The Problem with Pigs – Part I

I have been reading the stories about wild pigs in Manitoba with some interest over the past year. More specifically, I have been wondering how these furless omnivores survive Manitoba’s winters.

Perplexed, I did some research about wild pigs, particularly about their native range. I thought it might be useful to put these agricultural and ecological pests into perspective by looking at their origins, their ecological needs, and how they are able to make Manitoba home.

To begin with, whether you call them wild pigs, European boars, or wild Texas boars, they are all the same species, as are our domestic pigs. They all share the same Latin name, Sus scrofa. All these pigs derive from the Eurasian wild boar, domesticated somewhere in eastern Europe or western Asia.

This also means that you can “reverse-evolve” tame pigs to look and act like wild boars over a few generations. When I was a kid on the farm, our pig herd consisted of a mix of Yorkshire, Landrace, and Duroc breeds. And while the piglets all looked like the cute babies you would expect, the older they were, the uglier and more brutish they appeared, with some of our largest boars pretty much indistinguishable from their wild cousins.

If you examine the original range maps of European wild boar, they were found in most parts of Europe south of the North Sea, with the core range centred around Ukraine, southern Russia, and extending to points south to the middle east and beyond.

These areas provide all the conditions necessary for wild boars. Rooting under nut-producing trees allow pigs to find enough calories in these rich foods, even during the winter. They also scavenge on dead animals, as well as dig into the soil to find wild tubers and to eat fungus such as truffles.

The relatively mild winters mean that, unlike Manitoba, the soil isn’t frozen solid, and the temperatures are moderate enough (no colder than -10 C) that the pigs can feed all night long, which lessens the danger from predation. Snow, when it falls, is generally short-lived and rarely builds up to depths that make it hard for short-legged pigs to move through.

If you plotted the climate of their original range in eastern Europe, and compared it to North America, these animals would live in an area equivalent to the U.S. mid-west and areas south, occasionally extending as far north as the southern Great Lakes, such as Lake Erie.

This is not what you find in Manitoba in a normal year, especially this year. This is worth repeating. The Canadian prairies and parkland are not normally fit habitat for wild boars. Our winters are too long, too cold and lack easily accessible natural food during the winter, such as nuts.

These conditions are why another similar-sized omnivore, the black bear, decides to skip the winter through hibernation. Black bears are much more well suited for our area. They can gain hundreds of pounds of fat during the summer, they have lots of thick fur, and they are adapted to sleep for more than five months during the coldest months.

And just as importantly, they can climb trees to access food such as acorns or aspen catkins. With the ability to stand on their hind feet, they can also access berries still in the tree, such as chokecherries and hawthorn apples. This means that they can get to food before it drops to the ground. Pigs, with the exception of the ability to pack on the pounds, do not possess these special tools.

On a related note, when working as a park interpreter, I was asked more than once whether pigs and bears were closely related. After all, they are both omnivores, eating much the same things, and they even share the same names for males (boars) and females (sows).

Alas, pigs are not closely related to bears at all. In terms of the ancestral tree, humans are more closely related to bears than pigs are. And I assume that most people wouldn’t consider themselves to be closely related to bears, or pigs for that matter!

In case I am making too strong a point about their poor adaptions for life in Manitoba, let me highlight some of the pig’s strong points. To begin with, pigs have large litters, and they are smart, quickly learning to adapt to new situations. As pointed out by Dr. Ryan Brook at the University of Saskatchewan, they use what he has termed “pigloos,” structures of cattails, long grass, and snow that protect them from the coldest weather.

They are also evolved to avoid predators such as wolves which can control pig populations but not eliminate them. Pigs will also travel long distances to feed each day, and their snouts provide them super sensitive smelling, allowing them to find even buried food. As stated, they also have a very catholic diet, meaning just about everything is a source of food to them.

Despite these strengths, pigs still shouldn’t be able to overcome the challenges of Manitoba. Yet, there is definitely a breeding population of wild pigs here in Manitoba. How are they able to survive, and even reproduce here? I will cover this topic in next month’s article, where I will delve into the factors that allow them to persist here, and the current management techniques for controlling these wild pig populations.

» Ken Kingdon lives in the heart of the Riding Mountain Biosphere Reserve. Send him a text at 204-848-5020 if you have stories to share.