The porcupine is another rodent that is 

 unique in its habits. It stores body fat in its 

 heavy, quill-covered tail, but does not hi- 

 bernate. The quills, which are barbed and 

 can be painful to an attacker, form its chief 

 protection, although it can also climb 

 trees, using its long, sharp claws. Its food 

 is the bark of many different trees and 

 shrubs, including aspens, willows, and 

 conifers. 



Montana Department of Fish. Wildlife & Parks 



Beaver 



Beavers have some special characteris- 

 tics. These thick-furred, broad-tailed ani- 

 mals live and work along slow-moving 

 waterways, making dams when they can, 

 and building bankside burrows when the 

 river or stream is too wide or flows too fast. 

 When they have dammed a stream, they 

 build a large house of twigs and branches, 

 with an upper chamber and an underwater 

 entry tunnel. They then store branches of 

 aspen, willow, and cottonwood by sinking 

 them and weighting them down with larger 

 branches. 



The beavers' teeth continue to grow 

 throughout their lives, remaining sharp 

 enough to cut down large trees. They have 

 an exceptionally strong jaw, also, which 

 enables them to fell trees in a few minutes. 

 They usually have two young, called kits, 

 who stay with the family until they are 2 

 years old. 



The broad tail of the beaver comes in 

 handy for many uses— a slap of the tail on 

 the water produces a sound of warning; it 

 also can support this 30- to 40-pound ani- 

 mal as the beaver cuts its way through tree 

 trunks. It stores fat, too, to provide body 

 energy during the winter. 



Muskrats (Ondatra zibethicus] inhabit 

 much the same territory as beavers do, but 

 prefer the quieter waters of marshes 

 rather than rivers. They build a similar 

 sort of house, using cattails and reeds in- 

 stead of branches. Although they like 

 marshes or shallow water for their homes, 

 they will build bank burrows on water- 

 ways. Their food consists of reeds and 

 other water vegetation. Irrigation ditches 

 occasionally provide them with a home; it 

 is not unusual to see them living close to 

 human habitations. 



Squirrels: Family Sciuridae 



The large squirrel family includes tree 

 squirrels, flying squirrels, chipmunks, 

 marmots, prairie dogs, and ground squir- 

 rels. Some members of this family have 

 adapted to living in trees, and some are 

 burrowers; a variety of habitats suit them. 



The red squirrel lives in Montana's 

 spruce-fir and lodgepole pine forests. It 

 caches stores of pine nuts in holes beneath 

 the trees where it nests. The flying squirrel 

 is found throughout western Montana, but 

 is rarely seen because of its nocturnal 

 habits. It glides between trees, and is not 

 really capable of flight. 



Several kinds of chipmunks live in west- 

 ern Montana, among them the least chip- 

 munk, and the northwestern or yellow pine 

 chipmunk. The red-tailed chipmunk oc- 

 curs in western Montana, and the Uinta 

 chipmunk has a limited range in the Bear- 

 tooth Mountains. These speedy little ani- 

 mals can be seen foraging at campsites, or 

 in the woods with their cheek pouches 

 stuffed full of pine nuts. Both squirrels and 

 chipmunks store winter food, but do not hi- 

 bernate. 



Hibernation is a dormant (or sleep- 

 ing) period for animals such as the 

 marmot that burrow below the 

 frost line — above this "line" the 

 ground will be frozen; below it the 

 soil will stay unfrozen. The ani- 

 mal's temperature may drop close 

 to the ground temperature at that 

 depth, so it requires less body heat 

 to live. Its breathing and heartbeat 

 slow down, too. The animal literally 

 uses up its stored fat to maintain 

 life during hibernation, and is thin- 

 ner when spring comes. 



