BBC自然世界：阿拉斯加的灰熊 Grizzlies of Alaska

A mother grizzly bear brings up her two cubs in the wilds of Alaska. She must keep them safe from prowling males, teach them to hunt and prepare them to survive the savage winter. Alaska has the highest density of grizzlies in the world, so fights and face-offs are common. Biologist Chris Morgan spends the summer in this land of bears, often getting far too close for comfort.