They drop mosquitoes from helicopters to save songbirds

There are kiwikiu, akiapolaau and akikiki.

In Hawaii, these songbirds with such beautiful names face a threat: mosquitoes. They spread a deadly disease, avian malaria.

To save them from extinction, scientists decided to treat one disease with another. How? By dropping containers filled with live male mosquitoes from helicopters, reports the American website Vox .

“For over a year now, environmental groups have been dropping biodegradable mosquito-filled cones from helicopters on the islands of Maui and Kauai into the habitats of endangered birds. Drone drops have also recently been used,” the American website reports.

“These open boxes fall to the ground, and the insects then escape into the forest.”

“The mosquito [introduced to Hawaii

in the 18th ^century ]

proliferated very quickly in the archipelago, before becoming the vector of avian malaria, a parasitic disease that this insect transmits through its

stings.”

The American news site Vox

But the mosquitoes released today are not like the others. For one thing, they are only male mosquitoes, so they don't bite.

Then, the insects were bred in laboratories and carried a strain of bacteria that hinders fertility.

“When they mate with local females, their eggs fail to hatch – this little biological magic trick is called the 'incompatible insect technique' (IIT).”

“The TII method creates an invisible barrier to prevent malaria-carrying mosquitoes from moving up into the forests where the species live

not affected.”

Chris Farmer, director of the Hawaii program at the American Bird Conservancy, told the American website Vox

Because potentially deadly avian malaria has devastated bird populations in Hawaiian forests, particularly one family of passerines: the Fringillidae.

“There were once more than fifty species of these brilliantly colored songbirds in Hawaii. Today, only seventeen remain. I saw it with my own eyes, or rather with my own ears: silence has fallen over the forests,” sighs the Vox journalist.

“Dropping mosquitoes from drones and helicopters sounds crazy,” concedes Marm Kilpatrick, an avian malaria specialist at the University of California, Santa Cruz.

But for him, “it’s the best solution available to save Hawaii’s birds.”

Because until now, the species that have escaped extinction are those that lived at high altitudes: their cooler habitat protected them from mosquitoes.

But climate change is warming the islands, so insects are penetrating the last avian strongholds.

Time is running out. Since late 2023, the organizations known as Birds, Not Mosquitoes have released more than 40 million male mosquitoes on Maui and Kauai.

“These introductions were almost all done from helicopters, which allows the insects to be sent into these isolated forest areas where the birds live.”

This mosquito release operation is not the first of its kind.

After being developed in Melbourne, Australia, it has been deployed in twelve countries (including Brazil and Singapore) to combat the spread of dengue fever, chikungunya and the Zika virus.

“The idea is to continue regularly, and for an indefinite period, to release mosquitoes in the forests where the most critically endangered birds live, including the kiwikiu (Maui's cuckoo bird), the akohekohe (the crested palmetto) and the akekee (Kauai's loxopsis),” Vox explains.

Chris Farmer is convinced: “This is our last chance to save what remains of our songbirds.” —