Wallowing in the wild

Tuesday, April 6, 2021

Escaped pigs have managed to hybridize and proliferate in Canada, with disastrous consequences for agriculture.

by Jackie Clark

Bob Brickley first encountered wild pigs two decades ago. He farms in southeast Saskatchewan, growing grain, raising cattle and keeping a large purebred-based quarter-horse herd.

"About 20 years ago, some pigs escaped from a domestic farm and started invading our premises and upsetting our whole operation," he tells Better Pork.

"At that time there were only 14 pigs doing this, and it was an incredible experience and we learned very quickly that if we had large numbers it would be devastating to our operation."

Brickley started hunting the wild pigs − and he made an assumption that this would be an easy job.

"We were humbled by these animals and it was an incredibly challenging undertaking," he explains.

"They reproduced, increased in numbers and spread their territory into some inaccessible areas within Moose Mountain Provincial Park. It became very apparent that this was nothing like we'd ever experienced before. They'll outsmart you and outmanoeuvre you, especially where the terrain is more suitable for them than the pursuer."

Brickley organized some local producers into an eradication effort. He would locate the groups of pigs, called sounders, from the air and then call the producers to organize and hunt.

"We had a lot to learn, and we made every mistake possible in that process, but we did learn how to eradicate these sounder groups," he says.

"We had to have a lot of confidence that we could eradicate an entire group before we would move on them."

Over the years, the team learned and became more effective "and in the end, over a 20-year period, we've eradicated pigs in this area," Brickley says.

The problem is wild pigs continue to reinvade the region.

The current situation

For many years, Canadians did not consider wild pigs to be much of a problem.

In 2010, "we started putting out trail cameras, and we found that there were pigs running around in the wild," says Dr. Ryan Brook. He's a professor in the college of agriculture and bioresources at the University of Saskatchewan and has been studying wild pigs for the last decade.

Initially, some people assumed escaped pigs wouldn't survive in the harsh winter conditions, Brook explains. However, he soon observed through trail cameras that pigs were reproducing in the wild.

Though population estimates are uncertain, Brook has mapped the range of wild pigs in the Prairies.

Currently they "are expanding at over 80,000 square kilometres (32,000 sq. miles) per year," he says. "The distribution across Canada is one million sq. km (400,000 sq. mi.) and that's bigger than most countries."

Population "densities are relatively low compared to the southern United States, but I think that it's probably a matter of time, given the reproductive rates and survival rates that we're seeing, that densities will continue to increase. These animals are feeding on agricultural crops all summer and even into the fall," Brook explains. "They put on good body condition and then they can survive really well through the winter."

Pigs "are incredibly smart and capable, and they're also highly mobile," he adds. "We've been GPS collaring them for years now, and one thing that's exceedingly clear is that they have these very large home ranges."

Wild pigs can cover 300 to 400 sq. km (120 to 160 sq. mi.) in one summer, says Brook.

Wild pigs in Canada are not genetically homogenous. They include European wild boars, which likely escape from penned shooting operations, explains Brook. They can also be escaped domestic pigs from commercial operations or pet owners.

However, hybrids between European wild boars and domestic breeds are "the overwhelming majority," he says.

With cross-breeding "you get a much larger animal and higher reproductive rates."

Because of this heterogeneous population, Ontario's Ministry of Natural Resources and Forestry (MNRF) defines wild pigs as "any pig that's found outside of a fence," Bree Walpole tells Better Pork. She's a senior policy adviser in the fish and wildlife policy branch of the ministry.

In Ontario "the number of wild pigs in the province remains relatively small," she says.

"To date, the majority of sightings that we've received are from southern and eastern Ontario, but not all of those sightings have been verified. Our preliminary research indicates that wild pigs are not established in Ontario at this time."

The MNRF asks citizens to continue to report sightings so the ministry can monitor the situation.

"Many of the sightings appear to be escaped domestic pigs or pot-bellied pigs," adds Walpole.

