86 



NORTH AMERICAN FAUNA 66 



Distribution in Maryland. — Formerly occurred in all sections of the 

 State, but was exterminated around the turn of the century or earlier. 

 It has been deliberately restocked in some lareas and naturally invaded 

 others from neighboring States where animals were stocked or rem- 

 nant populations survived. 



Distinguishing characteristics. — Teeth 1/1, 0/0, 1/1, 3/3, = 20; 

 largest rodent in Maryland; body thickset and compact; legs short; 

 ears small; hind feet large with the toes webbed; tail broad, flat, 

 nearly hairless, and covered with large scales; pelage with very soft 

 dense underfur, overlaid with long coarse guard hairs; coloration dark 

 rich brown above, lighter below. 



Measurements. — "Nine adults from the Allegheny National Forest, 

 Pennsylvania, average: Total length, 1,031 mm. (970-1,090 mm.); 

 tail vertebrae, 358 mm. (260^40 mm.) ; greatest width of tail, 129 

 mm. (112-150 mm.) ; hind foot, 169 mm. (156-183.)." (Handley and 

 Patton, 1947, p. 158). 



"The skull is large and massive, that of the adult more than 120 mm. 

 long and 85 mm. broad ; . . • length of upper molar series about 28 

 to 30 mm." (Jackson, 1961, p. 192) . 



Habitat and habits. — This species prefers forested areas wherever 

 there are suitable watercourses for the construction of dams and 

 lodges. The sluggish fresh- water streams of the Eastern Shore section 

 are especially suited to their needs. 



The beaver feeds on a wide range of plants. These may be sedges, 

 rushes, water grasses, various roots and tubers, and bark, leaves, and 

 twigs of bushes and trees. In winter it feeds primarily on green 

 branches that it stores under water near the lodge. In Maryland its 

 favorite trees appear to be sweetgum, pine, ash, dogwood, oak, and 

 maple. 



These animals are monogamous, and it is believed that they mate 

 for life. Breeding begins about mid- January and extends to the end of 

 February. The gestation period is approximately 120 days, and a 

 single litter of from one to eight kits is produced a year (the most 

 frequent number being four or five). 



The beaver's most important activity is felling trees for dams and 

 lodges. A large beaver lodge is about 5 to 6 feet high and 15 or 20 feet 

 wide at the water level. More often, however, smaller lodges are built, 

 some 3 to 4 feet in height and 8 to 10 feet in diameter". The inside of 

 a lodge consists of one room about 2 to 3 feet in height, and as many 

 as 8 to 10 beaver may occupy it. The opening to the lodge is always 

 under water. Many beavers, however, that inliabit lakes or deep 

 streams live in bank dens rather than constructing lodges and dams. 



The beaver is active throughout the year, but is seldom active during 

 daylight hours. Its routine workday begins at dusk and ends at dawn. 



