Frozen Wood Frog survives the winter in Alaska

A sequence filmed by UK wildlife cinematographer Steve Downer for Denali - Alaska's Great Wilderness, a film in the PBS series The Living Edens. The Wood Frog ( Rana sylvatica ) survives the winter in suspended animation underground. With its body frozen, the frog shows no signs of breathing or a heartbeat. A natural form of antifreeze prevents the insides of the frog's cells from freezing and causing tissue damage. In the spring the frog thaws out and resumes normal activity.