g been pastured. It is thus a splendid place for the study of the
native faunal conditions.

Although the whole area in the preserve is small there are other areas
of adjoining forest along the Galien River, so that, for the smaller
mammals at least, the results of the study and trapping should
indicate the primitive habitat distribution. The relative abundance of
the different species, however, is probably much changed by the
decrease throughout the whole region of the carnivores, which have
been much hunted and trapped by man.

The mammals of Warren Woods were intensively studied by the author
from July 3 to September 3 in the summer of 1919. A camp was
maintained near the edge of the Woods, and by trapping and hunting
every effort was made to determine the mammal fauna of the preserve.
From one hundred to two hundred traps for small mammals and about
twenty traps for the larger species were kept constantly in operation.
A small amount of trapping was done in the fields and along the
roadsides immediately adjoining the Woods and a few records were
secured from the camp house.

The work was supported by the Michigan Geological and Biological Survey.
Dr. Alexander G. Ruthven directed the work and gave much assistance in
securing the needed collecting equipment. Much help was given by George
R. Fox, Director of the Warren Foundation, not only in getting to and
from the camp at the Woods and in numerous other courtesies, but also in
information about the Woods and about the mammals there. The plant
identifications were made by Mr. C. Billington.

The figures following the specific names in the lists of mammals from
each habitat indicate the number of individuals trapped, shot, or seen
and positively identified in that habitat.

NATURAL HABITATS

_Aquatic habitat_:

_Mustela vison mink._ Mink. Reported.

_Fiber zibethicus zibethicus._ Muskrat. Reported.

Mink and muskrat are reported by residents to occur in the Galien
River in and near Warren Woods, but I was unable to secure any
specimens though traps were set for them; neither did I see any signs
of their presence.

_Buttonbush-swamp habitat_:

_Peromyscus leucopus noveboracensis._ Northern white-footed
mouse. 8.

_Mus musculus musculus._ House mouse. 2.

A large buttonbush swamp occurs in the preserve just south of the
Galien River, but around this the native trees have been cut away and
over its accessible edges it