In June, dozens of biodegradable pods fell from the sky over the forests of Hawaii. Each one, delivered by drone, contained about 1,000 mosquitoes.

These weren’t just any mosquitoes — they were non-biting, lab-reared male mosquitoes carrying a common bacterium that results in eggs that don’t hatch when the males mate with wild females. The hope is that they will help to control the archipelago’s invasive mosquito population, which is decimating native bird populations, such as rare Hawaiian honeycreepers.

The birds, which are key pollinators and seed dispersers and also play a central role in Hawaiian culture, are in dire straits. There were once more than 50 known species of honeycreepers in Hawaii, but today there are only 17 left, most of which are endangered.

Last year, the ‘akikiki, a small gray bird, went functionally extinct in the wild, and less than 100 of the yellow-green ʻakekeʻe are estimated to remain.

Development and deforestation have had an impact, but according to Dr. Chris Farmer, Hawaii program director for the American Bird Conservancy (ABC), the “existential threat” is avian malaria, which is spread by mosquitoes.