Grey wolves have a big impact on the communities of plants and animals around them. That’s why we call them a keystone species. Like the “key stone” that holds an arch in a building together, wolves keep the animals and plants around them in balance. Without them, ecosystems are less biodiverse (which means they have fewer different animal and plant species) and less healthy.

Before Europeans came to North America, many Indigenous groups had important relationships with wolves. They admired how these animals work together as families, and some treated them as teachers, guides or even brothers. But when European settlers arrived, they cleared land to make farms and raise livestock. To them, these fierce predators were nothing but a threat to their sheep, goats and other farm animals. We can still see their fear of wolves in stories like The Three Little Pigs and Little Red Riding Hood.

After colonization, settlers killed many wolves and took over their habitats. Then, something surprising happened: a chain reaction that affected wildlife, plants and even landforms (the natural features of Earth’s surface like hills, valleys and plains). With fewer wolves — the apex predator at the top of the food chain — the populations of prey species the wolves used to eat, like elk and beavers, exploded. They ate up the plants that were holding the soil in place. The soil started washing away and flooding increased. The whole ecosystem suffered.

Today, we know how important wolves are. Scientists have reintroduced them in many places, like Yellowstone National Park in the U.S. With wolves to control the prey populations, the plants have been able to recover. This has, in turn, slowed down the erosion of soil because the roots help to hold it together.

In Canada, wolves now live in 80 per cent of their original range. Populations in some places have shrunk, especially around cities. But in the north, roads and pipelines have let wolves travel more quickly to access prey, so some populations have grown. Overall, the number of wolves in Canada is staying about the same.