Food

Beavers are herbivores and will eat almost any eatable vegetation they can find on the banks of a river or pond (Dzieciolowski and Misiukiewics, 2002). However, beavers prefer certain species of vegetation over others. The Castor fiber has been reported to prefer bark and leaves of willow, hazel, and birch (Dzieciolowski and Misiukiewics, 2002). The Castor canadensis, as reported by a source from Canada, prefers the bark and leaves of willow, birch, poplar, aspen, cherry, maple, and alder (“Beaver: Canadian Domain,” 2004). Another source which surveyed beavers in the Smoky Mountains reported that the Castor canadensis also ate sweet gum, magnolia, and dogwood (Linzey and Brecht, 2004). Again the diet of beavers depends largely on availability, and preferred species reported from different areas reflects this (Dzieciolowski and Misiukiewics, 2002).

Beavers in the more northern latitudes experience harsher winters than those in southern latitudes; therefore, to assure an adequate food supply during the winter beavers in the north must construct food caches (Wheatley, I. Seasonal Variation, 1997). Food caches are stockpiles of food that beavers build up in the summer and fall in preparation for the winter when their ability to leave the lodge is severely limited (Wheatley, I. Seasonal Variation, 1997). In colder climates beavers spend most of the winter in the lodge and under a layer of ice that coats the water (Wheatley, I. Seasonal Variation, 1997). Therefore it is important for the lodge to have an underwater opening that leads to the cache for easy access (Dzieciolowski and Misiukiewics, 2002).

Beavers will arrange a food cache so that larger, heavier branches on the top of the pile will anchor smaller branches at the bottom. This is primarily to prevent the smaller branches from getting swept away by a current especially in rivers. However, it is also so the ice on the surface of the water does not trap the smaller, more eatable branches. (Dzieciolowski and Misiukiewics, 2002)

Food Cache Diagram

Adapted from Dzieciolowski and Misiukiewics, 2002

There is also a possibility that beavers leach their food to make some the hard-to-digest species more eatable. A study conducted by Mueller-Schwarze et al. in 2001 hypothesized that beavers process their food to make it more palatable. The study concluded that beavers do in fact leave certain species of tree branches in water for up to three days before ingesting. This process of leaching is used for especially difficult-to-digest species such as hazel trees (Dzieciolowski and Misiukiewics, 2002). The process of leaching may draw out toxins from the wood that would otherwise be harmful to beavers' digestive systems (Dzieciolowski and Misiukiewics, 2002). Food caches may play a role in this leaching process, as they keep branches submerged for an extended period of time (Dzieciolowski and Misiukiewics, 2002).

 

Home Page	General Information	Habitat	Food	Predators
Social Spacing	Mating System	Social Organization	Works Cited	Contact