The Eastern box turtle, Terrapene carolina, is the largest known freeze-tolerant vertebrate. Life's pulse in the Northern Hemisphere is already growing faint. Plants are scattering their seed and dying or going dormant. Birds have flown south to warmer climes. Down they go, to lake bottoms and underground dens, to silent caves and chambers deep in the dark, cold soil, to slumber, living off energy stored in their bodies.
Mammals head for cover beneath the frost line.
Bullfrogs, mink frogs and leopard frogs sink into ponds and streams to wait out winter under ice in a sort of liquid-cooled coma. But wood frogs, chorus frogs and tree frogs wriggle into wet soil near the surface and let sub-zero temperatures turn them into living ice cubes. Studies show that in the coming months, as much as 65 percent of their total body water will freeze. In this state, the frogs show virtually no movement, breathing or heartbeat, yet they will revive fully within minutes of thawing next spring. Just how they manage to stay intact is one of nature's great puzzles and the focus of Storey's research in Ottawa.