There are two noticeable differences in the appearance of an active beaver lodge in the fall as opposed to the summer. One is the presence of a growing pile of freshly-cut branches adjacent to the lodge. These branches provide resident beavers with the nutrition they will need during the winter months when herbaceous plants are neither available nor accessible.
The second change noticeable in a fall lodge is the presence of massive amounts of mud. Branches are often placed on top of this layer of mud, so you have to observe the lodge before that happens in order to see the extent of the mud layer. It provides protection from harsh winter winds which would significantly lower the temperature inside the lodge. Together, a blanket of snow and a layer of mud serve as excellent insulation for beavers living in the lodge.
In the Northeast, where the temperature often dips into the single digits or lower in the winter, the interior of an active beaver lodge maintains a relatively stable 33° F. – 35° F., roughly the temperature of the water, thanks to the ingenuity of these rodent architects.
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