Hawaii's Hated Frogs Tiny invaders raise a big ruckus
Puerto Rico's beloved mascot is a miniature tree frog named for its distinctive call: ko-KEE. All night long, choirs of love-starved males serenade would-be mates, who respond with quiet guttural chuckles. "To me, it's pleasant—just like birds singing," says Bryan Brunner, a University of Puerto Rico plant breeder in Mayaguez. "Here, everybody loves the coquies." And legend has it, he says, that coquies—native only to Puerto Rico—die of sadness when removed from their island.
Hawaiians are lamenting that that fable isn't true.
photo
TINY IMMIGRANTS. Adult coqui (left) and greenhouse frog (right) may be small, but their arrival in Hawaii has unleashed a big furor.
USGS/HEAR Project
In the mid-1980s, potted plants from the Caribbean began arriving in Honolulu carrying frogs. Some were 5-centimeter-long coquies (Eleutherodactylus coqui), and others, a quieter and even tinier cousin, the greenhouse frog (Eleutherodactylus planirostris). These stowaways reveled in their new setting: a largely amphibian-free land with a bountiful smorgasbord of insects, tiny spiders, mites, and other delectables—and no snakes, tarantulas, or other natural predators.
By the end of 1998, seven populations of coquies had established themselves on the Big Island of Hawaii, recalls Earl Campbell of the Fish and Wildlife Service (FWS) in Honolulu. And the number has rocketed. "We now have over 400 populations on the Big Island," reports Campbell, the FWS Pacific Basin coordinator for invasive-species issues. He also notes a few coqui outposts on Maui, Kauai, and Oahu.
Local wildlife-protection officials have no trouble recognizing new coqui populations. On the Big Island, public officials receive about 10 complaints a day from homeowners who, unlike Puerto Rican residents, get fed up with the racket, notes Tim J. Ohashi of the Department of Agriculture's Wildlife Services Branch in Honolulu.
A backyard full of the frogs can reach 70 to 90 decibels—the volume of moderate-to-heavy street traffic or the din in neighborhoods along aircraft takeoff and landing corridors. Indeed, 75 decibels is the maximum sound volume that people can encounter at work throughout their careers without risking hearing loss (SN: 5/22/82, p. 347).
Hawaiians aren't used to such nighttime noise. "Because we don't have lots of calling insects, if you go to where the frogs aren't at night, it's dead quiet," observes herpetologist William J. Mautz of the University of Hawaii at Hilo. "Then enter an area with a big infestation, and you hit this wall of sound."
But it's not only the noise that has federal officials up in arms. The proliferating coqui and greenhouse frog populations on islands that evolved in the absence of amphibians threaten to overwhelm native ecosystems. That's why USDA has teamed up with the State of Hawaii and FWS to control—and, if possible, eradicate—the tiny hoppers.
The scientists are developing tools, including caffeinated sprays and scalding showers, for holding back what they see as an advancing plague of frogs.
Hawaiians are lamenting that that fable isn't true.
photo
TINY IMMIGRANTS. Adult coqui (left) and greenhouse frog (right) may be small, but their arrival in Hawaii has unleashed a big furor.
USGS/HEAR Project
In the mid-1980s, potted plants from the Caribbean began arriving in Honolulu carrying frogs. Some were 5-centimeter-long coquies (Eleutherodactylus coqui), and others, a quieter and even tinier cousin, the greenhouse frog (Eleutherodactylus planirostris). These stowaways reveled in their new setting: a largely amphibian-free land with a bountiful smorgasbord of insects, tiny spiders, mites, and other delectables—and no snakes, tarantulas, or other natural predators.
By the end of 1998, seven populations of coquies had established themselves on the Big Island of Hawaii, recalls Earl Campbell of the Fish and Wildlife Service (FWS) in Honolulu. And the number has rocketed. "We now have over 400 populations on the Big Island," reports Campbell, the FWS Pacific Basin coordinator for invasive-species issues. He also notes a few coqui outposts on Maui, Kauai, and Oahu.
Local wildlife-protection officials have no trouble recognizing new coqui populations. On the Big Island, public officials receive about 10 complaints a day from homeowners who, unlike Puerto Rican residents, get fed up with the racket, notes Tim J. Ohashi of the Department of Agriculture's Wildlife Services Branch in Honolulu.
A backyard full of the frogs can reach 70 to 90 decibels—the volume of moderate-to-heavy street traffic or the din in neighborhoods along aircraft takeoff and landing corridors. Indeed, 75 decibels is the maximum sound volume that people can encounter at work throughout their careers without risking hearing loss (SN: 5/22/82, p. 347).
Hawaiians aren't used to such nighttime noise. "Because we don't have lots of calling insects, if you go to where the frogs aren't at night, it's dead quiet," observes herpetologist William J. Mautz of the University of Hawaii at Hilo. "Then enter an area with a big infestation, and you hit this wall of sound."
But it's not only the noise that has federal officials up in arms. The proliferating coqui and greenhouse frog populations on islands that evolved in the absence of amphibians threaten to overwhelm native ecosystems. That's why USDA has teamed up with the State of Hawaii and FWS to control—and, if possible, eradicate—the tiny hoppers.
The scientists are developing tools, including caffeinated sprays and scalding showers, for holding back what they see as an advancing plague of frogs.
