More than 30 years after a federal judge ordered the state to fix a broken fence on the upper slopes of Mauna Kea on the Big Island in order to protect endangered birds, officials will finally spend about $1 million to patch the holes.

The purpose of the fence? To protect thousands of acres of critical habitat for the endangered palila birds. The fence will also eventually block sheep from the lower slopes from entering the area.

But now, there are as many as 2,000 sheep inside the birds’ area. So the fence will also trap the sheep, allowing state officials to more easily kill or remove them.

The Sierra Club and National Audobon Society sued the Hawaii Department of Land and Natural Resources in the 1970s, arguing that the state was breaking the law by not protecting the birds that were listed as an endangered species in 1967. A federal judge agreed and ordered the state to repair a 55-mile fence around the bird habitat and get rid of the sheep and any roaming goats.

The state has fought the ruling on and off for three decades, unsuccessfully. The court issued additional orders in 1987 and 1998 telling the state to fix the fence. In 2009, environmental groups sued the state again, but backed off when the state said it was going to comply, according to Paul Achitoff, an attorney for Earthjustice, a local environmental law firm that represented the groups.

The palila, a small bird with a yellow head and breast and grey plumage doesn’t exist anywhere else in the world except along a small area of Mauna Kea.

DLNR estimates that there are up to 1,500 birds left. State expenditures on prior sheep eradication methods during the past 15 years, as well as $1 million in anticipated fence repairs and a maintenance cost of $350,000, will bring the cost per bird to roughly $1,400.

The fence will enclose about 60,000 acres of land — an area about two-thirds the size of the island of Lanai. While the birds only inhabit about one-sixth of the area, the entire parcel has been designated by the federal government as their critical habitat.

Once the fence is up, any sheep inside will be killed by sharpshooters in helicopters and hunters, under the state’s plan.

It’s possible that the sheep can be herded by helicopter into an adjacent parcel of land if DLNR can find land to lease. But a plot has yet to be secured, said Scott Fretz, the wildlife program manager for the Hawaii Department of Land and Natural Resources

“We don’t know that we can move the sheep anywhere,” said Fretz. “If we have a willing landowner then we certainly will work with them. But so far, we don’t.”

Unfortunately for the sheep, which are a cross between mouflon and what are referred to as feral sheep, the palila are picky eaters.

They feast almost exclusively on the seeds from mamane trees, the same trees that are also a favorite of the sheep, which eat their shoots and bark.

Scientists say it’s destroying the forest and the palila birds’ habitat. So the sheep have to go.

But there could be a problem. The grass-eating sheep help prevent wildfires, which are a greater threat to the palila, according to hunters.

“It’s like a matchbox,” said Colin Onaka, president of Hui Kuahiwi, a group of local hunters, who also has a business leading hunting expeditions. “If there’s a lack of animals there’s nothing eating the invasive plants and plant species. What we are afraid of is that if the place catches fire we are going to lose everything. We are going to lose birds and lose native plants.”

Sheep are often used to control wildfires and studies have shown them to be effective.

But Fretz said there’s no evidence that the sheep, at their current numbers of 1,000 to 2,000, were preventing fires. And he said the issue was irrelevant.

“It’s kind of beside the point because if we have that many sheep, we’re not going to recover the palila,” he said. “We have to get the sheep off the mountain.”

Hunters Up in Arms

The plan to eradicate the sheep is enflaming long-simmering tensions between DLNR and local hunters who oppose more fencing of public lands and object to aerial shootings. They say it’s unethical and wasteful because animals are just left to rot.

DLNR officials conduct the aerial operations several times a year. Since 1997, more than 5,000 sheep have been shot from helicopters in the palila’s critical habitat area, according to Fretz, at a cost of $25,000 to $50,000 a year.

He said that officials are able to recover about 75 percent of the sheep and the meat is given away to the public.

Controlling the sheep is critical to managing the habitat for the palila as well as preserving biodiversity and protecting critical watershed areas in other regions, according to DLNR.

But the aerial shootings have become a contentions issue on the Big Island. Last week Mayor Billy Kenoi signed a bill banning them, an action that’s mainly seen as symbolic since the state is not bound by county law.

Still, it was cheered by local hunters.

Onaka said that aerial shooting was “very inhumane and unethical.” He said that the sheep were so used to the helicopters chasing them that they had figured out how to run under the helicopters to avoid being shot.

“They chase (the sheep) until they just die from exhaustion,” he said. “Or they chase them until they run into fences and die — they break their necks or get hung up in the fences.”

Fretz said that he was not aware of any such cases and that this would contradict DLNR policies.

“With regard to driving of animals, that is only done when it can be done humanely without risking exhaustion to the animals,” he wrote by email.

Achitoff, the Earthjustice attorney, said that the hunters had been fighting the removal of the sheep for years. He dismissed concerns about the way the operation is conducted as well as any worries over increased risk of fire.

“The hunters like to be able to drive up in a pick-up truck and shoot the sheep through their window without having to work,” said Achitoff. “They get incensed if anyone makes their job more difficult.”

Onaka said that hunters have to walk several miles to hunt the sheep.

“If he can come within shooting distance with an animal up on Mauna Kea, I’ll give him $1,000,” he said. “They’re so sparce and so spooked.”

Fretz said that the aerial shooting would increase after the fence was closed off, but hunters would also be encouraged to kill the sheep. The fence is expected to be finished in about a year.

“When the fence is completed, the staff shooting will be effective,” he said. “Right now, the sheep are constantly coming in from outside. Once we have the fence completed the aerial shooting will finally be effective and finally get the numbers down.”