Island Living for Grizzlies is No Day at the BeachSep 15, 2011
Grizzly bears need healthy, connected habitats to survive in the wild.
The seemingly endless mountains and rugged valleys of British Columbia, western Alberta and the northwestern United States may at first glance look like vast stretches of prime grizzly habitat, but the reality is that for many bears they might as well be marooned on a desert island.
Over the past three centuries, as human development crept further and further west, grizzly habitat was developed for mining and logging, carving it into smaller and smaller pieces surrounded by roads, farms, railroads and towns.
All of these human barriers made it challenging for bears and other wild animals to move around. The once vast areas of grizzly habitat dwindled into tiny pockets – or islands – of wilderness. As even these islands disappear all that’s left to the bears now are the mountainous regions to the north and west; the areas where fewer people venture. This “islandization,” or the isolation of animal habitat through human activity, creates anything but a day at the beach for grizzlies. It has disastrous effects on the wildlife that today find their final refuge in what’s left of the once great wilderness of North America.
The few remaining Alberta grizzlies – less than 700 – live precariously on the eastern edge of the habitat for western Canada’s grizzlies. The border between western Canada and the U.S. now forms the southern edge of the main North American grizzly range, with a single island population still hanging on in the region centred on Yellowstone National Park. The historical shrinking of grizzly habitat continues today – with one important difference explains Wendy Francis, Program Director with the Yellowstone to Yukon Conservation Initiative (Y2Y): “today we see grizzly habitat shrink In real time. We watch habitat disappear and too easily find examples of true ‘islands of habitat’ in places like Swan Hills, where the entire grizzly population has been reduced to only 23 bears.”
"Island life" for animals is not the tropical getaway we equate with that term – it can be difficult and dangerous.
Is it too late? Are these marooned bears doomed to eventual extinction? “When animals are trapped on pieces of land, no matter how big, it’s really the beginning of the end,” explains Francis. “Extinction and genetic isolation are the long-term threats because animals can’t interact with others of their own species. It’s not just physical isolation, it’s also inbreeding that is not healthy for the long term.”
“Island life” for animals is not the tropical getaway we equate with that term – it can be difficult and dangerous. Grizzlies must navigate their way through towns and cross highways, motorized paths and railways increasing the likelihood they will come into contact and conflict with people; they all too often die in the process. Physical isolation limits the gene pool and ultimately makes them more vulnerable to disease and catastrophic events like floods and fires.
Securing new areas of core habitat, such as the Castle Wilderness Area next to Waterton National Park in Alberta, and reconnecting areas that have become disconnected (like Yellowstone National Park in the U.S.) are the focus of several conservation organizations, including Y2Y. “The big picture is that we need to maintain the connectivity of the landscape at a large scale. Animals need to be able to move, have space and not be confined to these man-made islands – even if they’re big ones,” says Francis.
People are the direct cause of this “islandization.” People must fix it. Connected areas of well-managed, good quality wildlife habitat allow animals, including grizzly bears, wolves and cougars, to travel freely – they need space and some room to breathe. An adult female grizzly bear searches for food in a home range of between 152 and 2932 square kilometres, while male grizzlies may need to cover much larger areas – between 501 and 4748 square kilometres – simply to find food sources and a mate.
Good-quality habitat benefits not only bears, but other animals and plants that share their ecosystem. “It’s too expensive and impractical to study and manage every bit of nature so we need to pick the best indicator or ‘umbrella species’ and manage the habitat for them knowing that in doing so we’re also protecting other valuable parts of nature that benefit both animals and people,” says writer and conservationist Jeff Gailus, author of The Grizzly Manifesto.
“Grizzlies and people can coexist,” says Gailus. “It’s not a matter of completely eliminating human activity, it’s about making sure our activities – recreational and commercial – have minimal impact and are sustainable.”
Just 300 years ago, grizzlies roamed almost half of North America. Huge brown bears lived on the Great Plains as far east as the Mississippi River or south well into Mexico. Then, habitats were connected and animals moved unhindered, creating opportunities for breeding that resulted in genetic diversity and healthier wild populations for many animals – not just grizzlies.
As published in the Fall 2011 issue of the Calgary Zoo’s Wild Life member magazine.