U of S researcher sounds alarm on wild pigs

A researcher from the University of Saskatchewan is calling for action to drive back wild pigs that have spread rapidly across Canada.

Ruth Aschim, a Ph.D candidate at the U of S College of Agriculture and Bioresources, did a first-of-its-kind study mapping out the area occupied by wild pigs across Canada.

“Prior to this, we knew that they were in Canada in, kind of, the Prairie provinces, but we really didn’t know where,” she said.

Aschim’s report, published in the Nature Scientific Reports journal, found that wild pigs are found across an area  of some 777,783 square kilometres — or roughly the size of Saskatchewan and Newfoundland combined.

“And I found an exponential increase in their range expansion and a really rapid increase,” she said.

Eurasion wild boars were brought to Canada in the 1980s and ’90s as a way to diversify livestock, in hopes of selling more meat to Asia.

However, Aschim said the market never took off the way many producers had hoped and many of the animals either escaped into the wild or were simply released because they weren’t profitable.

She said the boars’ interbreeding with domestic pigs created a hybrid wild pig that spreads even more rapidly.

“Domestic pigs are bred to have much larger litter sizes, whereas a true Eurasian wild boar, the average litter size is four to five, sometimes six,” Aschim said.

Aschim is concerned that not many people truly understand the destruction invasive wild pigs wreak on the ecosystem. She said the pigs tear up the ground with their snouts as they root for food.

“It’s a roto-tiller-like effect, it really just upturns all the vegetation.” she said.

She said the pigs can also contaminate water where they wallow and defecate. Plus, she said the pigs pose a risk to crops and can potentially spread disease to livestock — potentially fouling international trade.

“We can look to the U.S., where they say it’s about $1.5 bllion in crop loss and damage per year just from wild pigs. Then they also have vehicle collisions with wild pigs which they estimate at $40 million per year,” she said.

Aschim said it may still be possible to eradicate the pigs, particularly in areas where they remain in smaller, localized populations. But she said sport hunting likely won’t be the solution.

“You need to kill over 80 per cent of the population to actually cause a decrease in that population. You need to do that annually. But sport hunting only kills about eight to 24 per cent of the population,” she said.

What’s worse, she said wild pigs are smart enough to adapt to hunters.

“It educates them and then they’ll move to a new area and change their activity patterns and they will become even more wary and elusive towards humans, as well as become almost exclusively nocturnal,” she said, noting that some U.S. jurisdictions have actually banned sport hunting of wild pigs as part of their eradication strategies.

Aschim said it would take co-operation between multiple levels of government to run the kinds of sustained, organized trapping campaigns needed to catch and kill the pigs.

“We really need that aggressive management,” she said. “And, I also think a national framework is kind of something that we need to aim towards; we’re seeing that pigs really don’t respect our boundaries.”