Destructive animals

Wild pigs "can have a negative impact on the natural environment and the agricultural industry, including impacts to native plants and animals through predation and competition," Walpole explains.

Potential also exists for wild pigs to "spread diseases to livestock as well as native wildlife."

Brickley has witnessed the damage to crops first-hand.

"It's not so much what they eat, it's what they destroy in the process," he says. "After they're done with it, no one will eat it, it's tromped on and there's urine and feces on it, and it's just a total write-off."

The pigs also disrupted Brickley's cattle, who would typically swath graze through the winter.

"They dislodged our cattle from our winter feed supply," he explains. He had to relocate the cows and find an alternative feeding strategy. His horses were impacted as well.

"Horses are very afraid of pigs," he explains. "Horses are just terrorized … and once they're afraid in a certain area, they won't go back."

He witnessed both pigs and horses crash through fences on his farm.

Another risk factor to consider is the potential for wild pigs to act as a disease vector.

Brook's research team is currently "looking very carefully at the spatial overlap and interaction between wild pigs and domestic pigs, and concern for disease," he says. "There has not been much testing of wild pigs in Canada and there's been this general disinterest to test wild pigs for disease, which I think is quite dangerous."

Brook thinks the industry is hesitant to test wild pigs because "there's a real concern about what happens if you find something."

"I think all of us learned a lot or were changed dramatically by BSE," and might fear the impact on the industry if wild pigs in Canada tested positive for certain diseases.

But "if you don't know, then there's nothing you can do about it," he says. "You really can't ignore these issues – you have to take them head-on. So far there hasn't been a lot of action from the swine industry."

Industry experts recently observed the spread of African swine fever (ASF) by wild pigs in Germany.

If ASF "does come to North America, it would probably come to domestic animals first. But the potential for it to get into wild pigs and wild pigs be a reservoir and a vector for a disease like ASF could be catastrophic to the industry," says Brook.

Lessons from the U.S.

Producers and government officials can learn from the successes and failures of eradication attempts from our southern neighbours.

"Feral swine have been in the U.S. for centuries," explains Dr. Dale Nolte, the feral swine program manager for the Animal and Plant Health Inspection Service (APHIS) agency of the United States Department of Agriculture.

"Spanish explorers would release them as they explored so that the pigs would survive and they'd have a food source as they returned. But it was probably in the '70s or the '80s that we started seeing populations building up, and then this exponential growth has probably happened from the mid '80s till now."

Officials "strongly suspect that people are moving them around – that's how they're getting into new areas," he says. People may continue to contribute to the spread because they want pigs for sport hunting.

APHIS has employed field staff to control wild pigs since the late '70s, "but in 2014 Congress put money in the federal budget to create a feral swine program," he explains. That funding has allowed for more research and increased eradication efforts.

Initially, experts estimated that wild pigs annually caused US$1.5 billion (C$1.9 billion) in damage, Nolte says. New research suggests "it's probably significantly greater than that. It probably always was – we just didn't recognize it."

One of the main challenges with eradication, and a reason why sport hunting is an issue, is that controlling wild pigs necessitates getting rid of an entire sounder at once.

"Feral swine are very intelligent animals so, if you can catch them all right up front, you're better off than if you only catch a few of them, because every time you miss a shot, you train them to avoid a trap or humans," Nolte explains.

Wild pigs, of course, don't stay within the bounds of a state or country.

"It's a massive problem that's going to take tremendous co-operation to address," Nolte says.

Brickley agrees. Wild pigs are "a far broader thing than just a regional, area, provincial or even a country thing. On this continent we have to view it as a continental problem or challenge that we have to work on collectively," he says.

In Ontario, officials "are working with a number of partners both within the province and from other jurisdictions and we're consulting with them to learn about what's worked and what's been successful from their eradication programs," says Walpole.

Regions that don't have a major feral swine problem should take preventive action, Nolte says.

