Noisy Frogs Plague Hawaii

H O N O L U L U, Dec. 28, 2000 -- Larry Stevens lives in a secluded rain forest onthe east side of the Big Island, a quiet spot where he once enjoyedthe peaceful, gentle sounds of nature.

But Stevens hasn’t had a good night’s sleep in months. Noisytree frogs have invaded the Hawaiian Islands, and have spread soquickly that state and federal officials say there’s little theycan do.

“You’d never believe so much noise could come from a creaturethat small,” said Stevens, a 51-year-old social worker.

Carried by Potted Plants

The cute green frogs, the size of a dime to a quarter, arrivedin shipments of agricultural goods, possibly in potted plants,researchers say.

Instead of croaking, they chirp — loud and often. Individualmales have piercing chirps that reach as high as 90 to 100 decibelsfrom a foot and a half away. That’s comparable to a lawn mower,table saw or helicopter, according to the University of Hawaii’sSpeech Pathology and Audiology department.

The frogs were first noticed in the mid-1980s in ruralCurtistown on the Big Island, but have since spread to parts ofOahu, Maui and Kauai.

From a dozen population sites early last year, the frogs havespread to 150 places on the Big Island, and the state has set up ahot line where residents can call to report their appearance.

Flourishing in New Home

Mindy Clark, an orchid farmer in Curtistown, said she has toclose her windows since the frogs “infiltrated” her neighborhood.

“Soon as it gets 5:30 [p.m.] they’ll start chirping,” Clarksaid. “And they’ll go real strong till midnight.”

They don’t create a major problem in their native Caribbean,where natural predators control their population. But with anexponential reproduction rate and no enemies other than angryhumans, the frog population in Hawaii has exploded.

In some areas, there are more than 8,000 frogs per acre.

“The sheer number here is the big difference,” said EarlCampbell, of the U.S. Department of Agriculture’s National WildlifeResearch Center.

Tiny Frogs Cause Big Problems

Besides being a nuisance, the frogs compete for food with nativebirds and wildlife, he said. The frogs can consume as many as46,000 insects per acre every night.

“There is a grave concern this could be a big problem,”Campbell said.

Fred Kraus, the alien species coordinator for the state landdepartment, said the frogs may threaten the isle economy bybothering tourists at hotels, lowering property values andinhibiting the export of tropical produce and flowers.

“People are annoyed as hell,” Kraus said. “We got a lot ofcomplaints from residents. Some threatened to leave the state.”

One woman has reported that her health has failed because thefrogs keep her up at night. Other residents said they can’t movebecause they can’t sell their home.

Killing With Caffeine

Campbell, who heads a field research station in Hilo, has beenworking with the state to experiment with a pure caffeine spray tocontrol the frog population.

It is presumed the pure caffeine causes the frogs to go intocardiac failure. It is not believed to be harmful to humans, nativeplants and wildlife, but the effects are still being studied.

Researchers said the trials look promising, but must be approvedby the federal Food and Drug Administration, and that could takemany months while the frog population and noise grows and spreads.

Roundups Futile

Residents have tried neighborhood roundups, but “they’re notmaking a major dent,” Campbell said.

Stevens said he and neighbors went out three nights a week armedwith a ladder, flashlights and plastic bags to catch frogs.

“We were elated, we got them all and had them eradicated in ourneighborhood, but within four months we had an explosion,” hesaid. “We mobilized more of the neighborhood, but by that time itwas hopeless. There was just too many. The eggs hatched. Nowthey’re out of control.”