The food habits of mountain beavers are closely tied to the dominant vegetation in their habitat. Sword fern and bracken fern are preferred when available. Douglas fir, hemlock, western red cedar (Thuja plicata), and red alder are all commercial tree species that are cut and eaten by mountain beavers. Other species found in their habitat are either eaten or used for construction of nests. Most feeding occurs above ground within 50 feet (15.2 m) of burrows, although occasionally mountain beavers may travel several hundred feet from burrows. They routinely climb shrubs and trees 8 feet (2.4 m) or higher to cut off branches up to 3/4 inch (1.9 cm) in diameter, where they leave cut stubs of branches on trees.
Mountain beavers also girdle the base of tree stems and will feed on stems up to 6 inches (15 cm) in diameter, as well as the root systems of large trees. The bark is found in the stomach contents of animals collected in midwinter. Woody stems are often girdled and cut into about 6-inch (15-cm) lengths. Food and/or nest items are often stacked at burrow entrances but are sometimes carried directly to food caches or nests. Plant material is occasionally eaten outside the burrow but is usually eaten at the food cache, in nests, or in the burrow. Mountain beavers practice coprophagy (consumption of feces) and select soft over hard pellets.
Resources: (online)
Mountain Beavers
