Eleutherodactylus coqui
Coqui shown next to human hand for size reference.
Coqui Frogs were accidentally introduced to the Big Island in the late 1980’s on imported nursery plants. Beloved in their native Puerto Rico, coqui in Hawaii lack the natural predators that keep their population in balance, and their numbers quickly exceeded population densities of their home range. On the Big Island, coquis are recorded to reach densities as high as 2000 frogs per acre, more than twice the number found in similar areas in the Caribbean.
Hawaii evolved with no native terrestrial amphibians, and the natural ecosystem here is not adapted for their presence. Coqui are voracious eaters and although they will consume any insect they find, most of their forage time is spent in leaf litter looking for their invertebrate prey, which may be introduced or native. As many of our native invertebrates are already threatened by reduced habitat, coqui pose a troubling threat to our native ecosystems. Studies have shown they eat most crawling insects, not mosquitoes, as once had been hopefully suggested. Many homeowners throughout Puna have reported that high density infestations of little fire ants will reduce populations of coqui frogs, although these residents also indicated that this benefit was not enough to tolerate fire ants.
The distinctive “KO-kee” call that gives the frog its name can reach 100 decibels, louder than many power tools and lawn equipment, and can can be very disruptive for residents in infested areas. The males will call from dusk to dawn to ward off competitors and attract a mate. In the morning, the frogs retreat to the ground and look for moist, shady areas to spend the day. Homeowners in highly infested areas have reported that in recent years, coqui will even call on overcast days or from heavily shaded areas.
Egg mass of coqui frog.
Coqui have completely invaded most of East Hawaii from Glenwood to Kalapana and throughout North Hilo, with dozens of smaller populations sprinkled throughout the rest of the island. They are tree frogs, but are capable hitchhikers who have evolved to move with human belongings as we travel from place to place. Although potted plants are the most common route of spread for many invasive plants, coqui are known to travel in garbage cans, vehicles, camping equipment, and whatever they can cling to! Reducing habitat, enacting vigilant biosecurity, and working with your neighbors is the best way to prevent or control a coqui infestation in your neighborhood.
Resources to help with control of coqui:
View this short video from the North Kohala Community Resource Center to learn some techniques for controlling coqui:
Kohala Coqui Coalition from Derrick Owens on Vimeo.
Download our trifold brochure for handy tips on controlling coqui on your property: Coqui Brochure (Final)
If you and your neighborhood would like to find a large capacity tow-sprayer to apply citric acid over large areas, please contact us at biisc@hawaii.edu or at (808)933-3340 and we will connect you with a sprayer contact in your area.
On the West side of Hawaii Island, there are multiple independent businesses that can be contracted to help with coqui control.
