Number 109February 25, 1922

OCCASIONAL PAPERS OF THE MUSEUM OF ZOOLOGY

UNIVERSITY OF MICHIGAN

NOTES ON THE MAMMALS OF GOGEBIC AND
ONTONAGON COUNTIES, MICHIGAN, 1920

By L. R. Dice and H. B. Sherman

The authors of this paper spent the summer of 1920 in western Michigan studying the mammals of the region for the Michigan Geological and Biological Survey. From June 25 to August 4 was spent in the Cisco Lake Region with headquarters on Lindsley Lake; August 6 to August 20 a camp was maintained in the woods four miles southeast of Little Girl's Point; and from August 20 to September 6 was spent working from a camp on the western shore of Lake Gogebic, about three miles south of Lake Gogebic Station. The first two camps were in Gogebic County, the third in Ontonagon County.

The field work was performed jointly by the two authors, under the direction of the senior author, who is responsible for the identification of the species, the descriptions of the general areas and of the habitats, and is jointly concerned in writing the annotated list.

In addition to our own records, we have secured many valuable notes on the distribution of the larger species from J. E. Fischer, of Merriweather, Ontonagon County, a trapper of many years' experience; and from Benjamin J. Twombley, of Bent's Resort, Wisconsin, who has made many observations on the mammals of the Cisco Lake Region. We have also added a number of records from J. E. Marshall, who trapped for many years, beginning 1884, in Ontonagon and Gogebic counties, and from Ole Petersen, at one time a trapper at Gogebic Lake.

The habitats in which records of occurrence have been obtained for the region under consideration are listed under each species; and the number of individuals taken, or seen and positively identified, in each habitat are given. From the figures a rough estimate of the relative abundance of the various species in the different habitats can be obtained, but the various habitats were not trapped or studied equally intensively, and for the larger and the rarer forms the numbers give little dependable data on relative abundance.

Descriptions of the Regions Studied

Cisco Lake Region. In the Cisco Lake Region there are many lakes, mostly small, but several of a length of one to three miles. The water-level in the Cisco Lake chain has been raised six or ten feet by a dam across the outlet, and this change in water-level has killed the trees along the lake borders, so that the lakes are fringed by a narrow line of dead trees. The habitats of emerging vegetation and of aquatic vegetation 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 has not been changed show that the forests of the region originally came down to the water's edge, and that there was little normal development of marsh or swamp.

The ridges between the lakes rise in general to heights of twenty-five feet or more, though bluffs are not formed. These ridges are mostly covered by mixed hardwood forest in which the hard maple, yellow birch, hemlock, and linden are the dominant trees. There are numerous small wet depressions, some of them containing small black spruce bogs, while others include a few arbor-vitae mixed with linden and other typical trees of the wet hardwood forest. Small areas of nearly pure hemlock occur on some slopes near the lake shores. A few large tamarack bogs are present.

Though the pines formerly occurring have been taken out, the region otherwise is in nearly its native condition. A few former clearings along the lake shores have grown up to brush or to white birch saplings or small trees.

Little Girl's Point Region. Much of the region in the near vicinity of Little Girl's Point has been cleared or burned, but a few miles to the east and southeast there are still considerable areas of native forest. The high ridge running through the region bears a splendid forest of maple, yellow birch, and linden, with little if any hemlock. However, on the steeper lower slopes hemlock occurs in nearly a pure stand. At one place was found a nice grove of large white pines, mixed, on the lower edge of the slope, with a few hemlocks. Black spruce-tamarack bogs are extensive and arbor-vitae swamps occur commonly. The extensive burned areas south of the point have grown up to a thicket of aspen, birch, and various shrubs and saplings. A few small areas are under cultivation.

Region at the north end of Gogebic Lake. Most of the region about the north end of Gogebic Lake is low and wet. A number of small black ash swamps occur near the lake, and further back there are extensive black spruce bogs. The main forest is of a much mixed wet hardwood type, sugar maple, linden, yellow birch, elm, and hemlock, being the dominant species. The forest in most places reaches the edge of the lake, though a few sandy beaches occur. However, the level of the water in the lake has been raised a few feet by a dam across the outlet, and beaches were probably more abundant before this occurred. The lake is so large, about 13 miles long by 1 to 2 miles broad, that wave action is quite pronounced.

One beaver meadow was studied, this meadow including areas of grasses and of sedges, traversed by ditches, small mud-flats covered with low rushes, and alder thickets.

Just north of Lake Gogebic Station there are some high hills having bluffs on the southern exposures. These hills were visited, but they had been extensively logged and burned over and no attempt was made to trap for mammals on them.

Some large burned areas have grown up to sapling forests of aspens. Near the towns of Lake Gogebic and Merriweather nearly all the forests have been cleared away, but farther south on the sides of the lake the woods are still in their natural condition.

Habitats

The habitats studied in Gogebic and Ontonagon counties may be listed as follows:

Exposed shores:
Open-water
Beach
Dirt-bluff
Forest—shore

Protected shores:
Water lily
Pondweed
Rush
Submerged-sedge
Cat-tail
Willow-thicket
Mud-flat

Meadow:
Ditch-border
Tall-sedge
Grassy-meadow
Alder-thicket

Swamps:
Black ash swamp
Arbor-vitae swamp

Bogs:
Leather leaf bog
Sphagnum bog
Black spruce—tamarack bog

Forests:
Hemlock forest
White pine forest
Wet hardwood forest
Dry hardwood forest

Mountains:
Rock-bluff
Mountain-heath