Number 109February 25, 1922
By L. R. Dice and H. B. Sherman
The authors of this paper spent the summer of 1920 inwestern Michigan studying the mammals of the region forthe Michigan Geological and Biological Survey. From June25 to August 4 was spent in the Cisco Lake Region withheadquarters on Lindsley Lake; August 6 to August 20 acamp was maintained in the woods four miles southeast ofLittle Girl's Point; and from August 20 to September 6 wasspent working from a camp on the western shore of LakeGogebic, about three miles south of Lake Gogebic Station.The first two camps were in Gogebic County, the third inOntonagon County.
The field work was performed jointly by the two authors,under the direction of the senior author, who is responsiblefor the identification of the species, the descriptions of thegeneral areas and of the habitats, and is jointly concerned in[Pg 2]writing the annotated list.
In addition to our own records, we have secured many valuablenotes on the distribution of the larger species from J.E. Fischer, of Merriweather, Ontonagon County, a trapperof many years' experience; and from Benjamin J. Twombley,of Bent's Resort, Wisconsin, who has made many observationson the mammals of the Cisco Lake Region. We have alsoadded a number of records from J. E. Marshall, who trappedfor many years, beginning 1884, in Ontonagon and Gogebiccounties, and from Ole Petersen, at one time a trapper atGogebic Lake.
The habitats in which records of occurrence have beenobtained for the region under consideration are listed undereach species; and the number of individuals taken, or seen andpositively identified, in each habitat are given. From thefigures a rough estimate of the relative abundance of thevarious species in the different habitats can be obtained, butthe various habitats were not trapped or studied equally intensively,and for the larger and the rarer forms the numbersgive little dependable data on relative abundance.
Cisco Lake Region. In the Cisco Lake Region there aremany lakes, mostly small, but several of a length of one tothree miles. The water-level in the Cisco Lake chain has beenraised six or ten feet by a dam across the outlet, and thischange in water-level has killed the trees along the lake borders,so that the lakes are fringed by a narrow line of deadtrees. The habitats of emerging vegetation and of aquaticvegetation have been much altered by the change in water-level,and these habitats cannot be well studied in these lakes.However, the neighboring lakes in which the water-level hasnot been changed show that the forests of the region originallycame down to the water's edge, and that there was little normal[Pg 3]development of marsh or swamp.
The ridges between the lakes rise in general to heights oftwenty-five feet or more, though bluffs are not formed. Theseridges are mostly covered by mixed hardwood forest in whichthe hard maple, yellow birch, hemlock, and linden are thedominant trees. There are numerous small wet depressions,some of them containing small black spruce bogs, while othersinclude a few arbor-vitae mixed with linden and ot