Animals have the amazing ability to survive even the harshest of circumstances. Some animals hibernate (go into a deep sleep) so they can survive throughout the cold season when the weather is freezing and the food is scarce. Hibernation truly is a clever survival mechanism.
We all know about the bears and their ability to sleep through the winter. But have you heard about the wood frogs?
These incredible creatures freeze upwards of 60% of their bodies during the winter months. It can survive for weeks wit two-thirds of its body water completely frozen—to the point where they are essentially solid frogsicles.
Even more cool is the fact that the wood frogs stop breathing and their hearts stop beating entirely for days to weeks at a time.
In fact, during its period of frozen winter hibernation, the frogs’ physical processes—from metabolic activity to waste production—grind to a near halt.
Researchers have discovered that the reason for this the miraculous phenomenon is the high concentration of cryoprotectants in the wood frog’s tissues. These are solutes – including glucose and urea – that lower the freezing temperature of the frog’s cells, helping them survive.
In most animals, exposure to subzero temperatures for a long time could cause cellular shrinkage. During this process, water is pulled from the body’s cells to form ice, eventually sucking them dry and killing the cell. But with wood frogs, cryoprotectants help the cells resist shrinkage.