Many scientists place the black bears living on Vancouver Island in separate sub-species (Ursus americanus vancouveri). Apparently, these island residents have been isolated from their mainland counterparts for about 10,000 years, which has allowed them to become somewhat genetically distinct. Their appearance is different from other British Columbia black bears too: their pelts are a bit darker, and they tend to be a bit larger in size. Most people think that black bears spend the winter hibernating, but this isn't technically true. Scientists call the black bear's winter resting time a state of torpor. This state is similar to hibernation, but instead of being completely sedated, the animal will wake if it senses danger or urgency. Some black bears on Vancouver Island may not rest at all during the winter months, depending on how cold their surrounding environment is and how available food may be. And some bears may choose to go into a state of torpor for only a short period of time, resting during a particularly bleak stretch of weather or when food availability is extremely low.