Famous for determining how long winter will last, groundhogs or woodchucks, as they are also known, hibernate throughout the winter months in a grass lined nest underground. Its body temperature drops as low as 37° F, just above freezing, to slow its metabolic rate and food demands.  Its heart beats only 4-5 times a minute and it breathes only once every four minutes.  With its body slowed down it can go without food or water for almost five months.  Emerging in the spring, as temperatures warm and plants grow again, the woodchuck consumes at least one pound of greens a day.  By summers end it has doubled its weight in preparation for hibernation.