Parks Canada is celebrating some new mothers this year, ones that haven’t lived in the wild of western Canada in 140 years. Three bison babies wobbled their way into the world two weeks ago with thick red fur and gangly legs, marking a critical milestone in the rehabilitation of their species within Banff National Park.

These bison calves are part of a Parks Canada five-year pilot program to reintroduce wild bison into Canada’s first national park. A herd of 16 bison, 10 of them pregnant, were helicoptered in from Elk Island National Park in February 2017. They are now in an 18-hectare paddock in the backcountry of Banff National Park, where they will remain until summer 2018.

The first bison calf was born on Earth Day, April 22, and the other two followed a few days later. The hope is to reinforce with the mothers and calves that this land is their home so that when they are fully released into the park next year, they will stay within that area.

According to Bill Hunt, resource conservation manager for Parks Canada, the place where a mother bison births her calf is where she and the baby are most likely to return to, even if the mother was born elsewhere. They will have a tie to the land.

“It would be really special if we can get wild bison back,” says Hunt. “Bison have been a missing piece of our food web here for a long, long time.”

Bison are what scientists call a keystone species. Like Grizzly bears and beavers, their presence in an ecosystem has ripple effects on several other species of both plants and animals.

Daniel Fortin, a professor at Laval University in Quebec, has studied bison for 20 years. He says that bison are a critical part of Parks Canada’s objective to restore “ecological integrity,” which aims to maintain ecosystems in their natural state. “We cannot really talk about the ecological integrity of western Canadian ecosystems without the presence of plains bison,” says Fortin. “This reintroduction and those births are therefore very positive.”

Fortin says he is excited to watch the growth of this herd, with seven calves still expected this season, and to see how the herd develops in the coming years. Updates will be posted Banff National Park on Facebook and Twitter.