National Geographic : 1974 May
MOVER AND SHAPER, the beaver excels at transforming its domain to suit its needs. Feeling safe only in water, it creates its own pond-cutting logs, transporting them, and raising a barrier across a selected stream. Aspens in an Arizona forest (below left) look as if Paul Bunyan had been at work. Actually, beavers standing atop four-foot-deep snow left the six-foot stumps. With powerful incisors, a beaver gnaws through a tree (left) as relentlessly as a chain saw. After felling a tree, a beaver cuts it into manageable pieces and hauls them to the damsite. It builds the dam base of logs and stones, then wedges sticks under the rocks with free ends leaning in the direc tion of the current. After weaving a latticework of brush, the animal scoops mud from the stream bed to plaster the dam face. Sediment and debris carried downstream help fill crevices. Constant repairs keep the dam from washing away. The sound of rushing water seems to alert the beaver to breaks. Carrying a stick, a pond-sleeked re pairman (below) sets out to plug a hole.