On a rugged hillside south of Antelope, wildlife biologist J.D. McComas spent two nights last week waiting to shoot a feral pig that was destroying nearby farmland.

Each night, McComas drank coffee to stay awake as he used night-vision equipment to spot the pig in the darkness. But it never showed.

Hunting the last of the feral swine in Oregon takes patience.

McComas, a Madras-based wildlife biologist with the United States Department of Agriculture Wildlife Services, was assigned to lead ­Oregon’s effort to eradicate the invasive feral swine species in January 2017.

About a decade ago, the feral swine population in the state grew to more than 3,000. The pigs are one of the most dangerous invasive species in Oregon and cause damage to agricultural crops and fish and wildlife habitat.

Through aerial hunting from helicopters and corral trapping, the population has been reduced to less than 200. The remaining swine are roaming in the vast wilderness of Central Oregon, from Madras to Shaniko, and in the open terrain along the California border.

Finding the stragglers takes long nights of hunting and corral trapping in the remote terrain, McComas said.

“For the most part, they inhabit some of the roughest country Central Oregon has to offer,” he said. “That High Desert country and canyons that have seen nothing but cattle for years. We had to cover a lot of ground just to find them.”

State officials started to address the feral swine problem nearly two decades ago. In 2001, a law was passed to reclassify the pigs from livestock to predatory animals, allowing them to be hunted without regulation.

In 2009, the Oregon Legislature passed a law requiring landowners to notify the Oregon Department of Fish and Wildlife if they see feral swine on their land. The law also made it illegal to sell swine hunts because those operations bring in pigs and if any escape, the population problem will worsen.

Feral swine spread in Oregon mostly through people bringing in exotic European and Russian boars for private hunts.

Some of the boars would escape and breed with escaped domestic pigs, said Rick Boatner, ODFW’s invasive species wildlife integrity coordinator.

“People were bringing in Russian boars, and they cross bred with domestic swine,” Boatner said. “Fairly often, we found hybrids.”

Feral swine can start breeding as early as 6 months old, and produce at least two litters per year with up to 12 in a litter.

They can grow to nearly 300 pounds, and as omnivores they eat almost anything in their paths. They can eat small birds and young deer but also dig up roots in farmland and protected riparian areas.

Most of the damage is done during the night because they are nocturnal animals.

“They can go in and damage acres of pasture land,” Boatner said. “Then you have weed patches instead of grass for your cattle.”

Besides the environmental damage, feral pigs also carry up to 40 separate diseases that are dangerous to humans and livestock.

Boatner said the Oregon population is relatively disease free, although one was found with swine flu, a respiratory disease in pigs that can spread to humans.

“Feral swine are a walking disease factory,” Boatner said.

About five years ago, U.S. Congress recognized the threat of feral pigs in each state and designated nearly $20 million to eradication efforts, according to David ­Williams, director of USDA wildlife services in Oregon.

The U.S. agriculture department was tasked with leading land managers and private landowners in each state to help eliminate feral swine.

Oregon initially received $165,000 in federal money per year, which helped rent a helicopter for aerial hunts.

About three or four times per year, Oregon wildlife officials would ride in a helicopter, flying at a low altitude to find large groups of feral pigs. As the helicopter pilot hovered above them, another person would use a 12-gauge shotgun to shoot the swine.

One flight could take down more than 100 swine.

Recovering the carcasses can be time consuming, so they are usually left behind on terrain that is often too rugged to safely land a helicopter, Williams said. And if landowners want to keep a carcass, they have to have it inspected for diseases before it can be prepared.

Overall, the use of helicopters in Central Oregon eliminated about 1,200 feral swine.

The aerial hunting was the most effective way to reduce the population, but it hasn’t been as necessary in recent years since the remaining pigs are hard to find from the sky, according to wildlife officials.

Helicopter flights were only done twice last year and once this year. Each flight only spotted about four swine.

Wildlife officials have entered the hardest part of the eradication effort — tracking and killing the few remaining pigs.

To assist the final push in Oregon, the annual federal funding was bumped up $245,000 last year, and McComas was brought in as the lead biologist.

“Now, we have our lead biologist and we have a helicopter we can use and from time to time we will also assign some of our staff to work with landowners to run a lot of corral traps and monitor trail cameras to try to get to the last hold-outs of feral swine,” Williams said.

Because of how quickly feral swine breed and how people are still bringing them in for illegal private hunts, wildlife officials worry the population could grow again.

McComas and his colleagues are working hard to eliminate the swine and monitor any new sightings.

If they start to back off now, they could find themselves back to where they were a decade ago, when thousands of swine damaged the landscape, McComas said.

“We are doing everything in our power to keep the foot on the pedal,” he said. “Eventually, we will catch up with them all.”

— Reporter: 541-617-7820, kspurr@bendbulletin.com