Drones will control frogs found at higher elevations in the Ko?olau Mountains 

HONOLULU - Invasive coqui frogs have been found at higher elevations than previous infestations on O?ahu. 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 Kuli?ou?ou Ridge Trail on the leeward side of the mountains. Surveys were subsequently performed by the DLNR Division of Forestry and Wildlife (DOFAW), and the O?ahu Invasive Species Committee (OISC).

It is estimated that 13 acres of forest are infested below the Kuli?ou?ou 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 ??ina Drones, a Hilo-based operation specializing in agricultural and conservation drone applications, is contracted to do the work.

In Hawai?i, 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 Hawai?i Island and are targets of control efforts on Kaua?i, O?ahu and Maui.

To date, the frogs have not been detected at lower elevations on the leeward side of the Ko?olau Mountains. Kuli?ou?ou residents and hikers on the Kuli?ou?ou Ridge Trail and Kuli?ou?ou 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 Kuli?ou?ou Neighborhood Board to share information and answer questions about this project.