Fragmented habitats and climate change threaten Sask species

SCIENCE by Gregory Beatty


Stewards Of Saskatchewan
Royal Saskatchewan Museum
Monday 21

Saskatchewan’s population is relatively small, but since the early days of settlement, humans have extensively altered the prairie habitat. Grain farming, ranching and, more recently, aggressive oil, gas and other extraction industry development have changed this place at an astounding pace.

But for millennia before that, native animal species relied on the grasslands for food, shelter, nesting and hibernation. In a Darwinian world driven by natural selection, the margin between life and death is always thin, and a stable environment was critical to survival.

Not surprisingly, many species have had trouble adapting to the “new” Saskatchewan.

“The last study in 2009 showed there was only 21 per cent of our grasslands left,” says Rebecca Magnus, Nature Saskatchewan’s habitat stewardship coordinator. “In the far southwest there’s tens of thousands of acres of untouched prairie that can provide habitat for a wide variety of species, but as you get further north and east, that gets broken up and fragmented.”

And that can be a problem.

The Wildlife Act (1998) uses four terms to classify at-risk species: extirpated, endangered, threatened and vulnerable (extirpated might be a new one to some readers; it means a locally extinct species that continues to exist elsewhere).

The black-footed ferret, greater prairie chicken, Ord’s kangaroo rat, burrowing owl, piping plover, greater short-horned lizard, little brown bat, gypsy cuckoo bumble bee, dusky dune moth, Western spiderwort and lake sturgeon are only a few of the Saskatchewan species that are in trouble.

Magnus is one of the people tackling the problem. In February, she and her Nature Saskatchewan colleagues attended a two-day Saskatoon conference on conservation and endangered species.

“It filled us with a wealth of scientific knowledge to help us when we go out and talk with our stewards,” she says. “They always have these questions: ‘How are the populations doing? What do they need and what can we do for them?’”

The stewards she’s talking about are members of Nature Saskatchewan’s Stewards Of Saskatchewan program, which has around 730 participants — mostly landowners and land managers.

“We work with a wide variety of stakeholders,” says Magnus. “Some are more indirect and hands-off, while others are incredibly keen to do hands-on enhancement to conserve biodiversity on their land.”

The stewards play a critical role in conservation, says Magnus.

“There’s no way we could visit all the sites they do each year,” she says. “They provide us with data which contributes to the bigger picture of decision-making and gives information to developers, industry and recovery teams to guide their activities.”

While those efforts are welcome, habitat is much more complex than our legal concept of property.

“When it comes to conservation, it’s not just about every owner’s small parcel of land,” says Magnus. “Since 2000, we’ve done around 120 enhancement projects to break down the fragmentation that’s occurred.

Habitat fragmentation is a significant threat to many Saskatchewan species. When a large area is carved up to be developed, it can mess up migration and make it harder for animals to find food and mates. A population can be isolated, which often means it’s at higher risk from things like droughts, fires, floods and disease.

While habitat fragmentation also happens naturally, human activities like building roads, farming and mining can cause drastic fragmentation in short periods of time.

“We can’t do anything about roads; they’re always going to be there,” Magnus says. “But if there’s a quarter section of native habitat and there’s other suitable habitat a kilometre or two away, we can work with the landowners to make a connection by maybe putting some cropland into permanent cover. Then that can function as a bridge to expand the habitat.”

Unfortunately, for many species, re-establishing sustainable populations is an uphill battle.

“At the conference we had a presentation by Grasslands National Park on the black-footed ferret,” says Magnus. “People have gone to great lengths to reintroduce it, and it seems there haven’t been any ferrets observed in two years even though there was mating and offspring. But then a plague came in. It not only wiped out the Grasslands population, it hurt recovery efforts across the plains so none are left in the wild.”

Conservation efforts are now focused on ridding prairie dog colonies of the plague, says Magnus, because that’s one way it spreads to ferrets.

“Hopefully, if they can get rid of it, they can try the reintroduction effort again,” she says.

Then there’s the burrowing owl, an adorable bird that’s had well-publicized struggles. With support from Prince Philip, no less, Operation Burrowing Owl (which has been around since 1987) has grown to encompass 150,000 acres at 504 sites. But in that time, OBO has documented a dramatic plunge in the burrowing owl population of 96 per cent!

Looming on the horizon is another threat to prairie plant and animal species: climate change.

“Climate change is inevitable,” says Magnus. “We’re already experiencing it. This year, for instance, we’re probably going to experience a fair drought that will impact a lot of species.

“Before that, we had four or five years of very wet conditions that can be good for some species but not others. Burrowing owl burrows, for instance, were flooded, so it wasn’t great for them.”

Ungulates such as deer and elk were hit hard by heavy winter snow packs in the wet years. And while they generally benefit from mild winters like this one, other species that hibernate — such as bees and bats — suffer because they come out of hibernation early with no food and water sources.

As with property lines, habitat doesn’t stop at the U.S. border. The good news there is that international co-operation is happening in conservation, says Magnus.

“There’s a trans-boundary effort between Saskatchewan, Alberta and Montana looking at biodiversity with the understanding that there are no borders for species and that there is a need to partner with all the stakeholders to conserve the habitat and promote their survival,” she says.

In July, she says, Saskatoon will host the first International Rangeland Congress ever held in Canada.

“The last couple were in Argentina and China, and brought over a thousand people together who all have a stake in rangeland management and prairie conservation. The soils and plants might be different than our mixed grasslands, but there are similarities in the challenges we face and how we go about mitigating them,” says Magnus.

Conservation at Nature Saskatchewan isn’t limited to the stewardship program, Magnus says, and she invites hikers, campers and other outdoor enthusiasts to get involved.

“There’s a huge movement among the public to be part of citizen science and it’s our responsibility to ensure they have the proper tools and knowledge when they go out to recognize what’s there,” she says.

“If somebody does see a species they find interesting, we encourage them to call us or send a picture and background details,” says Magnus. “We have a privacy policy where we don’t share personal information.

“It’s a really easy number: 1-800-667-HOOT or e-mail”

On March 21, Magnus will speak at the Royal Saskatchewan Museum on Nature Saskatchewan’s stewardship program, which promotes habitat conservation and monitors at-risk species.