In late December, the U.S. Fish and Wildlife Service announced it plans to designate more than 275,000 acres as protected critical habitat for the threatened ‘I‘iwi, the best known of Hawai‘i’s imperiled honeycreepers.
The Center for Biological Diversity sued the agency in 2021 for failing to designate critical habitat that the Hawaiian forest birds desperately need to survive. The announcement protects habitat on the islands of Kaua‘i, Maui, and Hawai‘i.
“Protecting the places the ‘I‘iwi calls home will give these beautiful birds their best chance at survival,” said Maxx Phillips, Hawai‘i director and staff attorney at the Center. “It shouldn’t have taken a lawsuit, but the Service made the right call. As our forests fall quiet, federal officials must do everything possible to ensure these birds bounce back and stop sliding toward extinction.”
‘I‘iwi are known for their iconic bright red plumage, black wings, and distinctive long, curved bill. They were was once one of the most abundant native forest birds across Hawai‘i. The birds now live on only three islands, with the population on Kaua‘i likely to go extinct within 30 years.
Like many native Hawaiian forest birds, ‘I‘iwi have an extremely low resistance to avian malaria, with an average 95% mortality rate. The combination of low resistance and high mortality means that nearly every ‘I‘iwi that comes into contact with avian malaria dies from the disease.
Since mosquitoes can’t live at higher elevations because of cooler temperatures, the birds have survived in higher-elevation forests. But as global climate change accelerates, temperatures at higher elevations in Hawai‘i are increasing.
The critical habitat designation acknowledged these threats and says removing mosquito breeding sources may be needed. The Service also acknowledged the need to protect and restore high-elevation native forests. Earlier this month, the Department of the Interior released a separate plan to prevent the extinction of imperiled Hawaiian birds.
The U.S. Fish and Service listed the ‘I‘iwi as threatened in 2017, but it failed to designate critical habitat. Species without designated critical habitat are half as likely to move toward recovery as species with critical habitat. Without protections for its critical habitat, ‘I‘iwi will continue to lose what little disease-free forest habitat remains. Additionally, species with timely recovery plans for two or more years are far more likely to improve than those without.
Alongside the devastating harm from mosquitoes and climate change, rapid death of ‘ōhi‘a trees are further threatening the ‘I‘iwi’s survival. The birds depend on ‘ōhi‘a for nesting and foraging, surviving primarily on nectar from lehua blossoms. Though originally limited to the island of Hawai‘i, rapid ‘ōhi‘a death has spread to Kaua‘i, Maui, and O‘ahu. Since there is no effective means of containing the disease, ‘ōhi‘a forest death poses a significant risk to the continued survival of the ‘I‘iwi.
Hawaiian forest birds are among the most imperiled groups of birds in the world. Some 68% of Hawai‘i’s known endemic bird species have already gone extinct because of habitat loss, disease, and invasive predators. Of the remaining 37 surviving endemic species, 33 are currently listed under the Endangered Species Act, although nine of these have not been observed recently and are thought by scientists to be extinct. Introduced mosquitoes and the diseases they carry are primary causes of the loss of all these birds.
Thanks to the Center for Biological Diversity for providing this news.