Paul Mussell, a grain and maple syrup producer from Ottawa-Carleton, Ontario, agrees.

Five years ago he attended a wildlife control operators' convention in North Carolina.

"I was blown away by the amount of damage (wild pigs) were doing and how quickly they spread throughout the United States," he says. "We have them in Ontario − it's something we have to deal with."

Previous strategies

"Every single province has responded very differently," says Brook. "Manitoba acted very early and, in 1991, they turned the whole province into a wild boar control zone where you can shoot them on sight. Manitoba was by far the most proactive in the early times."

Manitoba trained people to trap and shoot pigs in the '90s "until they were mostly eradicated. They did an excellent job," he explains.

"If you're really serious, then you'll have a control plan. Alberta is the only province in Canada with a strategy."

Sport hunting "is probably the biggest barrier to success of any control program. I believe that the sport hunting of wild pigs has actually been one of the major factors helping spread them around the landscape," Brook adds. "You can have sport hunting or you can have eradication, you can only pick one."

If you shoot pigs without eradicating the entire sounder, the survivors move to new areas and get better at avoiding hunters, he explains.

"The best option would be to eradicate all these wild pigs but, unfortunately, now the distribution and the abundance means eradication of wild pigs in Canada is no longer feasible," Brook says.

"But there are huge areas of the country that can either remain wild pig-free … or become wild pig-free or stay (relatively) wild pig-free like Ontario and B.C."

One of the challenges of legislating control of wild pigs is the fact that "they kind of fell between the cracks for a long, long time because technically when they're in the wild they're not livestock anymore," says Brook.

Neither the agriculture nor wildlife agencies of the government can take sole responsibility of control efforts.

Continued work

As places with existing infestations continue eradication work, other regions should act proactively.

In Ontario, "it's important that if farmers see wild pigs, they report them," says Mussell.

The swine industry should develop more policy around escapes and traceability, he adds.

"There should be a fine."

The MNRF in Ontario is "taking a proactive approach and preventing the establishment of wild pig populations in the province," says Walpole. "We are continuing to urge the public to report wild pig sightings, as it's an important source of information for us."

The ministry conducts on-the-ground follow-up of reported sightings, engages with residents, and is setting up trail cameras in places where they suspect wild pigs are living.

"Where appropriate, the ministry is prepared to test approaches for trapping and removing invasive wild pigs from the environment," Walpole adds.

"Since January 2020, wild pig researchers have investigated 22 locations in southern and eastern Ontario where 66 sightings of wild pigs were reported."

As of December, "nine wild pigs have been successfully removed from the environment and the ministry has also learned that, for several of the high-priority sightings that were investigated, pigs have returned to their enclosures or were otherwise recaptured or removed from the environment," she explains.

Ministry officials continue to monitor sighting locations to assess if further actions are needed and consult with the public about how invasive wild pigs should be regulated.

"Getting ahead of the game can have huge advantages," Walpole points out.

Farmers' role

Wild pig eradication "is going to be a very collective process," says Brickley. "Government has to be involved, of course, but we have to take leadership ourselves as producers. Industry has to be involved. We have to take this seriously and recognize the potential that's lurking before us and we have to develop a will to deal with it. Everyone needs to take ownership and recognize what will happen if something isn't done."

Mussell agrees.

"We've got to work with the MNRF, but agriculture has to step up with some money because we're going to be devastated similar to the United States if we do nothing," he says.

Producers can take steps to protect their operations.

"Fences are one of the best and most effective tools," says Brook. Farmers may want to install "fencing where feed is being loaded and unloaded where there might be some spillage."

Perimeter fencing is also "not a bad investment of time and energy," he adds.

Even if producers don't believe they have wild pigs in their area, "get some trail cameras and put them out around their farm," says Brook. The nocturnal animals can be hard to spot.

"Once you start seeing them, you already have a major problem," says Brickley. However, his self-organized efforts give reason for hope.

"We did what many people, almost everyone, said couldn't be done." BP