These two young Grizzly are no doubt a little late getting to the den this past year but the photo illustrates why they need to!
They head into their dens for months at a time, then they come out in the spring looking a whole lot thinner and hungry for sure!
They do this because of the scarcity of food all winter. In Alaska our snows are deep and last for many months. The ONLY way they survive is hibernating. Look at all the money we could save on food and diet loss programs if we could do this! We are pretty sure this is true by studying smaller mammals that hibernate because waking sleeping bears to study this is not a good idea!
They do wake occasionally to move around but quickly head back into a deep sleep.
During hibernation, Bears reduce their body temperature to a point that approaches or even falls below the freezing point of water. (Salty body fluids have lower freezing thresholds that keep tissues from freezing) Overall metabolism drops to about 98% — just 2 degrees above dead.
