It is a WoodChuck; AKA: Groundhog, Land beaver, Whistlepig, Marmot
Identifying characteristics: A large ground squirrel with a stubby and chunky body. The fur is a grizzled brown. The tail is bushy and a bit darker than the rest of the body. It is also smaller in proportion to other squirrels. The eyes are large and black and the ears are small and round.
Size: From 16 to 27 inches in length and weighing about 8 lbs.
Habitat: Meadows, pastures, old fields, farmland and wooded areas. Prefer grassland with close cover. Mowed lawns near wooded areas are preferred. Burrows are usually in sandy or soft soil and are used for escaping predators. Second burrows are often built below the frost line for hibernation. Nesting chambers are often lined with dry leaves.
Food: Herbivores. Primarily grasses, herbs, leaves, bark, buds and twigs. Will also eat farm crops such as corn and alfalfa.
Vocalization: Very vocal squirrels. They are known for their whistle which alerts other of threats (hence the name "Whistlepig"). Barks, squeals, and chirps are also common.
Predators: Humans, birds of prey, coyotes, lynx, weasels, snakes, foxes.
Reproduction: Litter size average 3-4 with 1 litter a year. Mating season is in spring. Young stay with their mother for 6 weeks.
Other Info.: Active mostly during the morning and late afternoon (diurnal). They are solitary and aggressive animals but may be found grazing in small groups and sharing burrows. Unlike other squirrels in our area, these hibernate in winter. Woodchucks are excellent climbers and swimmers and can often be spotted in trees if you look hard enough.
http://en.wikipedia.org/wiki/Image:Marmota_monax.ogg