APRIL, 1902. LIST WITH NOTES OF THE MAMMALS OF DODGE CO., WIS. 1 17 
These Mice gather in considerable numbers under shocks of 
grain standing in the fields, but aside from occasionally cutting the 
bands of bundles they do little or no harm. 
Pcromyscus Icucopiis (White-footed or Wood Mouse). 
Our White-footed Mouse of the leucopus group may, by sub- 
sequent study, prove to be the sub-species uoveboracensis. 
This species occurs sparingly with us in the ratio of 50 bairdi 
to one leucopus. 
Though generally considered more of a woodland species than 
bairdi, yet I have taken them in traps in grassy fields a mile from 
any timber. 
Ahis decumanns (Brown or Norway Rat). 
Common about barns, in basement cellars, under grain stacks, 
in fields during the summer, about stone walls — anywhere that 
food can be found and sufiicient cover to their taste. 
In September, 1899^ one was seen running along the beach at 
Fox Lake, fully a mile from any building. 
Mils mtisculns (House Mouse). 
Abundant, about buildings and in the fields, often taken in 
small traps set for V oles, Wood Mice and Shrews. 
Microtus pennsylvanicns (Common Meadow Vole). 
Beyond all question the most abundant mammal of Dodge 
County, even outnumbering the Common Mouse and Brown Rat. 
They may be found in pastures, fields, meadows, marshes, both 
dry and flooded, along fences — practically everywhere except in 
woodland. Some years they are exceedingly abundant in a given 
field, and the next season, under precisely similar circumstances 
not one can be found there. My only explanation for this is that 
they may perform slight migrations, from one location to an- 
other. One season a certain clover field contained hundreds of 
them, the next season the clover crop was even heavier than the 
previous year, but not one could be found. 
This species brings forth two and perhaps three litters per year, 
varying from 5 to 9 young, in number, though on but one occa- 
sion have I observed the latter number. A farmer once reported 
a nest of 12 young, six of which were one-half the size of the 
other six. In this instance it is fair to presume that two females 
occupied the same nest as their home. 
