The bears, named Grinder and Coola, have lived in a mountain shelter in North Vancouver, BC, since 2001. At 171 days, that was the biggest winter slumber in 21 years, Grouse staff said. Mountain Resort in a press release. . The grizzlies were “greeted with applause” as they emerged from their hideout on Thursday morning, staff said. This is the second consecutive year that their hibernation has broken a record. Last year the bears, which usually hibernate for about four months, rested for 170 days. Prior to that, their record was 153 days. “Hibernation during the winter is a natural way for grizzlies to save energy during a period of low food availability,” director and veterinarian Ken Macquisten told the news release. During this period, they are monitored by staff using video and infrared cameras. Grinder and Coola were found apart as orphans in 2001 and live in a 5.5-acre shelter on top of Grouse Mountain. The bear habitat has two cameras so that the public can watch their actions, but the wildlife sanctuary is also a tourist attraction. Video from the outdoor camera on Friday morning showed one of the bears loading wood around its enclosure, which is still covered in snow.