"Also known as the Groundhog or the Whistle-pig, the Woodchuck thrives in forest borders through much of the eastern United States, across Canada, and into Alaska. Socially, Woodchucks live singly from the time they are weaned at six weeks of age. They are diurnal vegetarians, consuming clover, dandelion, chickweed, alfalfa, sorrel, beans, peas, grains, grasses, and other plants. In their burrows, they sleep through the night, raise their young, and spend the winter in hibernation. When it is hibernating, the Woodchuck's body temperature drops almost to the air temperature in its den and its heartbeat slows from 75 beats per minute to about 4. Curled into a tight ball, with its head between its front legs, it seems to be dead."

Links:
Mammal Species of the World
Click here for The American Society of Mammalogists species account