Eradicators concede Big Island to frogs
By Timothy Hurley
Advertiser Staff Writer
A $10.7 million plan to rid Hawai'i of its increasing numbers of noisy Caribbean frogs is being updated to acknowledge that eradication is no longer possible on the Big Island.
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"It's sad but true,'' said Mike E. Pitzler, state director of the U.S. Department of Agriculture's Wildlife Services branch. "This might be an animal we're going to have to live with.''
The notoriously noisy Caribbean frog, Eleutherodactylus coqui, is most prevalent on the Big Island but has also spread statewide.
Pitzler said the coqui frog and its cousin, the greenhouse frog, have tripled their range statewide in the past year. The tiny creatures have found habitats in 2,000 acres across the state.
The four-year eradication plan originally was written by Wildlife Services in 2001, but implementation was postponed because of delays in getting money. The plan describes an all-out assault on the frogs, with Wildlife Services joining other state and federal agencies to mobilize an army equipped with sprayers, vehicles and other equipment.
The document is being rewritten in hopes of obtaining about a third of the money — $3.5 million — later this year. Much of the plan hasn't changed, Pitzler said, though now it's being referred to merely as a "control plan'' because of the "astronomical'' numbers of frogs on the Big Island.
"There are some places on the Big Island where you have to plug your ears because it's so irritating and loud," he said. "You can see why people are distraught.''
Mindy Wilkinson, state invasive species coordinator, said that at last count there were 273 populations of coqui on the Big Island, with at least 23 populations on Maui, five on O'ahu and two on Kaua'i.
The frogs also have been found at a hotel on Lana'i and in a shipment of plants turned away from Kaunakakai Harbor on Moloka'i, according to Mele Fong of the Maui Invasive Species Committee.
Wilkinson said that while eradication is unlikely on the Big Island, there is still hope for the other islands.
"But unless people start to get moving, it's going to be hopeless on all the islands,'' she said.
Earl Campbell, Pacific invasive species coordinator with the U.S. Fish and Wildlife Service, stressed that safeguards must be maintained at the critical sites on the Big Island to keep the frogs from spreading further in nursery exports.
Campbell, who battled the Big Island frogs for nearly five years in his former job with the USDA, said scientists are seeing the impact on the environment. The frogs are preying on native beetles and crickets.
More could be done to knock the frog infestations back, Campbell said, but environmental regulations limit the techniques allowed. Under the Wildlife Services plan, readily available citric acid has replaced caffeine as the chemical of choice because of environmental concerns.
Wildlife Services officials are now testing equipment and application techniques as well as working on the environmental documentation necessary to put the frog-control plan into effect. The effort is being paid for with $200,000 obtained through a University of Hawai'i research program.
Pitzler said the agency was hoping to eradicate the frogs on Kaua'i, but workers found that the problem was worse than originally believed. The less noisy greenhouse frog was discovered on hotel grounds across the island, he said.
In their native Puerto Rico, Eleutherodactylus coqui live in densities of up to 8,000 an acre. Females can produce more than 200 eggs a year and reach sexual maturity in just eight months.
The Eleutherodactylus planirostris, or greenhouse frog, is about half the coqui's size.
Both species arrived in Hawai'i in plants imported from the Caribbean. It was most likely by hitchhiking in nursery material that the frogs spread from island to island.
Reach Timothy Hurley at (808) 244-4880, or e-mail at thurley@honoluluadvertiser.com.
