Family SCIURIDAE 131 



MARMOTA MONAX (Linnaeus) 

 Woodchuck Groundhog 



Description. — The woodchuck, fig. 75, is a stout-bodied, 

 squirrel-like mammal with short, powerful legs, short ears, 

 short blunt muzzle, and relatively short furry tail. In most 

 individuals the upper parts are a grizzled yellowish gray to 

 dark brown; the under parts are lighter, often with a reddish 

 wash. The feet are dark brown or black. Occasional wood- 

 chucks are almost black. The four toes of each front foot and 

 the five toes of each hind foot have well-developed claws. 



Length measurements: head and body \()\/^-\9]/2 inches 

 (415-495 mm.); tail M/^-6 inches (110-155 mm.); over-all 

 201/^-251/^ inches (525-650 mm.); hind foot 3-3M inches 

 (75-95 mm.). Weight: average about dYz pounds, that of the 

 male slightly greater than that of the female. 



The flat skull, fig. 73^, has well-developed postorbital proc- 

 esses and is 75-100 mm. (3-4 inches) long. The strong incisors 

 are cream colored or white. Dental formula: I 1/1, C 0/0, 

 Pm 2/1, M 3/3. 



Life History. — The woodchuck is normally an animal of the 

 forest edge. It prefers rolling land that is well drained, fig. 2. 

 In some parts of Illinois, the woodchuck lives along wooded 

 river bluffs, in other parts in more open country, and in a few 

 areas in heavy woods. In level countryside, it may make its 

 burrow in a railroad or highway embankment, fig. 5. 



As with most other squirrel-like animals, the woodchuck re- 

 stricts its activity to daylight hours. It digs innumerable bur- 

 rows, most of which at some time become the homes of other 

 mammals. At one of the enlarged entranceways to a burrow 

 it may be seen dozing in the warm sun, or busily trying to rid 

 itself of fleas, lice, or ticks, or sitting upright to get a good 

 view of its surroundings. It may occasionally climb a tree. 



The female is occupied during the summer months in rearing 

 a family. The nest chamber is in the burrow and so situated 

 as to remain dry. The nest itself consists of only a few leaves 

 or blades of grass. Two to six (usually three or four) young 

 per litter are born in April or May. The young, fig. 75, grow 

 and mature rapidly, and before long are busily feeding on green 

 plants. Both young and adults commonly feed on clover, alfalfa, 

 dandelions, wild lettuce, and plantain. 



