Hanson.-SmaU Mammal Censuses 
 
 
    Descriptions of the pelage of these six specimens are given 
below: 
Individual 
(Collector's 
Number) 
   638 Entirely white except for brown hairs on the distal half of tail.

   652 Entire back and sides brown; ventral portion of the body white, the

       white extending slightly higher on the head and neck region and 
       present on the dorsol side of the toes of the fore legs. 
   686 Pelage entirely white including the tip of the tail. 
   651 Pelage midway between the white of winter and the brown of sum- 
       mer. The brown limited to the dorsal % of the body and extending 
       down the dorsal sides of the fore and hind legs and tail. A white

       patch above the nose and extending around the eyes as a circumor-

       bital ring; a larger white patch in front of each ear. Ears brown,

       slightly tipped with white. Sides of neck white and numerous white

       hairs intermixed with the brown of the back where it joins the white

       sides. 
   653 Similar to No. 652. 
     1 Similar to No. 652. 
Harvest Mouse-Reithrodontomys megalotis pectoralis* Hanson 
    A local reconnaissance was made on the Sauk prairie, in addi- 
tion to the censuses in Columbia County, to gather further in- 
formation regarding the habitat preferences of the harvest 
mouse. One of the cover types trapped in Sauk County was a 
tall stand of ragweed in a sandy fallow field. On entering this 
field two harvest mice were observed running about. One of 
these mice was captured by hand, while subsequent trapping 
yielded an additional three. As no other species of mice were 
caught in that field, it would appear that the harvest mice like a 
partial over-head canopy and a relatively herb-free, hard-packed 
ground surface that permits freedom of movement. Their ap- 
parent preference for the cultivated counterpart of this eco- 
logical niche, alfalfa fields, is evident from Table XV. They were 
also more abundant in this habitat relative to the total popula- 
tion than in any of the other cover types. 
    This mouse is fairly common about Prairie du Sac. Hence, 
it is surprising that specimens had not been reported from Wis- 
consin prior to 1941. Errington (1932) and Errington, Hamer- 
strom, and Hamerstrom (1940) did not report it in owl pellets 
collected from the Prairie du Sac region. This species was, how- 
ever, frequently recorded in owl pellets that they studied from 
    A paper by the author relating to the discovery of this species in Wisconsin
and its dis- 
tribution and taxonomy has been published by the Chicago Museum of Natural
History. See 
Literature Cited. 
 
 
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