214 



MAMMALS OF AMERICA 



used less and the burrows more. When harassed 

 they are less likely to make houses. 



Of all the works which show the skill of the 

 Beaver, many regard his canals as showing his 

 intelligence to the fullest extent. Many animals 

 build homes, and the dam has a direct connection 

 with the safety of the Beaver home, but the 

 canal has no direct connection with either. It 

 is a structure planned with a definite end in vie\\', 

 that is, the greater ease in transporting food. 

 When all suitable trees near the borders of the 

 pond have been cut, it becomes increasingly 

 difficult to get sticks from the source of supply 

 to the storage pile in the home pond. At the 

 expenditure of much energy the stick must be 

 rolled, pushed and dragged for a distance, in 

 some cases, of a quarter of a mile or more. To 

 avoid this, when the ground is suitable, a colony 

 of Beavers will often dig a canal in the direction 

 of a grove of trees. According to circumstances 

 such a canal may be from a few feet to several 

 hundred in length. Its depth varies from about 

 fourteen inches to over three feet, and its width 

 is two feet or slightly more. Beavers will on 

 occasion dam the canals and also construct lateral 

 ridges to direct surface water. This further 

 evidence of engineering skill would be astonish- 

 ing were it the only trait of this extraordinary 

 animal. 



Canals are sometimes dug in the bottoms of 

 shallow ponds. These make travel and trans- 

 portation easier in times of low water, and afford 

 avenues of travel when the ponds are frozen 

 nearly or quite to their bottoms. 



The food of Beaver has been indicated al- 

 ready. It is the bark of many kinds of decidu- 

 ous trees, especially aspen, willow and birch. 

 Roots of water-lilies, grasses and even berries are 

 also eaten, but bark is the staple. Evergreen 

 trees are sometimes cut for structural purposes, 

 but the bark is not eaten. 



Since the Beaver cannot climb, he must fell 

 trees in order to get any large supply of food 

 without traveling to great distances. This he 

 does by gnawing, for which his four great chisel- 

 shaped front teeth are well adapted. A tree two 

 to eight inches in diameter is usually selected. 

 The worker sits bolt upright with his tail 

 stretched out behind, as a prop, and proceeds 

 to cut in such a manner that, just before 

 the tree falls, the cutting resembles the central 

 part of an hour-glass. When once seen it can 

 never be mistaken. As the tree is about to fall 

 the Beaver woodchopper slaps the ground with 

 his tail as a warning to others, and all get to 

 places of safety. The branches are trimmed oflf 



next, the trunk cut into lengths of from three to 

 six feet or more, and are dragged and rolled to 

 the pond or canal through which they are floated 

 to the food pile near the house. Here they are 

 sunk to the bottom and held there by a little mud 

 and by other pieces piled on top. The diameter 

 of the trees cut tisually is not over eight inches, 

 and the record is thirty inches, btit the writer 

 has seen three narrow-leafed cottonwood trees 

 in one group, varying from twelve to fourteen 

 inches in diameter, all of which had been felled. 

 Only branches less than eight inches in diameter, 

 however, had been used. 



The Beaver, contrary to common report, does 

 not always succeed in making a tree fall in a 

 given direction. Many pictures are extant show- 

 ing trees in helter-skelter position. 



After the bark has been eaten during the 

 winter the sticks are used for house and dam 

 building, if needed. 



Beavers are monogamists and, apparently, mate 

 for life. Mating takes place in February, and 

 the young are born in May. In a month they 

 can live on solid food, and at two years of age 

 are capable of mating. The number of young in 

 a litter averages about four, but it may be any 

 number from one to eight. 



The following pleasing glimpse of the Beaver 

 at home is given by Dan. J. Singer: "As we 

 were passing a small pond of perhaps lOO yards 

 in diameter, I caught a transient glimpse of a 

 Beaver through the thin blue ice as he darted 

 into the tunnel which led to his house. This 

 low-domed house ( which looked very much like 

 the house our musk-squash builds) was built of 

 mud, turf and sticks cleverly interwoven, and 

 rising about three or four feet above the sur- 

 face of the ice. At one end of the pond they 

 had their customary dam, as well as a gieat 

 store of food to guard against the winter's 

 famine. At a point in the dam they had de- 

 posited this food supply, which consisted chiefly 

 of willow branches cut into convenient lengths. 

 At feeding time one slips out of the house and 

 swims down through the pale amber water to the 

 brush-pile, selects a suitable stick and returns to 

 dine on its tender bark. And so, all through the 

 long, savage winter, the little chaps live, play 

 and feed — all below the frozen upper world. 



" The Beavers are not without their enemies, 

 however, and, perhaps, the most feared is that 

 long, squat, shambling animal, with a triangular 

 head and two cruel leering eyes — the Wolverine 

 or Glutton. With just about six rakes of his 

 rascally claws he could demolish the entire house , 

 once the ice has ceased to protect it, but presto! 



