Coqui Frog Pests in Hawaii

Coqui Capture: Need to nab an amphibian? There’s an app for that.

iPhones: not just for making calls anymore.

photo: josuha fletcher

It’s 1 a.m. and Edward “Butch” Porter is in a thick bamboo forest. He reaches for his iPhone, but not to call for help.  He’s zeroing in on his opponent and needs his secret weapon, an app dubbed the “Coqui Mimic.” He pushes a button, and a two-note “ko-quee” chirps from the speaker.

In 2010, after two decades in the tourism industry, Porter lost his job due to the declining economy. He’d been volunteering for nine years with a community coalition to keep the coqui-frog population out of his Kona neighborhood. With his savings dwindling, he started Kona Coqui Specialists, a business venture to help prevent total frog domination.

Coqui frogs (Eleutherdactylus coqui) are native to Puerto Rico and arrived in Hawaii—probably by hitching a ride in potted bromeliad plants—in the late 1980s.

The frogs have since been found on all six islands. Currently, they’re on Kauai and Maui, but are most widespread on the Big Island. On Oahu, they’re mostly found at plant nurseries, with recurring problems in Waimanalo.

Its nighttime mating call can reach 90 decibels, as loud as a lawnmower.

The frogs thrive in wet, warm environments, have no significant predators in Hawaii and eat native and non-native insects and spiders (thus possibly competing with endemic birds).

Early this year, Porter volunteered to hunt a frog on the Big Island. As usual, the frog stopped calling when he got close, so Porter blew a special whistle to beckon a response, a technique he’d pioneered. “My theory is that they feel threatened, and call back to me,” says Porter. Soon, he was staring into round eyes.

Bud Huff, an Apple application developer, happened to witness the man-to-frog conversation. Impressed, he emailed Porter a few sound files that mimicked the call. The two worked on revisions, tested them in the field and the app became available on iTunes in April, for $1.99. To date, more than four dozen copies have been downloaded. Porter doesn’t get royalties, and Huff doesn’t expect to make millions. Both simply hope to contribute to the control of coqui.

Currently, Porter is developing a library of coqui calls from individuals in different areas, which he believes vary in sound. “I spend a lot of time getting to know my enemy.”

If you think you hear a coqui, call the state’s toll free PEST hotline at 643-7378.

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A new book, Birds of Hawaii, New Zealand, and the Central and West Pacific, features more than 750 species in stunning detail, from the plumage of males, females and juveniles, to thumbnail maps showing where each species is found. Written and illustrated by Ber van Perlo, the guide also describes the birds’ songs or calls with attention to such subtleties as speed, tempo and pitch. The Akepa’s call, for example, is a “very high, fast tiritihi or tpeeh.” Because a lot of information is packed into 256 pages, finding Hawaii’s birds within the collection can be tough, and more in-depth narratives about their behavior would be nice. Overall, though, it’s a handy guide for those looking for concise information about bird species across these regions. Princeton University Press, $29.95.