By William Booth
Published: Gulf News
Dubai, U.A.E.
May 18, 2001
Tabloid issue
"Helllloo? It's Nilton, with the ag department? Coming to look for frogs?" he calls out, taking care that he and his guest are not shot as backyard prowlers. The chief of chemical and mechanical control is carrying a large glass jar. "Oooo, he's a loud one, eh?" Matayoshi says, impressed. Now he is close, real close. The frog's call grows as urgent as a lifeguard's whistle, and as relentless as a toddler with a question. Matayoshi sweeps his flashlight's beam up into the tall ginger by the lanai. There's something moist and brown in the bushes.
Hawaii has been invaded by a dun-coloured, two-inch-long, cute little frog native to Puerto Rico, called Eleutherodactyluscoqui, or coqui for short. The name mimics the frog's two-not chirp--ko-KEE!"a trilling love song that has been described in the scientific literature as sounding like a car alarm. There are thousands of them, maybe millions, in Hawaii. They do not belong here.
Beloved as a cultural mascot in Puerto Rico, where the cartoon coqui adorns ashtrays and shot glasses for sale as keepsakes, the uninvited frog was condemned as an official pest in Hawaii last year.
The coqui represents a major potential disruption of the ecosystems of Hawaii. There are no naturally occurring reptiles or terrestrial amphibians, no snakes, iguanas, toads or salamanders in Hawaii. Until the coqui arrived, it was a frog-free world.
The problem with adding frogs to the system is their voracious and indiscriminate appetite. Not only do the coqui consume insects that are necessary for pollination and other ecological chores, but the foreign frogs directly compete with native birds or insectpreybirds that are already increasingly rare.
Apparently, there are only so many bugs to eat in Hawaii. Then, there's the noise.
Hawaiian nights are renowned for their gentle lulling calm. Guests at Maui resort hotels infested by coqui now check out of their rooms early because the shrieking frogs make it impossible to sleep. "It apparently was driving them crazy at the Ritz-Carlton," sad Kristy Martin of the Maui Invasive Species Committee. At one point, a hotel was paying bounty hunters $75 a frog, dead or alive.
The coqui's call has been measured at 90 decibels, roughly equal to a lawn mower's racket. The call is so persistent, so urgent, that a Honolulu dentist confessed to Matayoshi that a single frog's night song was making him "nuts".
No state in the nation lies more exposed to the dangers of invasive species than the biologically rich but isolated islands of Hawaii, which have been combating alien plants and animals for more than a century.
Unfortunately, the exceedingly tough challenges facing Hawaii are not unique, and there is increasing concern among scientists that alien invaders in the newly global economies pose an accelerating threat to ecosystems around the world, from the last tracts of tropical forest on Oahu to the corn belts of the Midwest.
The tale of the coqui suggests why.
Researchers suspect that the first frogs arrived on the islands in the early 1990's, hitchhiking on a shipment of nursery plants. The international horticultural trade today represents one of the easiest routes for the spread of invasives.
A very nice, wet bromeliads may very well have provided the pioneer frogs with a first-class ticket to paradise. The frogs first appeared at seaside luxury hotels.
When Earl Campbell, the invasive species coordinator for the U.S. Fish and Wildlife Service, surveyed the coqui populations on Hawaii in 1998, he and his colleagues could document 10 sites infested by frogs. Now? Campbell reports there are at least 260 known coqui sites on the Big Island of Hawaii alone; more than 40 sites on Maui; 20 on Oahu; and at least two on Kauai.
Campbell suspects the frogs are moving around with the help of humans, in loads of plants and perhaps intentionally. "When it's one or two frogs, the sound can be pleasant," he said.
With no natural enemies, the frogs multiply with gusto. At a single site on the Big Island of Hawaii, Lava Tree State Park, the population is estimated to exceed 20,000 individuals an acre.
"It is almost indescribable," said Robert Sugawara of the U.S. Department of Agriculture's Hilo Field Station on Hawaii. "They're pretty much out of control."
Everyone agrees that they should have attacked the coqui immediately upon its arrival, before it spread from island to island. But by the time government agencies acquired funding and were ready to act, the plague had begun. So, what to do now about the coqui?������
Officials are considering the use of hydrated lime, a soil fertilizer that essentially "dries" the frogs to death. But the EPA has refused to approve its use as a frog killer.
On a smaller scale, of course, there is always hand-hunting, which is how Nilton Matayoshi has spend the last year capturing 40 frogs.
Near the end of his night shift, Matayoshi drove by a Home Depot near downtown Honolulu where he had heard frogs singing before. It did not take too many minutes watching Matayoshi on his hands and knees, stalking a calling male amid the golden pathos plants, to realise that this was not going to be an easy victory.
"Got him!" Matayoshi ran with his closed fist to the truck, got out his glass jar, thrust his hand inside and opened it. Leaves. Behind him, the coqui began to sing again.