Earthjustice has filed suit against Maui County over streetlights that disorient endangered and threatened Hawaiian seabirds.

Earthjustice, which is representing the Conservation Council for Hawaii and the American Bird Conservancy, also named Hawaiian Electric in the suit in U.S. District Court, but recently reached a settlement with the utility over steps it would take to protect seabirds from collisions with its power lines on Maui.

The groups are concerned about three seabirds — the endangered Hawaiian petrel, or uau; the endangered band-rumped storm petrel, or akeake; and the threatened Newell’s shearwater, or ao.

Conservationists say the birds, which are guided by the moon and stars at night to navigate their way from nest to sea, are disoriented by the bright, artificial lights emanating from county streetlights.

This causes them to circle them until they fall, exhausted, leaving them vulnerable to predators, dehydration, or getting run over by cars.

“These birds are unique to Hawaii and we have already lost far too many of them,” said Jonee Peters, executive director of Conservation Council for Hawaii, in a news release. “There are proven solutions for reducing light attraction, like what Hawaii County has done to reduce the blue-light content of its streetlights on the Big Island. Maui County should follow suit.”

While Hawaiian Electric owns and operates the streetlights, Maui County dictates the parameters for streetlight operation on its roads, Earthjustice said.

Both the power lines and streetlights need to be addressed to protect the birds, the groups said.

Earthjustice said under the Endangered Species Act, both Hawaiian Electric and Maui County are liable for harm to the seabirds and must secure required permits, which involves coming up with habitat conservation plans.

Hawaiian Electric agreed to take certain measures — such as the installation of diverters on some of its power lines — while working to secure federal and state permits.

Maui County said it was unable to comment on pending litigation.

Brad Keitt, American Bird Conservancy’s Oceans and Islands director said today’s populations of both the uau and ao are only a small fraction of their historical numbers, with threats like Maui County’s streetlights continuing to drive those declines.

Known populations of endangered uau have dwindled to an estimated 12,000 to 16,000 individuals remaining in the wild; the Hawaiian population of endangered akeake remains at about 240 breeding pairs; and the estimated number of ao is at 10,000.

Maui County is home to some of the largest remaining colonies of Hawaiian petrels who nest near the summit of Haleakala on Maui and at Lanaihale on Lanai.

Hawaiian Electric has agreed to expedite its long-term project to lower power lines atop Haleakala. But the bright streetlights still pose a threat to the birds, particularly fledglings, as they make their way from their nests to sea.

“These streetlights are particularly dangerous for fledglings just starting to learn to navigate by moon and starlight, but adult birds can also suffer from fallout,” he said in a statement. “To help stop further populations declines, the County must abide by the Endangered Species Act and work with Hawaiian Electric to implement measures that prevent these unnecessary injuries and deaths.”

Keitt said there are a number of different solutions, such as the shielding of lights, reduction of lights when unnecessary, and use of certain wavelengths of light that make them less attractive to seabirds.

There has been precedence of how this can be done in the isles. The Kauai Seabird Habitat Conservation Plan of 2020, for instance, outlines detailed actions and strategies to lessen the impacts of artificial lights.

Conservation groups reached an agreement with the Grand Wailea Resort on Maui over the summer after filing a similar suit over artificial lights.

“All are options that need to be evaluated,” Keitt said. “We look forward to working with the county to lay out how those different options would be implemented.”