Beaver, Beavers, Castor canadensis, fauna, eat, eating, nourishment, gnaw, gnawing, chew, chewing, survival, food, North American wildlife, wildlife, Rodent, Rodents, aquatic, aquatic mammals, Water, Pond, Ponds, Wetland, Wetlands, Marsh, Marshes, horizontal, North America, Fall, Autumn, aspen, aspens, Kitchin, Hurst, Mammal, Mammals, bark, tree bark, wet