212 



MAMMALS OF AMERICA 



States. The result is that it has become abun- 

 dant in certain regions and is common in others. 

 This is notably true in Colorado and Wyoming. 

 In Maine and in the Adirondacks of New York 

 State it is increasing rapidly. In Estes Park, 

 Colorado, it is especially numerous, one holding 

 of looo acres having a population of 600 or 

 more. 



\\'ith proper protection and well enforced laws 

 regulating its capture there is no reason why the 

 Beaver should not become again a source of 

 pleasure and of profit over much of its early 

 range. 



Excepting Rats, Mice and Rabbits probably no 

 rodent is so well known. Tlie Beaver's industry 

 has become proverbial ; his fur is familiar to all, 



hands. The hind feet have the same number of 

 toes and are webbed for swimming. In passing 

 through the water the hind legs do the propelling, 

 assisted sometimes by the sculling action of the 

 tail, and the front legs are held against the 

 sides. 



The broad tail is not used as a trowel, as was 

 formerly supposed, but is a rudder. ]\Ir. Enos 

 A. Mills states that sometimes mud is trans- 

 ported by being held between the tail, which is 

 turned under and forward, and the under side 

 of the body. 



In these days of animal persecution the Beaver 

 is nocturnal, but in localities where he is 

 thoroughly protected he may be seen at almost 

 any time during the day, particularly toward 



By permission of the New York Zoological Society 



AN ALERT BEAVER 



The engineering feats of the Beavers in building two sets of dams 

 and feeder canals are among the most remarkable achievements 

 of the lower animals 



and his habits have made him a subject of much 

 interesting literature. 



The Beaver exceeds all other North American 

 rodents in size. A fairlv large one will weigh 

 from thirty-five to forty pounds, and a few will 

 go to fifty or sixty pounds. In shape the Beaver 

 is squat and broad, resembling, in a general way, 

 a Musk-rat, but is at once distinguishable from 

 that animal by its broad tail. Two broad, chisel- 

 like teeth in the front of each jaw enable him to 

 cut wood with great ease and rapidity. These 

 teeth are beveled on the inner surface and are 

 self-sharpening, because the inner softer surface 

 wears away faster than the harder outer surface. 

 The fore-feet have five toes and are used as 



late afternoon. In a lake not far from Yellow- 

 stone Park the writer has often seen several 

 Beaver at once swimming about. In Estes Park 

 he has seen them at all hours of the day. One 

 has only to sit quietly beside a Beaver pond to 

 see one or more within a short time. 



No mammal approaches the Beaver in the ex- 

 tent or the variety of the structures which it 

 makes. He is the engineer of the mammal world. 

 These works not only involve highly developed 

 instincts, but, some writers believe, indicate a 

 great degree of adaptive intelligence. Certain 

 it is that the Beaver seems to use reason in 

 modifying his structures to meet new situations. 



Of all the Beaver's works his dam has at- 



