Federal Government Designates Critical Habitat for Threatened I’iwi


In late December, the US Fish and Wildlife Service announced plans to designate more than 275,000 acres as protected critical habitat for the I’iwi, Hawaii’s best-known endangered creeper.

The Center for Biological Diversity sued the agency in 2021 for failing to designate critical habitat that Hawaiian forest birds desperately need to survive. The announcement protects habitat on the islands of Kaua’i, Maui and Hawai’i.

“Protecting the places where the I’iwi call home will give these magnificent birds their best chance of survival,” said Maxx Phillips, Hawaii director and attorney for the Center. “This should not have required a lawsuit, but the Service did the right thing.” As our forests fall silent, federal authorities must do all they can to ensure these birds bounce back and stop sliding into extinction.

The ‘I’iwi are known for their iconic bright red plumage, black wings, and distinctive long, curved bills. They were once one of Hawaii’s most abundant native forest birds. The birds now live on only three islands, with Kaua’i’s population likely to disappear within 30 years.

Like many native Hawaiian forest birds, the ‘I’iwi have extremely low resistance to avian malaria, with an average mortality rate of 95%. The combination of low resistance and high mortality means that almost all I’iwi who come into contact with avian malaria die from it.

Since mosquitoes cannot live at higher altitudes due to cooler temperatures, the birds survived in higher altitude forests. But as global climate change accelerates, temperatures at higher elevations in Hawaii are increasing.

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The critical habitat designation recognizes these threats and indicates that it may be necessary to eliminate mosquito breeding sources. The Service also recognized the need to protect and restore native high elevation forests. Earlier this month, the Interior Department released a separate plan aimed at preventing imperiled Hawaiian birds from becoming extinct.


The U.S. Fish and Service listed the i’iwi as threatened in 2017, but it failed to designate its critical habitat. Species without designated critical habitat are half as likely to progress towards recovery as species with critical habitat. Without protection of its critical habitat, the ‘I’iwi will continue to lose what little disease-free forest habitat remains. Additionally, species with a timely recovery plan for two or more years are much more likely to improve than those without.

Besides the devastating damage caused by mosquitoes and climate change, the rapid death of ‘ōhi’a trees further threatens the survival of ‘I’iwi. The birds rely on ‘ōhi’a for nesting and feeding, surviving primarily on nectar from lehua flowers. Although originally limited to the island of Hawaii, the rapid death of the ‘ōhi’a spread to Kaua’i, Maui, and O’ahu. Since there is no effective way to contain the disease, the death of the ‘ōhi’a forest poses a significant risk to the continued survival of the ‘I’iwi.

Hawaiian forest birds are among the most endangered groups of birds in the world. Some 68% of Hawaii’s known endemic bird species have already become extinct due to 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 recently observed and are considered by scientists to be extinct. Introduced mosquitoes and the diseases they carry are the main causes of the loss of all these birds.

Thanks to the Center for Biological Diversity for providing us with this news.