[troutman]

Hinterland Who's Who:

http://www.hww.ca/hww2.asp?id=82

Every fall, beavers in northern latitudes construct food caches, or piles, in deep water close to the lodge or bank den they have constructed. Each cache is an accumulation of the beavers’ favourite woody food items, and it is meant to sustain the beavers in the winter. With the first frosts of September and October, the animals begin to prepare the cache by clearing trees away from the edge of the water. If the area is relatively free of predators, the beavers take their logging operation farther afield—often 125 m away. They gnaw the trees into short lengths and tote them to the water, along trails that they have cleared, for underwater storage.

The bulk of the edible forage, or food, in the cache is held below the water surface by a thick top layer of small, leafy branches most often cut from trees and shrubs that are not the beavers’ most preferred (see Figure 2). The top layer protrudes well above the water surface, where it intercepts snow to provide an insulating cover that prevents water from freezing in and around the stored food.

Figure 2: Beaver lodge, food cache, and dam in water