Richard Lydekker

“ The materials made use of are driftwood, green willows, birch and poplars; also mud and stones intermixed in such a manner as contributes to the strength of the dam, but there is no particular method observed, except that the work is carried on with a regular sweep, and that all the parts are made of equal strength. “In places,” writes Hearne, “which have been long frequented by beavers undisturbed, their dams, by frequent repairing, become a solid bank, capable of resisting a great force both of ice and water ”

“ The American species is also greatly diminished in numbers from incessant pursuit for the sake of its valuable fur. Beavers are sociable animals, living in streams, where, so as to render the water of sufficient depth, they build dams of mud and of the stems and boughs of trees felled by their powerful incisor teeth. ”

“ Their houses are formed of the same materials as the dams, with little order or regularity of structure, and seldom contain more than four old, and six or eight young beavers. It not unfrequently happens that some of the larger houses have one or more partitions, but these are only posts of the main building left by the builders to support the roof, for the apartments have usually no communication with each other except by water. ”