SIDE EFFECTS; A Frog Brings Cacophony to Hawaii's Soundscape

When is a frog like a banjo? When it ends up in Hawaii without the rest of the band.

Consider the coquí, a small frog native to Puerto Rico, where it seems to fit right in with all the other frogs and the sounds of the semitropical Caribbean.

''It is a very popular creature throughout the island and enlivens the evenings with its timid ko-kee from which it get its name'' according to a Web site that promotes the wonders of Puerto Rico (www.welcometopuertorico.org). Switch to another ocean, and the ko-kee is no longer timid. ''Since becoming established in Hawaii in the late 1990's, incredibly loud choruses of this medium-size Puerto Rican frog have been disturbing the sleep of Hawaiians, who have enjoyed frogless nights throughout recorded history.''

That comment comes from the Institute for Biological Invasions. But even considering the sources, this seems a wide gap in perception.

The reason is that the frog, Eleutherodactylus coquí, is that familiar ecological villain -- an invasive species. Hawaii has no native amphibians or reptiles so the frog, about an inch and a half long, can flourish and disrupt the balance of species without any natural restraints.

And, at least in the human view, the coquí is also disturbing the balance of the soundscape. The mating calls of the coquí, which can be heard on the Web site of Hawaii Ecosystems at Risk, www.hear.org, is something between a chirp and a smoke alarm. It can reach 100 decibels -- similar to a loud car horn -- at a distance of a foot or two.

The mayor of Hawaii County, which consists of the Big Island of Hawaii, recently asked the state for emergency funds to use lime and citric acid spraying to kill the frogs.

This may seem harsh. But anyone who has been forced to listen to someone else's music blaring from a boom box or a car window should be able to understand. Nature has its own music, which undergoes extreme changes from place to place. The desert and rain forest are as different as Metallica and Caetano Veloso. And, at least to the ears of humans, places have their own musical ecology.

People become accustomed to the sounds of nature they know, a certain orchestration, a texture. Frogs, many different frogs, are part of the sound of the Caribbean. They may be loud, but the sounds of one frog are balanced by another.

Spend a night in the Okefenokee and you'll be treated to some of the loudest frogs you'll ever hear. But the sounds blend together. They're satisfying. Put a pig frog under your bed at home and you would be awake all night.

In musical terms, the coquí might be a banjo in a bluegrass band, balanced by guitar, bass, fiddle and mandolin. There are those who believe nothing balances out a banjo, but these are people who don't like bluegrass music at all.

Imagine a land where bluegrass music of any sort was unknown. (For those who would like to move there, this is a fantasy.) What if that peaceful land were invaded by banjos, and banjos alone. Suddenly the night would be filled with banjo music. No guitars, no fiddles, just banjos. Spraying with lime and citric acid suddenly makes sense.

I happen to be a big fan of frogs, but then I live in the Northeast where spring peepers are a brief seasonal pleasure. I also try to play the guitar with a banjo player and a mandolin player, who have recently instructed me to work on my bass runs to balance out the two tenor instruments. I've been practicing hard, but calling a banjo a tenor instrument hardly does it justice. So, as much as I love frogs, and banjos, I feel for the people of Hawaii.

I would suggest that we drop this whole conceit of invasive species, as if frogs and beetles and northern snakehead fish were meeting in secret cells, planning how to penetrate our borders and then drive us all mad by making noise and eating defenseless North American fish.

These problematic species are accidental tourists stranded in a strange land. We're the ones who carry them around and dump them where they can cause problems. Frogs do not plot invasions.

I suggest we call them dissonant species. That leaves out the implication of intent, but gets across what happens to the complex arrangements of the natural world. It also leaves open the possibility of a new sort of fusion ecology, or atonal environmental music.

People, certainly, are happy to accept some new species.

The northern snakehead has been a headline favorite. But did any newspaper ever carry a headline decrying the German brown trout, an introduced fish, and a fierce predator that eats its own young? But then we like trout. And they are quiet.

If trout sing, few people have heard them.