Feral pigs

Nick Gevock, right, of the Montana Wildlife Federation, speaks as part of a panel at a conference on the threat of feral pigs in Montana at the Northern Hotel on Friday, November 15, 2019.

Spotting a feral pig can be tough. 

While photographs from 2018 showed that feral swine that have recently exploded in population in Canada are only five miles from Montana's border, an aerial survey last year failed to find any of the hogs. 

At a summit hosted by the Montana Invasive Species Council on Friday, University of Saskatchewan researcher Ryan Brook showed aerial photos of what appeared to be simply a muddy patch breaking up a snowy landscape. 

Feral pigs

Ryan Brook, associate professor at the University of Saskatchewan and director of the Canadian Wild Pig Research Project speaks at a conference on the threat of feral pigs in Montana at the Northern Hotel on Friday.

But there were pigs buried in the mud, outed only because one had a radio collar. They'll also burrow into snow, creating "pigloos" — actually the technical term — to help ride out harsh winters. 

Officials plan to conduct another round of flights this winter once snow cover hopefully makes the pigs easier to spot than during the leafy cover of warmer weather. 

But they're also asking Montanans to keep their eyes peeled. The flights may not have found feral pigs, but this is an animal that can go on a 25-mile run. 

"All of the pieces of information we have is that, yeah, (border crossing) does happen," Brook said. 

Who you gonna call?

It seems obvious, but reporting sightings of the pigs is critical. The state will soon launch a "Squeal on Pigs" campaign, mirroring a previous effort in the Pacific Northwest. It urges anyone with information to call the Department of Livestock at 406-444-2976. 

From there, information needs to be shared among government agencies. For example, a predator control program coordinates with state agencies to access land. The group has agreements with ranches to kill animals like coyotes or bears that damage crops or kill livestock, and it's now adding feral swine to the agreements as they're renewed. 

Feral piglets

Feral swine are prolific breeders, producing an average of six in a litter and breeding year round with a gestation period of less than four months. 

Officials also noted that "squeal" does not mean shoot, and emphasized that on-the-down-low hunting of any feral swine that settle in Montana could make the problem worse

The Montana law that prohibits the hunting of feral swine also requires people to report sighting of the animals within 24 hours. But officials were hoping to create an enthusiastic spirit for reporting rather than a compulsory grumble.

Some attendees were optimistic that the message would sink in. 

"Ranchers are really concerned," said Maggie Nutter, who leads the Marias River Livestock Association. 

John Steuber, who leads Montana's branch of the federal predator control program that would likely be a go-to for killing feral hogs, was optimistic that recent success stamping out fledgling sounders (the term for a pack of pigs) in other states could translate to Montana. 

Feral pigs

A "sounder" of feral swine includes piglets and adult females, including one dominant female. 

"Montana is well-situated to deal with this issue," he said. 

The program has aircraft available already used to hunt predators like coyotes, he said, and can look to Canada and other states to learn lessons about trapping feral swine. 


There's good reason to keep feral swine out of Montana. The animals can wreak economic and environmental havoc. 

The disease-spreading facts are somewhat uncertain about feral swine. They're known to carry and spread swine strains of several diseases like brucellosis or leptospirosis, plus diseases like pseudo-rabies and hepatitis. But researchers are also studying the potential for pigs to spread diseases like chronic wasting disease or even anthrax. 

There are seemingly infinite indirect effects. For example, damage from rooting could create more mosquito habitat, increasing the risk of bloodsucker-borne disease. Or pigs could compete with ungulates like deer and change migration patterns, affecting diseases like CWD. 

“We could talk all day," about disease potential, said state department of livestock veterinarian Anna Forseth. 

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Feral piglets

Feral swine are prolific breeders, producing an average of six in a litter and breeding year round with a gestation period of less than four months. 

Swine behavior like rooting can destroy cropland or even places like golf courses or residential landscaping. The pigs are basically "vaccum cleaners" that consume 3-5% of their body weight each day. They've got favorite foods, often high-dollar crops like watermelons or lettuce, but will eat just about anything with calories — even fawns and songbirds. Brooks said some research has shown that they'll take additional risks to chow down on their favorite meal — in Canada, "corn is king."

Damage is huge in the southern United States. The most recent USDA estimate put swine damages at $1.5 billion each year, but the agency has stopped putting an exact number on losses, said Dale Nolte, who leads a USDA feral swine damage program. That's because it’s difficult to determine, but it’s likely at $2.5 billion now, he said.

There are even traffic wrecks to factor in. Feral swine cause $36 million a year in vehicle damage. 

Feral pig hoof print

Feral pigs have hoof prints that look similar to deer but are more rounded. 

"Hitting a feral pig is like hitting a 200- to 300-pound-rock on a highway," Nolte said. 

Pigs also destroy habitat that native species have evolved in tune with. They can consume food sources from other animals, to the point that even squirrels have been stressed after pigs raided their buried nut and seed caches. What that looks like in Montana, and especially with large mammals, is unclear. 

There are infinite combinations of food chain disruptions, possible predation of specific species, and the likelihood that landscape damage makes it easier for invasive plants to take root. 

There is one safe bet; the pigs are unlikely to become a major food source for predators like wolves or grizzly bears. Brook knew of only one documented wolf kill of a feral pig in Canada. 

Feral pigs

Anne Miller of the Montana Pork Producers Council speaks as part of a panel at a conference on the threat of feral pigs in Montana at the Northern Hotel on Friday, November 15, 2019.

“I don’t think anything’s going to mess with a sounder of 28 animals,” he said, citing a recent trail camera image of a group.

Jennifer Ramsey, a wildlife veterinarian with Montana Fish, Wildlife and Parks, saw feral swine fallout firsthand while attending college in California. 

"At that point my (thought) was, this was an overwhelming problem and we'll never catch up," she said. "If we could avoid getting to that point, it would be great."