Researchers have found that grizzly bears are falling into an “ecological trap” in the Canadian Rocky Mountains. The area has abundant resources and little competition, luring grizzly bears who end up falling prey to hunters and cars while causing problems for people. The findings are in a paper that was just published in the Journal of Animal Ecology.
An ecological trap is a low-quality or dangerous habitat that is attractive to animals due to novelty, abundant resources, low competition, and other factors. Apex predators are very vulnerable to these traps because they lack natural predators and tend to be less cautious. Grizzly bears are attracted to the East Kootenay region in British Columbia. Huckleberries and buffaloberries, both nutritious and rich in energy, are plentiful in the area. Grizzly bears have been rapidly disappearing, however, and researchers wondered if they were falling into a trap.
A team of scientists analyzed data from the past nine years. They found that grizzly bears were common in areas with plenty of berries, which tended to overlap with human activity. While some bears were killed by hunters, the majority of deaths were due to collisions with cars, trucks, and trains. The high mortality rate led to a smaller bear population in the area, attracting new bears to take their places. The authors note that this effect is unfortunately common.
The study’s findings show that most grizzly bear deaths in the studied areas of the Canadian Rocky Mountains were due to human activity. The bears were lured to the area because favorite foods, such as huckleberries, were common. These resources and a lack of competition attracted the bears to an ecological trap, where they risked being killed by vehicles or hunters. The bears also wandered close to human settlements, creating a potential hazard to people. The authors hope that their study will help reduce human impacts on populations of grizzly bears and other predators.
Clayton T. Lamb et al. Forbidden fruit: human settlement and abundant fruit create an ecological trap for an apex omnivore. Journal of Animal Ecology (2016).