About 20,000 male mosquitoes have been released into the upland forests of Kauaʻi in hopes of stopping the near extinction of at least four species of Native Hawaiian honeycreepers.
These mosquitoes are carrying bacteria that will drastically help reduce the mosquito population and prevent the biggest threat to critically endangered birds — mosquito-borne diseases.
Mosquito-borne diseases like avian malaria have led to a rapid decline in the population of Native Hawaiian honeycreepers. One species, the ‘akikiki, has declined to as few as five or six birds in the wild.
“I mean it’s just really sad to know that our forest birds are suffering so greatly from these mosquito-borne diseases,” said Dr. Cali Crampton, who leads the Kauaʻi Forest Bird Recovery Project.
“But after years of trying everything we can to save them from extinction, it’s a relief to know that we are on the cusp of releasing a tool that can reverse those declines," she said.
Crampton is one of a dozen researchers and technicians who began releasing mosquitoes into the forests of Kōkeʻe and the Alakaʻi Plateau last week. The Kauaʻi Forest Bird Recovery Project has been studying the impact of mosquitoes on native forest birds for more than a decade.
“This is called a mark release recapture study where we are releasing about 20,000 mosquitoes from this one release point, and then measuring how far they move throughout this area. So, we're looking at collecting data on how far they travel through the forest and how long they live,” said Bryn Webber, the mosquito research coordinator at KFBRP.
“So that's gonna be used for our landscape-level releases next year so we can inform how far, how many pods we need to release and how far those mosquitoes disperse throughout the landscape," Webber said.
The 20,000 culex male mosquitoes were first given a strain of the bacteria Wolbachia, which will prevent female reproduction. Female mosquitoes that carry avian malaria have moved to higher elevations due to a warmer climate.
“We’re only releasing males. They don’t bite and when they breed with the females, the eggs won’t hatch. So that will cause a crash in the mosquito population up here,” said Mele Khalsa, natural resources manager on Kauaʻi with The Nature Conservancy.
“We’re just doing a small scale, pilot release … in order to see how the mosquitos move through the forest out here. We have a whole grid of traps out in order to document how they’re moving and how they’re dispersing,” Khalsa asked.
The group will monitor 60 traps set up in a 300-meter radius from the release point every day for the next ten days. The data collected will help them plan for larger-scale operations.
