Millions of tiny, shrieking frogs dominate the evening soundscapes of Hilo and Puna. With populations peaking at more than 20,000 frogs per acre, the non-native Eleutherodactylus coqui, or coqui frog, is reaching densities in east Hawaii not found anywhere in its home range in Puerto Rico.

Coqui are tree frogs native to the Caribbean. They were first introduced to Hawaii Island via imported nursery plants in about 1988. At that time, nothing was done to control the frogs, and their numbers and range increased. As populations reached unprecedented sizes in east Hawaii, the potential for spread to other parts of the island increased as well.

“We’ve learned that coqui frogs cannot migrate more than a few hundred yards, so if we can control the hitchhikers that come into our town from other places, we can keep them out of our community, as long as we act quickly,” said Kathy Rawle, Waimea resident and member of the newly formed Coqui-Free Waimea (CFW) group.

In North Kohala, a group of six local nursery owners along with other concerned community members banded together in 2003 to control an infestation of coqui frogs that had been imported to the district on nursery materials.

“We never spent the night at our nurseries, so we didn’t know that we had a frog problem until it was really bad,” said Kim Takata, founding member of the Kohala Coqui Coalition.

The infestation at the time covered an area more than 25 acres, including a steep stream gulch.

“From the very beginning, the community came together and were committed to the goal of keeping coqui frogs out of Kohala,” she said. They raised about $17,000, which was spent on supplies and equipment for control, as well as educational materials.

The process of controlling that first infestation involved repeated applications of hydrated lime, the approved treatment method at the time. “In took us 18 months, but we got rid of all the frogs, and we’ve kept them out of our community ever since,” said Takata.

A typical phone report to the Kohala Coqui Coalition hotline involves frog locations associated with new landscaping or recent construction, said Takata. Coqui frogs hide in potted plants, moist bags and boxes, and tag along on the outside of cars and construction equipment.

“In the past nine years, we have treated more than 200 separate sites in Kohala. If we hadn’t done this work, we would probably be just as infested as Hilo,” said Takata.

Similar community groups are organized and working together on coqui control in Volcano Village and Kaloka Mauka in Kona. Road signs remind residents of the ongoing efforts to keep the areas free of the pests.

The successful methodology employed in these communities’ efforts is two-pronged. First and foremost, the groups maintains a community hotline phone number and responds quickly to any reports of coqui. The Kohala coalition has two part-time paid staff who are experienced at locating frogs and spraying citric acid to control them, funded through donations from residents.

The groups also focus on education.

“Every coqui that ends up in Kohala was brought by a person, so a prevention program needed to change people’s behavior,” said Takata. “We encourage people to buy things like plants and flowers locally, because otherwise they may be infested with frogs.”

The success of community-based control programs in North Kohala, Volcano and Kaloko give hope to the newly formed Coqui-Free Waimea effort. “We are a self-help coalition of volunteers, and we are learning from other communities about how to successfully control coquis,” said CFW member Sherman Warner.

“The latest issue of the Honolulu Magazine said that the Big Island had given up hope of controlling coqui frogs,” said CFW volunteer Mary Hon. “That might be the view from Oahu, but we think we can make a difference for Waimea.”

The CFW group has held information sessions and neighborhood meetings over the past nine months to inform residents about coqui frogs, and engage support for their mission, to preserve Waimea’s quiet nights. The most recent meeting was held at Tutu’s House in Waimea on June 14.

Some Waimea residents in attendance at the meeting didn’t realize that coqui frogs had invaded their town. Malia Mangarin-Kitchen said, “If I hadn’t come to this meeting I wouldn’t have known there was spraying right in the middle of town last night. The information and stats about how fast coqui spread — we could have a big problem.”

Facts about the biology and ecology of coqui frogs were presented at the meeting by Raymond McGuire, vertebrate control coordinator for the Big Island Invasive Species committee. Coqui frogs differ from other frogs because they don’t have a tadpole stage, he said. They hatch as tiny froglets, and take about a year to reach sexual maturity. One female coqui frog can produce as many as 30 to 60 eggs a month, with about 90 percent survival of the offspring. One pair of frogs in the empty lot next door can quickly become a deafening chorus of hundreds of frogs in your neighborhood, he said.

“In Puerto Rico, coqui populations are naturally controlled by predators, disease, and parasites,” said McGuire. “None of those controls exist in Hawaii, so the frog populations are only limited by the amount of food available.”

CFW volunteers have been staffing an information table at both Foodland and KTA for the past year.

“People think that Waimea is too cold for coqui, but that’s not true,” said CFW volunteer Joyce O’Connor, who worked with her Vacationland neighbors to catch seven frogs. “They do get quiet in the winter, but they are still there.”

Coqui Free Waimea was granted $10,000 by the Hawaii Community Foundation through its Hoohui O Waimea grant program of the Richard Smart Fund in February, to fund both education and control efforts. More than 75 residents have signed up to assist the project, and the group has purchased a sprayer.

“We hope to spread the word that even though people have given up on controlling coqui frogs in some communities, it’s not a futile effort in Waimea,” said CFW volunteer Jeanne Oshima. “It’s only futile if we stop trying.”

If you live in Waimea and want to get involved, please contact your neighborhood volunteer coordinators:

Kamuela View Estates, Greg Paraiso at 253-8469; Waiaka/Akulani, Cherry Sanford at 650-862-7900; Puu Nani, Barbara Haight at 895-5513 or Steve Urbic at 747-0479; Iokua Place, Ann Lum at 640-4704; Laelae/Opelo, Bob Bonar at 769-2582; Vacationland, Cricket Higginson at 885-5311; Lakeland, Bill Lindsey at 896-5040. For other neighborhoods, call Jeannie Oshima and Tom Bailey at 887-1027. To report coqui frogs, email [email protected]. Tax-deductible donations are accepted. Make checks to Waimea Preservation Association, “for Coqui-Free Waimea” on memo line, P.O. Box 6570, Kamuela, HI, 96743.