Saving Maui's Forest Birds
Hawaii’s native birds are among the most imperiled on earth. Habitat loss, invasive species, disease, and climate change have caused the extinction of dozens of native species. Now, an ambitious plan to eradicate mosquitos using “mosquito birth control” could be the native birds’ saving grace. But with honeycreepers like the Kiwikiu (Maui Parrotbill) projected to go extinct in the next decade, can conservationists control mosquitos in time?
The Bird Extinction Capital of the World
Approximately 5.5 million years ago, a species of Eurasian rosefinch flew or was blown to the Hawaiian Islands. Finding a diversity of unfilled niches, that one species radiated into 54 species of Hawaiian Honeycreeper. Like Darwin’s finches of the Galapagos, each honeycreeper evolved a specialized bill to suit its needs. There are nectar feeders with long, curved proboscises, insect hunters with small, sharp warbler bills, seed eaters with the thick bills of grosbeaks, and even pseudowoodpeckers which probe and scrape loose bark in search of insect larvae.
Once humans reached the islands everything changed. Habitat loss coupled with invasive species and diseases caused the extinction of 36 unique honeycreeper species. Only 18 species of honeycreeper remain.
Most insidious of all, the accidental introduction of mosquitos to Hawaii led to outbreaks of avian malaria in the naïve bird populations. Today, Hawaii’s native forest birds are only found at elevations above 4,500 feet where disease-carrying mosquitos cannot survive.
Mosquito Birth Control
As climate change warms the slopes of Haleakalā, the 10,000-foot shield volcano in East Maui, mosquitos are beginning to penetrate Maui’s last refuges.
The Maui Forest Bird Recovery Project traps mosquitoes to track malaria presence as the insects move up slope. Mosquito trapping is just the beginning of an ambitious mosquito eradication plan. Using a quirk of insect biology, researchers have discovered a possible mosquito birth control.
Mosquitos with different strains of Wolbachia, a naturally occurring bacteria, cannot produce viable offspring. In the coming years, researchers plan to release millions of male mosquitos (which do not bite) with a strain of Wolbachia incompatible with female mosquitos, thus leading to a collapse in the mosquito population.