Rocky Mountain Outlook: American researchers are hoping to embark on a study to find out if climate change is playing a role in grizzly bears heading into the dens later each year and emerging from their winter slumber earlier than ever before. Following more than 20 years of data on collared grizzly bears in the Greater Yellowstone Ecosystem, researchers say they have noticed a troubling trend that could suggest grizzlies are changing their winter hibernation patterns. There are concerns the fate …