Fundamental to the survival of Yellowstone National Park's grizzly bears is a sufficient supply of four key foods: meat, cutthroat trout, moths, and white bark pine. Not only do these foods provide vital nutrients, but the location of the food helps keep grizzlies safe from humans. Due to various factors, the supply of each of these foods is either gravely threatened or faces an uncertain future. This video from Nature examines these four foods as they relate to the survival of the grizzlies of Yellowstone.

This video is available in both English and Spanish audio, along with corresponding closed captions.