action! The area where the frogs were found has been treated with citric by HDOA and is currently being monitored throughout the evenings by store staff. Nursery employees will report any additional coqui frogs to HDOA who will respond if needed

Mahalo to the Maui community for taking action and drawing attention to this incipient invasive species threat. Unfortunately, other invasive species are not as vocal. We all need to be vigilant to limit the spread of all invasive species.

You can help! Prevent the spread of invasive species on Maui

Purchase locally-grown plants whenever possible – pest species hitchhike on cargo moving long distances.
Inspect all new plants and landscaping materials brought on to your property.
Isolate new plants and landscaping materials for a few days and inspect them again.
Do a self-test to inspect for little fire ants, check out this video to learn how.
Report MISC target invasive species
Support funding for more inspectors and rapid response at the county and state level.

Coqui calls on the rise

Posted on November 20, 2014 by Lissa Strohecker

A male coqui guards a clutch of eggs inside a pipe. With coqui populations on the rise throughtout the state there is an increased likelihood of coqui inadvertently reaching Maui. MISC file photo

The call of the lone coqui may not be increasing in volume, but calls reporting coquis on Maui are on the rise.

There’s been a dramatic increase in coquis arriving on Maui. In 2013, 25 Maui residents reported the presence of these noisy amphibians, almost double the reports from 2012 and 2011 combined. And the trend seems to be continuing for 2014, with reports of these invaders popping up in surprising places across Maui.

Coqui frogs are known to be in a handful of scattered populations around the island. According to the Maui Invasive Species Committee, all are under control and on target for eradication, with the exception of Māliko Gulch in Ha‘ikū. But the influx of new arrivals has the MISC crew concerned.

“We interview homeowners when there are new frogs reported, but we haven’t found any clear source of introduction,” said MISC Operations Manager Adam Radford. “In general, there are more frogs in the state than there used to be.” As coquis increase in number, particularly on Hawaii Island, so do the chances that the notoriously loud hitchhikers will spread elsewhere.

If you have heard a coqui, you know why they are not a welcome addition to your neighborhood. A single male frog has an 80- to 90-decibel screech, as loud as an alarm clock or freeway traffic. The frogs call from dusk until dawn. Coquis arrived in Hawai‘i sometime before 1988. In the absence of predators or competitors, their numbers ballooned, reaching densities exceeding 36,000 frogs per acre – two to three times greater than in their native range in Puerto Rico.

The coquis’ ear-splitting chorus may be the most obvious impact of this invasive species, but recent research suggests there are secondary, less-apparent consequences to allowing these quarter-sized pests to become established. Researchers have long known that coquis eat invertebrates such as insects, spiders and worms, but they recently discovered how these invasive amphibians skew the ecosystem in Hawai‘i.

What goes in must come out. The coqui frogs’ most significant change to the landscape is through the increased nutrient input from their droppings. While this sounds like a good thing, altering nutrients can create an environment more hospitable to non-native species.

This coqui was discovered by an observant Maui resident, hiding in a potted plant recently purchased from a garden shop. MISC file photo.

Researchers found increased leaf production rates in invasive strawberry guava in coqui-invaded sites compared to other sites. Plants native to Hawaii evolved in nutrient-poor conditions, so increased nutrient input favors non-native plants. Additionally, scientists found a greater number of insects in the order Diptera (flies) associated with coqui-invaded areas, the outcome of more excrement and more coqui carcasses.

Unfortunately, the coqui frog is widespread on Hawai‘i Island and cannot be eradicated. There, residents work together to control frogs in individual neighborhoods, and nurseries bathe plants at a hot water treatment facility before shipping stock off island. Barriers around parking lots prevent frogs from moving between cars and the areas surrounding the lot. But in the big picture, these stop-gap measures only will provide a temporary respite. We can prevent this from happening on Maui. With only one significant population in Māliko Gulch, land managers believe that the frogs can be eradicated, and new infestations thwarted.

You can help. Report coqui frogs to the Maui Invasive Species Committee at 573-6472. Support business and landscapers who take steps to prevent the spread of coquis via the plant trade. And, find a list of certified coqui-free businesses at coquifreemaui.org. For more detailed information about recent research on impacts of coqui, check out the coqui frog information page under priority pests at mauiinvasive.org.

