Jan. 9 (UPI) -- Want to save the lives of grizzly bears? Close more roads. That's the advice offered by a new study published this week in the Journal of Applied Ecology.
The roads, of course, aren't the direct threat. Humans are. The closer grizzly bears are to humans, the more likely they are to die. And roads ensure humans and grizzly bears are closer together.
When scientists at the University of Alberta looked at the link between road densities and grizzly bear densities, they found a direct correlation. The more roads, the smaller and more spread out the grizzly bear population.
"The problem with grizzly bears and roads is a North American-wide issue," Alberta scientist Clayton Lamb said in a news release. "This is the first study that strongly links roads to decreased grizzly bear density."
Bears die near roads, but aware of the dangers, they also avoid roads. This makes the habitat surrounding roads less effective. Roads effectively shrink the amount of wilderness available to grizzly bears -- a species whose habitat is already shrinking as a result of deforestation and climate change.
"By closing roads, we can reduce the negative impact of roads in a lot of ways," said Lamb, who is currently working toward his PhD with University of Alberta conservation biologist Stan Boutin. "We can't turn roads back into forest tomorrow, so the best thing we can do right now is to close them. The effects are immediate."
Lamb and Boutin looked at the health of the grizzly bear population in British Columbia's Monashee Mountains, just east of the Okanagan, where, following the abolishment of grizzly hunting, the bear population is beginning to recover.
"It is more important than ever that the public recognize the continuing threats to bear populations. Current road densities in British Columbia represent a problem for bear conservation," Lamb said. "We are losing wilderness in the province, and there are fewer grizzly bears where road densities are high. We're taking it another step further and advising that closing roads will do a lot to improve bear populations."
The research has already inspired new road closures in the Monashee Mountains. Lamb says the work is applicable to habitat throughout North America -- anywhere humans and bears share the land.