Study Finds Development Is Restricting Grizzly Bear Movement

A new study tracking the movements of more than 100 grizzly bears across the southern Canadian Rockies offers a clearer, and more concerning, picture of how human development is quietly reshaping where and how these animals move.

Drawing on two decades of GPS data, researchers mapped how bears navigate a landscape increasingly defined by roads, towns and industrial activity. Their conclusion is straightforward: the more humans build, the harder it becomes for bears to move freely, and that has long-term consequences for their survival.

“Understanding wildlife responses to human disturbance is essential for developing effective conservation and management strategies,” the study notes .

A landscape that looks open, but isn’t

At first glance, the southern Canadian Rocky Mountains still appear vast and wild. But for grizzly bears, the study suggests that much of that landscape is becoming fragmented in subtle but important ways.

Researchers analyzed movement data from 109 GPS-collared bears across an 85,000 square kilometre region spanning southeastern British Columbia and southwestern Alberta. They then simulated how bears would move under three scenarios: a landscape without human disturbance, current conditions, and a future with more development.

What they found is that even existing infrastructure is already limiting how bears move.

“Comparisons of predicted space use and movement success… highlighted the degree to which highways have impeded grizzly bear movements,” the report states .

Bears don’t just avoid highways outright. In many cases, they won’t cross them at all.

Both male and female bears consistently avoided crossing highways in every season. Towns, large bodies of water, and rugged high-elevation terrain also acted as barriers, effectively funneling animals into narrower and narrower corridors.

Drawn to danger

One of the more counterintuitive findings is that bears are sometimes attracted to the very places that put them at risk.

In areas where natural food sources are limited, bears were more likely to spend time near roads and highways, where vegetation tends to be more abundant due to open sunlight and disturbed ground.

“Bears whose home ranges had lower vegetation productivity strongly selected areas closer to highways and roads,” the study found .

That creates what researchers describe as an “ecological trap,” where animals are drawn to food-rich areas that also expose them to higher risks, including vehicle collisions and human conflict.

In other words, the landscape is nudging bears into dangerous decisions.

Not all bears behave the same

The study also found clear differences in how bears respond to human activity, depending on sex and season.

Female bears were generally more cautious, especially in spring and summer, when they were less likely to move through towns. Males, on the other hand, were more willing to take risks and travel through developed areas.

Seasonal behavior also matters. In the fall, when bears are trying to pack on calories before winter, they are more likely to enter valley bottoms and even residential areas in search of food.

That increases the chances of human-bear encounters at exactly the time when bears are most motivated to take risks.

Connectivity is quietly breaking down

The biggest concern raised by the study isn’t just where bears go, but how easily they can move between places.

Scientists use the term “functional connectivity” to describe how well animals can travel between different parts of their habitat. It’s critical for finding food, mating, and maintaining healthy populations.

The study found that this connectivity is already declining.

Across a key region in southeastern British Columbia, about 80% of movement pathways between habitat areas showed reduced connectivity under current conditions compared to a landscape without human disturbance.

On average, movement success dropped by about 10%.

And the trend doesn’t stop there.

When researchers modeled a future scenario that includes expanded towns and new mining activity, connectivity declined even further.

“Additional footprints of proposed mines and expanded human settlements… were predicted to further decrease functional connectivity for grizzly bears,” the study states .

Why it matters beyond bears

The implications go beyond individual animals.

When movement becomes too restricted, populations can become isolated. That limits genetic exchange, reduces access to resources, and increases the risk of local population declines.

The study warns that if connectivity continues to erode, some areas could become “sink” habitats, where bears die faster than they can reproduce.

“If future human-caused habitat alteration impedes functional connectivity… grizzly bear populations in these sink areas will decline,” the report states .

This matters not just for bears, but for the broader ecosystem. As a wide-ranging species, grizzlies play a role in shaping the environment, and their movement patterns often overlap with other wildlife like elk, black bears and wolverines.

Protecting their ability to move helps maintain the health of the entire system.

A narrowing window for action

Despite the concerning trends, the study also points to solutions.

Protecting key movement corridors, reducing attractants in developed areas, and building infrastructure like wildlife crossings could all help maintain connectivity.

The challenge is timing.

Once movement corridors are lost, they are difficult, and sometimes impossible, to restore.

“Safeguarding the movement of grizzly bears in this region… is important,” the study notes, pointing to other regions where connectivity has already been lost and is unlikely to return .

For now, the southern Rockies still function as a connected landscape, at least partially. But the study makes it clear that this is not guaranteed to last.

What looks like a vast wilderness from above is, from a bear’s perspective, becoming a maze of barriers, trade-offs, and increasingly risky choices.