Settlement talks in a dispute over bright lights at an oceanfront Maui resort and the endangered seabirds they affect continued Thursday.

But the negotiations have yet to produce an agreement. With fledging season coming up next month, the case against Grand Wailea is headed for trial unless a breakthrough emerges.

Environmental activists who filed the suit say that the resort is violating the Endangered Species Act by failing to take adequate measures to protect the birds. The resort has denied the allegation and asked a judge to dismiss the lawsuit.

David Henkin, a senior attorney for Earthjustice, said he’s “guardedly optimistic” about the chances for a settlement. But until it’s in hand, Henkin is preparing a motion to ask a federal judge for a preliminary injunction, forcing the hotel to take steps to protect the birds from further harm. Henkins’ clients are the Conservation Council for Hawaii and the Center for Biological Diversity.

A resort spokesman expressed some optimism that the two sides will reach an agreement.

“While we do not comment on active litigation, we remain hopeful that this matter will be settled. Grand Wailea is actively implementing protective measures ahead of the upcoming seabird fledgling season,” Dylan Beesley, senior vice president, Bennet Group Strategic Communications, said in an email.

Asked what measures the hotel is taking, Beesley did not respond.

Henkin said the resort has adjusted the lighting somewhat to help prevent the petrels from grounding but, in his view, the steps it has taken are inadequate.

During fledgling season, which runs from late September to early December, Hawaiian petrels heading to sea for the first time can be attracted by the resorts’ artificial lights. The birds get mixed up thinking the lights are the moon’s reflection on the ocean.

The birds are known to circle in the artificial glow until they fall to the ground, disoriented and exhausted. Once grounded, they can have trouble getting up and flying away. Or they die from attacks by mongoose, rats, feral cats or other predators.

According to Earthjustice’s lawsuit, filed earlier this year in federal court in Honolulu, at least 15 petrels grounded at the Grand Wailea due to light attraction between January 2008 and December 2021. One of them died in October, according to the complaint.

Others are believed to have died but they were never found, Henkin said.

“There is no systematic search for downed birds. They come down at night. The birds fly at night and when they come to the ground, they tend to hide quickly. So the fact that they found one bird likely means there were likely many other birds that were not discovered,” he said.

The issue of artificial light and endangered seabirds isn’t new to Hawaii. Earthjustice sued the former St. Regis Princeville Resort in 2010 over lighting that threatened Newell’s shearwaters and Hawaiian petrels. The resort subsequently took bird-friendly steps like keeping fountain lights off during the fledgling season and coming up with a monitoring system to search and respond to downed birds.

“We’re urging the Grand Wailea to follow that model,” Henkin said.

The two sides held settlement talks on July 14. After that meeting, attorneys for Grand Wailea asked the judge to seal a transcript of the proceedings, a motion that was granted, according to court documents.

Beesley didn’t respond when asked why resort attorneys wanted the details kept secret.

Another round of talks is scheduled for Monday. If no settlement is reached, a trial is set to begin in April 2023.