With its bright red plumage and down-curved bill, the iiwi is a living symbol of Hawaii that for so long seemed to resist the tide of extinction that overcame so many of its native Hawaiian cousins.

But any perception of invincibility is no longer valid.

The iiwi, or scarlet honeycreeper, has finally achieved the status of threatened species under the U.S. Endangered Species Act, a recognition that the bird is in need of protection if it is to survive.

The U.S. Fish and Wildlife Service announced the designation Tuesday, saying the listing is warranted based on its review of scientific research and public comments.

“It means this is a species in trouble,” said Holly Richards, public affairs officer with the Fish and Wildlife Service’s Pacific Islands Office.

The next step is the development of a recovery plan with input from federal and state agencies, conservation groups and the public, Richards said.

The designation was one of three announced Tuesday. The two other species receiving protection are Arizona’s Sonoyta mud turtle and a bird from the Southeast called the pearl darter.

Tuesday’s action is a result of two 2011 settlement agreements with the Center for Biological Diversity and WildEarth Guardians that has led to the designation of 188 species as either threatened or endangered over the past six years. Another 11 species could receive protections by the end of the year.

“We’re thrilled these three endangered species are finally getting the protections they so desperately need to survive,” Noah Greenwald, the center’s endangered species director, said in a news release. “We worried that Trump administration political appointees would block the Fish and Wildlife Service from protecting any species, but for at least these three, this is a good day.”

The iiwi was once plentiful throughout the islands, from the mountains to the sea. But now 90 percent of the population is restricted to a narrow region of forest on East Maui and on the windward side of Hawaii island above 4,265 feet in elevation.

At those heights the iiwi and other forest birds were able to avoid the avian malaria infection spread by invasive mosquitoes that live in the warmth of the lower elevations. But with a warming climate, mosquitoes have been migrating to higher ground, and avian malaria is known to kill some 95 percent of infected iiwi.

Making matters worse is that the ohia forest, the habitat upon which the iiwi depends for survival, is now threatened by the scourge of rapid ohia death, an invasive tree pathogen that is on the move on the Big Island.

Iiwi have just about vanished from Lanai, Oahu, Molokai and West Maui, while the birds have experienced a 92 percent decline on Kauai over the past 25 years and a 34 percent decline on the Valley Isle, according to the Center for Biological Diversity, which petitioned for protection for the iiwi in 2010.

The IUCN Red List describes the species as “vulnerable,” the designation just below “endangered,” due to its ongoing population decline.

“Working with the state, our conservation partners and the public will be crucial as we work to recover the iiwi,” Mary Abrams, project leader with the Pacific Islands Fish and Wildlife Office, said in a news release. “The service is committed to building on our record of collaborative conservation to protect Hawaii’s native species.”

The final listing rule will be published in the Federal Register and become effective today.