26 BULLETIN 10*78, IT. S. DEPARTMENT OE AGRICULTURE. 



but after a few years, when the aspen and other choice foods are cut 

 back for 8 or 10 rods from the shore, the tendency of beavers is to 

 hunt for new quarters. When the supply becomes low on beaver 

 farms, aspens or other desirable trees or bushes, when cut and hauled 

 to the shores, provide an ample supply of food for summer and win- 

 ter at little expense. By occasionally burning cut-over areas at the 

 proper season a new supply of aspen would spring up. From in- 

 formation available it appears reasonable to estimate that a section 

 (640 acres) of good aspen land ought to feed 1,000 beavers indefi- 

 nitely if well managed. 



Many other trees, bushes, and plants (see p. 6, under Tree Cut- 

 ting for Food) are eaten by beavers and should be included in their 

 food for the sake of variety. Coarse water grasses, rushes, sedges, 

 and cat-tails are extensively eaten in summer, and waterlily rootlets, 

 stems, and leaves are a choice food. Clover and alfalfa are eagerly 

 eaten and could be raised on the slopes near the water as a supple- 

 mental food supply. Young beavers are especially fond of red-clover 

 heads, lily-pads, and cowslips, and of the leaves and twigs of aspen, 

 hazel, pin cherry, willow, mountain maple, striped maple, and vari- 

 ous birches. As they grow older they eat more bark, and in winter 

 their main food consists of bark, leaves, and twigs from the wood 

 cached under water. Some roots and green vegetation may also be 

 found along the shores and on the bottoms in winter. Both young 

 and old beavers are fond of bread, rolled oats, and cracked corn, and 

 possibly of other grains also. The effect of a variety of foods on the 

 size and vigor of animals and on the color and quality of fur is a 

 problem for future study. 



Artificial houses should be provided where a new colony is started. 

 A plank or log house 4 feet square with a hole in the bottom and a 

 door in the back may be set over the edge of the pond with the bottom 

 just touching the surface of the water, so the beavers can come up 

 inside. A metal trap door opened and closed with an iron rod from 

 the outside can be fitted over the water hole, so that the beavers can 

 be shut in and examined at any time. If kept in this house over- 

 night or a day before being released they will come back to it and 

 use it regularly. 



Under normal conditions beavers never deposit their feces except 

 in the water, where they sink to the bottom or dissolve and disin- 

 tegrate. I have never been able to find a trace of them in the houses, 

 not even in those occupied by young, nor on the banks or shores. In 

 captivity the beavers often hold their pellets as long as possible if 

 no water is at hand, and unload them as soon as they get into water 

 again. For this reason they should always have access to clean or 

 running water. 



