The Center for Biological Diversity is suing the federal government amid the nonprofit group’s efforts to protect Hawaii’s iiwi, one of 17 forest bird species native to the islands that’s facing extinction.

The lawsuit, filed Wednesday in U.S. District Court, aims to compel the U.S. Fish and Wildlife Service to designate a critical habitat area for the iconic honeycreeper, known for its bright-red plumage, and to develop a recovery plan for its long-term survival.

The federal agency was required to do that when it listed the iiwi as “threatened” under the Endangered Species Act in 2017, the suit contends.

The main culprits in their demise are invasive, disease-carrying mosquitos introduced to Hawaii. Avian malaria has decimated Hawaii’s honeycreepers and other forest bird populations.

The iiwi and similar species have gradually sought refuge at higher, cooler elevations where the mosquitos can’t reach them. But researchers say that climate change is warming those habitats and allowing the mosquitos to reach the birds.

The center’s filing also points to the gradual demise of Hawaii’s native Ohia trees. Iiwi survive primarily on the nectar of the lehua blossoms of those trees. However, at least one million Ohia have perished in recent years, mostly on Hawaii island, due to the spread of Rapid Ohia Death.

Despite those perilous circumstances, the iiwi will have a much better shot at survival if they’re given critical habitat in these upper forest reaches, and that they’re protected “to the fullest extent of the law,” said Maxx Phillips, the Center’s Hawaii director and staff attorney.

That habitat could be maintained with fencing and planting of the trees that the iiwi need, she said. The Center had filed its intent to sue in October if no action was taken.

A potential long term plan to save Hawaii’s forest birds involves sterilizing the mosquitos that have overcome the islands. However, the birds will need federal protections to survive in the near-term, Phillips said.

“The saddest thing for me is hearing these forests go silent,” added Phillips, who grew up on Hawaii Island. The species makes a distinctive, crackling sound, she said. “They’re chatty birds.”