Wildlife Corridor Science

We live in one of the last towns on Earth that co-exists with grizzlies and other large wildlife species — it's kind of a big deal.

Canmore's mountainsides provide a key link in the network of protected areas within the greater 3,000-km Yellowstone to Yukon region of the Rockies, one of the last intact mountain ecosystems in the world. 

Navigating the valley, though, is a complex challenge for animals like grizzlies, wolves, elk and others whose range includes the area between protected habitat in Kananaskis Country and Banff National Park, and beyond. Wildlife face a number of pressures as they try to survive here, most of which are related to an ever-growing human footprint: the Trans-Canada Highway, the railway line, residential areas and industrial developments. They now span the full width of the valley bottom and on to the lower slopes on both sides of the valley. 

With little room left to move, animals are forced to the edge, higher up the mountain slopes, in an attempt to avoid this man-made obstacle course and reach safer ground in the parks on both ends of Canmore.

By designating, maintaining and respecting the importance of functional wildlife corridors that allow animals safe passage, we help to ensure that wide-ranging animal populations remain connected, healthy and genetically diverse.

Leading by example

Since major development began in the 1990s, local and regional conservation initiatives — and the depth of scientific knowledge that has surfaced through the work — have put Canmore on the world stage as an environmental leader. There's now decades of data, analyses and knowledge that can be applied to discussions about wildlife corridors and how to make sure they will be effective.

Knowing we live in one of the last places on the planet with the full range of large mammal species that have thrived here for hundreds of years, conservationists are asking: How do we avoid the breaking point when animals no longer use the Bow Valley as a connector? How much pressure can they withstand before we have major impacts on their populations?

It's impossible to know for sure so conservationists and wildlife scientists, both locally and around the world, are urging Canmore to err on the side of caution. Mountain towns in similar situations are watching to see if Canmore can figure this out, if we can get it right.

Concerns with the Three Sisters corridor

Scientists state the current design of the Three Sisters corridor will not support wildlife movement — let alone improve it. Large-scale development proposed for this area threatens to sever the centuries-old, heavily used routes and patterns animals use to navigate the Bow Valley. 

Generally, criticism from ecologists is that the corridor is too small, too narrow and too steep to work effectively. There are pinch-points where the corridor is narrower than 70m wide between developable land and the slopes Alberta Environment and Parks determined are too steep for most large animals to travel on.

A 2015 review of local wildlife tracking data by ecologist Dr. Adam Ford shows most large wildlife living in the area spend 95 per cent of their time on slopes flatter than 20 degrees. Slope matters.  

At Three Sisters Village Centre, dense commercial and residential development is proposed for the unfinished golf course, encroaching upon what has become a functional and well-trafficked wildlife corridor. The decision notes that the criteria upon which the corridor was evaluated set out to “not block wildlife movement” to say nothing of improving it. 

In addition, housing is now proposed for where the across-valley wildlife corridor at Stewart Creek currently is. The 2020 proposal suggests relocating it to an area that can’t be developed because of steep creek hazard flooding risk. This in itself raises concerns amongst scientists and the community how suitable it would be for wildlife.

Since 1992, the science behind, and our understanding of, wildlife corridors, connectivity, and movement has expanded significantly. Leading corridor ecologists Paul Beier and Adam Ford recently released research on how corridors should be planned to help wildlife thrive.

Little of this is reflected in the 2020 proposals.  

The bigger picture

The concept of a wildlife corridor, which is well-known to many of today's residents in Canmore, was not really understood 20 years ago when the Yellowstone to Yukon Conservation Initiative (Y2Y), a Canmore-based organization now internationally recognized as a leader in wildlife corridor connectivity and conservation around the world, first took root in the valley. 

Since that time, our home in the Rockies has been identified as one of the last intact mountain ecosystems on Earth that continues to share the space with all of the wildlife species that have been here for millennia.

Because grizzly bears in particular require a vast amount of territory, in principle, if the grizzly populations are thriving the rest of the animal populations will be as well. For this reason, many scientists today use the health of grizzly bear populations as their guide in measuring the health of the whole ecosystem.

“Over the last 20 years, collectively we have been able to double the protected areas, mitigated hundreds of miles of busy highways, and helped grizzly bears expand their ranges for the first time in over a hundred years,” Karsten Heuer, who was president of Y2Y from 2013 to 2015, said in an interview with Highline Magazine.

New study shows wildlife struggle to navigate busy Bow Valley

An article by Cathy Ellis in the Rocky Mountain Outlook in March 2021 highlights a new interagency study that shows wildlife connectivity for wolves has decreased in the Bow Valley by 25 per cent and for grizzly bears by 21 per cent since historic, pre-development times.

“The landscape of the Bow Valley is already very degraded for wildlife movement,” said Mark Hebblewhite, one of the study’s authors and a professor in the wildlife biology program at the University of Montana in Missoula.

“We found if Three Sisters builds out and the town of Canmore has a whole bunch of new development, we’re going to see an additional six per cent reduction in connectivity.”

Setting the standards for corridors

In light of the rapid population growth associated with expansion in Canmore and the surrounding area, a number of new environmental groups formed in the 1990s to tackle the issues at hand including the Bow Corridor Ecosystem Advisory Group (BCEAG) established in 1995. This group — a partnership between the Government of Alberta, the Town of Canmore, Banff National Park and the Municipal District of Bighorn — published the Wildlife Corridor and Habitat Patch Guidelines for the Bow Valley in 1998. The document identified guidelines for land managers that could be applied as a consistent approach to development applications and provided standards for wildlife corridor and habitat patch design. In 1999 the BCEAG guidelines received a Premier’s Award of Excellence and were reviewed and updated in 2012. 

Since the guidelines came into play in 1998, Canmore has used them to determine effective wildlife corridors and habitat patches, including the Canmore Nordic Centre, Silvertip's wildlife corridors, the Bow Flats habitat patch and others (although not the Three Sisters corridor — see below).

The graph shows the formula developed through BCEAG for determining effective corridor width. For a corridor one kilometre in length, a base width of 350 metres is required. For every additional kilometre of length, an additional 100 metres of width is required in order for animals to effectively use the corridor.