Climate change could shorten bear hibernation periods, lead to more human interactions

In the High Sierra, bear encounters are expected. But several bear sightings have been reported in more urban Northern California landscapes this year. According to bear behavior experts, there are a couple of reasons why this may be happening and both are related to factors that drive a bear's hibernation instinct. "Hibernation is a response to food shortage," said Heather Johnson, an animal research biologist with the USGS Alaska Science Center.