By Lissa Fox Strohecker. Originally published in the Maui News, August 10th, 2014 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee

A most unwanted neighbor–coqui frogs

Posted on October 27, 2011 by Lissa Strohecker Leave a Comment

A coqui frog hiding on a landscape plant

A recent trip to Hilo highlighted the impact coqui frogs can have on our quality of life. It was not just the chorus heard throughout town and in my hotel room, but the fact that they could be heard while having dinner, enjoying a beach park and hiking through native forests. They’re everywhere. Recent estimates indicate that coqui have infested more than 60,000 acres of East Hawaii, from the ocean to 4,000 feet in elevation. With Hawaii County now planning to liquidate its coqui-control equipment, this noisy neighbor seems to have become a permanent resident on the island of Hawaii.

My work creates many opportunities to talk about coqui, and I am often asked why they are perceived as a nuisance in Hawaii when they are beloved in their native home of Puerto Rico.

One consideration is that they have no natural enemies here and can reach population densities more than twice that of their native range. This may cause significant problems for native insects (which they eat), change soil composition to the benefit of non-native plant species and compete with Hawaii’s native birds for food. Possible economic impacts in infested areas include diminished property values and sales, a change in the quality of visitor experiences due to their persistent nocturnal calls and decreased sales in the floriculture and nursery industry.

During my short visit to Hilo, I learned that a colleague with deep ties to Hawaii agriculture was facing the prospect of moving and foregoing personal professional opportunities, primarily because of the coqui. These experiences strengthened my motivation to keep coqui from becoming widely established on Maui.

Signage indicating the coqui-free status of a local business.

Coqui are believed to have been introduced to Hawaii by hitchhiking on plants or associated products in the late 1980s. Since then, coqui have shown up on most of the main Hawaiian Islands, in California, and Guam on plant shipments. This is still the primary avenue for dispersal, particularly from heavily infested areas. To help minimize the risk of introducing coqui to your neighborhood, the Maui Invasive Species Committee started a coqui-free certification program. The voluntary program encourages plant industry participants to adopt specific practices to reduce movement via the nursery trade. If you see a business designated as “coqui-free,” you can feel confident that you will not be purchasing coqui along with your plants or plant products.

Like the Big Island, Maui has coqui. Unlike the Big Island, Maui has only six infested areas, which cover an estimated 227 acres. Eleven population centers (areas with five or more calling males) have been removed since 2004. Five others have very low numbers of coqui. Really, only one substantial population remains. Maui has kept populations from becoming established by quickly responding to reports of new coqui locations. Although new introductions from infested areas are a constant concern for Maui residents, quickly identifying and capturing a few rogue males typically prevents a couple of coqui from becoming thousands. Left unchecked or unreported, coqui populations on Maui would be sure to rival East Hawaii at some point.

The author preparing a large-volume sprinkler for citric acid delivery.

In Haiku, for example, an area that once had low numbers of coqui has now spilled over into a steep-sided gulch. Efforts have begun to remove coqui from the 225-acre area by applying a 12 to 16 percent solution of citric acid (a food additive). But challenging terrain and trying to work at night (when coqui are most active) have demanded the development of creative citric application tools. These include fixed-line sprinklers, high-volume sprayers and even limited use of a helicopter in inaccessible areas. Although daunting, successful control efforts over the last four years have shown that the key to preventing coqui from permanently establishing is early detection of new locations, repeated systematic treatment of known populations and removal of frog-friendly habitat.

Unfortunately, even the combined resources of state and county agencies on Hawaii, as well as regular outings by community-based coqui control groups, have been no match for the coqui.

On Maui, we only have one large population left. We still have a strong chance to become and remain coqui-free. Please help by calling the Maui Invasive Species Committee at 573-MISC (6472) if you happen to hear a coqui frog.

More information about the coqui-free program can be found at www.coquifreemaui.org.

Adam Radford is the operations manager for the Maui Invasive Species Committee. He manages MISC’s efforts to control invasive plants, animals, and banana bunchy top virus.

Originally published in the Maui News, March 14, 2010 as part of the Kia‘i Moku Column.
You can find all the articles in the Kia‘i Moku series http://www.hear.org/misc/mauinews/

Haʻikū Residents bring back quiet nights through MISC Community Coqui Control Program

Social media posts help MISC catch coqui frogs

Coqui calls on the rise

A most unwanted neighbor–coqui frogs

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