22 AN ECONOMIC STUD'S OF FIELD MTCE. 
Tlie bluegrass vole (M. j>. auricularis) , a form with ears overtop- 
ping the fur, which is dark and glossy, occurs in southern Indiana 
and in Kentucky, Tennessee, Mississippi, and Alabama. It has been 
taken in northeast Texas also, so that its range probably extends 
through southern Arkansas and connects the two areas. 
The woodland vole (J/, p. nemoralis) is the largest form of the 
pine vole in America, and has longer and less gloss} r fur than the 
forms east of the Mississippi. Its color is deep chestnut, darker 
than typical pinetorum, but lighter than xc<ilo/>.s<>/(l<<x or auricularis. 
It occurs in wooded parts of southern Iowa, eastern Nebraska and 
Kansas, and in Missouri, northern Oklahoma, and Indian Territory. 
Pine mice differ greatly in habits from the other species of Micro- 
tus. All the American representatives of the group have similar 
habits, and the injury they do to crops is little less in extent than that 
inflicted by meadow mice and prairie mice. 
DAMAGE BY FIELD MICE. 
While field mice of the various groups differ but little in the 
nature of their food, the circumstances under which they injure crops 
vary. Meadow mice invade cleanly cultivated fields only under the 
shelter of snow. Hence they do most damage in years of great snow- 
fall. Although prairie mice commit greater depredations under 
cover of snow than in open seasons, their attacks upon crops are far 
less dependent upon snowfall than those of meadow mice. Pine 
mice work in the shelter of their own burrows; hence their injuries 
to plants are quite independent of the amount of snow. 
DAMAGE TO MEADOAVS AND PASTURES. 
Complaints of damage to meadows and pastures by field mice have 
been increasing in recent years. Usually the injury is confined to 
small areas, which the animals attack from the shelter of snowdrifts 
or old grass. Under cover of these, the animals eat the succulent 
croAvns of clover and other grasses ; and when the snow lies for several 
weeks the crops over large areas are often completely ruined. Some- 
times whole fields of red clover are so badly damaged by mice that 
they have to be replowed in the spring and planted to other crops. 
Damage to permanent, or unculth 7 ated, meadow 7 s is usually more 
serious, as the mice breed and multiply throughout the field and, 
under cover of the growing crop of leafy stubble, devour and destroy 
throughout the year. Occasionally, however, actual benefit may re- 
sult from their thinning the grasses and stirring the soil about the 
roots. Thus, after the vole plague in Scotland in 1892, the farmers 
reported that the pastures were better than before ; but the improve- 
ment by no means compensated for the losses caused by the impaired 
pasturage of the two preceding years. 
