The Mammals of Warren Woods, Berrien County, Michigan / Occasional Paper of the Museum of Zoology, Number 86

by Lee R. Dice

The most widespread habitat of the cleared upland on the south part of the preserve is the blue-grass habitat. In this habitat the blue-grass, Poa, is the dominant plant, growing to a height of usually not over 0.5 meter. With the blue-grass are associated a few thistles, yarrow, and several other herbs. During the whole period of my stay in the region, July and August, the habitat was very dry, and the grass and herbs had mostly dried up. This habitat and all the other habitats of the clearing were being heavily pastured by stock.

Trap-lines totaling one hundred mouse traps, set on August 6 and August 18, took on the first nights two prairie white-footed mice, one house mouse, and one young thirteen-striped ground squirrel. More white-footed mice were taken on later nights. Many ground squirrels were taken in larger traps at the mouths of their burrows; most of these were young of the year, and all of them were very fat in preparation for their approaching hibernation.

Cultivated field habitat:

Scalopus aquaticus machrinus. Prairie mole. 1.

Peromyscus maniculatus bairdii. Prairie white-footed mouse. 23.

Microtus ochrogaster. Prairie vole. 1.

Mus musculus musculus. House mouse. 2.

Sylvilagus floridanus mearnsii. Mearns cottontail. 2.

Cultivated fields occur throughout the region about the woods, but the only ones in which trapping was done were wheat stubble-fields. After the wheat was cut off these stubble-fields grew up rather thickly to weeds. On the ground there were a number of fallen heads of wheat and some shelled-out grain, furnishing abundant food for mice.

Seventy mouse traps set in a wheat stubble-field just north of Warren Woods, caught on the first nights, August 13 and August 29, sixteen prairie white-footed mice. Other white-footed mice and two house mice were taken on later nights. Several cottontails were seen in this field, and a few mole ridges were noted. A prairie mole was taken by Clifford Reid in a grassy patch at the edge of a garden. In another wheat field the Helming boys picked up a prairie vole.