3-year Big Island study
to look at coqui habitat

HILO » The Big Island's shrieking coqui frogs seem to reach their maximum numbers when they live in non-native albizia forests, University of Hawaii-Hilo biologist William Mautz says.

Mautz has been granted $300,000 from the National Science Foundation to do a three-year study of whether the frogs do better in a native Hawaiian forest of ohia trees or among non-native albizias.

Mautz is betting on the albizias since they are "nitrogen fixers" which make natural fertilizer, so everything in the food chain that grows with albizias could get a boost, including the frogs.

A specialist in amphibians and reptiles, Mautz will also study the effect on forest ecology of thousands of coquis per acre gobbling up every insect, spider and other small, edible creature.

He will be assisted by UH-Hilo biologist Rebecca Ostertag, biologist Paul Klawinski of William Jewel College of Missouri, and ecologist Flint Hughes of the U.S. Forest Service.

Working with UH-Manoa biologist Arnold Hara, Mautz learned in 2002-2003 that coqui concentrations on the Big Island can reach 12,000 per acre. That means for anyone walking through an infested forest, there might be as many as three coquis underfoot in every square yard of ground, Mautz said.

The idea that albizia forests make an especially good home for coquis is just a "casual observation," Mautz said. The purpose of the study will be to see if the observation is accurate.

The exact design of the study is under review, since Mautz only got half of the $600,000 he requested from the National Science Foundation. With half the funding, "it's a real challenge," he said.

The study, which will probably start this summer, will involve monitoring two areas of albizia forest, one with coquis and one without, and two similar areas of ohia forest.

Mautz is hoping that a Hawaii County request to the Legislature for $2 million to fight the coquis will result in a portion of that money coming to supplement his study.

Eradicating coquis is not the direct intent of the study, but researchers could learn facts that will be useful in controlling or eradicating the frogs, he said.

One question is what happens during dry spells, when frogs go quiet. They quickly return to their normal volume of noise when rain comes again.

Although some people consider the loud, high-pitched mating call of male coquis to be pleasantly musical, most Big Islanders familiar with it hate it.

Mautz opposes their presence in Hawaii because they appear bad for the environment. They might eat spiders that control mosquitoes, and they might eat bugs that birds need, he said.

But the big worry is the enormous amount of food that the frogs would represent to snakes, if snakes ever got established on the island.