NEW TECHNOLOGY TO CURB INVASIVE COQUI ON OʻAHU

Drones will control frogs found at higher elevations in the Koʻolau Mountains

News Release from DLNR, Sept 25, 2024

(HONOLULU) – Invasive coqui frogs have been found at higher elevations than previous infestations on Oʻahu. The Department of Agriculture confirmed in June, following a report from a citizen, the distinctive chirp of the coqui roughly 200 meters below the summit of Kuliʻouʻou Ridge Trail on the leeward side of the mountains. Surveys were subsequently performed by the DLNR Division of Forestry and Wildlife (DOFAW), and the Oʻahu Invasive Species Committee (OISC).

It is estimated that 13 acres of forest are infested below the Kuliʻouʻou summit on the leeward side. The new infestation site presents several logistical challenges for response efforts. The remote location, steep slopes inaccessible by foot and highly variable weather, prevent crews from using a traditional hose-based spray system to deliver a non-toxic citric food additive mixed with water used to control the frogs.

DOFAW field staffers are planning to use drone technology to apply the citric treatment at these higher elevations. Aloha ʻĀina Drones, a Hilo-based operation specializing in agricultural and conservation drone applications, is contracted to do the work.

In Hawaiʻi, coqui reach densities much higher than in their native Puerto Rico. Their loud calls disturb residents and the invasive frogs have large impacts on local insect communities. Coqui are now widespread on Hawaiʻi Island and are targets of control efforts on Kauaʻi, Oʻahu and Maui.

To date, the frogs have not been detected at lower elevations on the leeward side of the Koʻolau Mountains. Kuliʻouʻou residents and hikers on the Kuliʻouʻou Ridge Trail and Kuliʻouʻou Valley Trail are encouraged to listen for frog calls. Pest reports can be submitted online at 643pest.org or by calling the 643-PEST telephone hotline. Staff from DOFAW and OISC will be present at the October 2, 2024 meeting of the Kuliʻouʻou Neighborhood Board to share information and answer questions about this project.

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RESOURCES

(All images/video courtesy: DLNR)

HD Video – Waimānalo Coqui Frog Eradication (May 16, 2022):

https://vimeo.com/710563069

Photographs – Coqui Frog Eradication Oʻahu (May 2022):

https://www.dropbox.com/scl/fo/0fcd8b4vp1ef9xppjpupn/APqEluEA1r1n21JX5Lg7XhY?rlkey=iqz60cfjk726dcvn0x4tn36dc&st=4mj0y3cp&dl=0

643pest.org Online pest reporting: https://www.643pest.org/

Hawaiʻi Invasive Species Council – Coqui Frogs: https://dlnr.hawaii.gov/hisc/coqui-frog