In a groundbreaking effort to conserve the critically endangered Hawaiian honeycreepers, scientists have developed a novel approach using mosquito "birth control" technology. The ʻākohekohe, also known as the crested honeycreeper, is a unique species endemic to Maui, Hawaii, but faces severe threats from mosquito-borne diseases, particularly avian malaria. This species is on the brink of extinction, with fewer than 2,000 individuals remaining.

To combat this crisis, a multidisciplinary team has devised a strategy that involves the use of sterile male mosquitoes. These mosquitoes are produced by infecting them with Wolbachia, a naturally occurring bacterium that disrupts the reproductive capabilities of male mosquitoes when introduced into their populations, specifically targeting the invasive Aedes aegypti species.

When these sterile males mate with wild female mosquitoes, the eggs produced cannot be fertilized, leading to a significant decrease in mosquito populations. This innovative method, known as the Incompatible Insect Technique (IIT), has shown promise in various regions across the globe for controlling diseases such as dengue and malaria.

Emma Shelly, a scientific outreach specialist and Outreach Manager with Birds, Not Mosquitoes, explained that the sterile mosquitoes used in Hawaii are descendants of local populations, and multiple generations have been bred to produce the required quantity for the project.

One of the major advantages of this technique is that male mosquitoes do not bite or transmit diseases—they solely feed on plant juices and nectar. Furthermore, because the introduced mosquitoes are not genetically modified and Wolbachia is found in over 60% of wild insect species, this approach is considered safe for the ecosystem.

To effectively deliver these sterile males into the wild, the conservation team has employed drones. Unlike traditional aerial methods that may pose risks to human operators, drones can safely deploy the mosquito pods across the rugged and mountainous terrain of Hawaii's forests.

Adam Knox, a drone pilot and Aerial Deployment of Mosquitoes Project Manager for the American Bird Conservancy, noted that the drones used for this project are specially equipped to manage the delicate task of mosquito delivery. These drones are capable of carrying biodegradable pods, each containing about 1,000 sterile male mosquitoes, to areas where the invasive mosquito populations are most problematic.

The pods are made of sterilized biodegradable materials, ensuring that they break down naturally after release. Each drone can carry up to 23 pods at a time, facilitating the efficient distribution of mosquitoes across thousands of acres.

This initiative marks the first known use of drone technology to deploy mosquito pods, illustrating how technological advancements can be harnessed for conservation efforts. The first successful drone deployments occurred in April 2025, following rigorous testing to ensure that the drones could operate safely in Hawaii's challenging conditions, including strong winds and varying elevations.

Originally, mosquito deliveries began in 2023 using helicopters, but the switch to drones offers numerous advantages, including improved safety for personnel and greater flexibility in deployment timing, especially in areas with unpredictable weather.

Notably, the IIT approach complements other conservation strategies aimed at protecting Hawaii's endangered bird species, such as habitat restoration and controlling invasive species and predators. The San Diego Zoo Wildlife Alliance operates facilities in Hawaii where small populations of endangered birds are bred in captivity, awaiting the day when it becomes safe to return them to the wild.

Hawaii's native bird species, particularly the honeycreepers, have faced immense challenges due to the introduction of invasive species like Aedes aegypti, which was brought to the islands in the 19th century. The range of these mosquitoes has expanded due to climate change, putting all native bird species at risk.

Chris Farmer, the American Bird Conservancy's Hawaii Program Director, emphasized that without significant reductions in invasive mosquito populations, several native bird species are at a high risk of extinction. Sadly, at least 33 species of honeycreepers have already been lost to avian malaria, and many of the remaining species, such as the Kiwikiu and ʻĀkohekohe, are critically endangered.

The IIT mosquito delivery project represents a glimmer of hope in the effort to save Hawaii's unique avian heritage. As scientists work tirelessly to implement this innovative approach, they remain committed to ensuring that the islands' extraordinary native birds do not vanish forever.

For those interested in learning more about these efforts, the American Bird Conservancy has produced a moving video, titled "Vanishing Voices," which showcases the organization's collaboration with Birds, Not Mosquitoes and emphasizes the urgent need to prevent the extinction of Hawaii's iconic native bird species.