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 Air: Aerial Burns and clearings: Herbaceous stage Shrub stage Paper birch—aspen stage Young hardwood forest stage Artificial conditions: Overflow swamp Cultivated-field Edificarian

This list of habitats is admittedly not complete for the regions visited, but is intended to include those which we studied. We had no opportunity of studying either the shores of a large river or jack pine ridges, both of which situations will undoubtedly have habitats not here recognized.

The habitats studied in Gogebic and Ontonagon counties but every habitat has been listed which seems to form a distinct type of mammal environment. We are firmly convinced that it is better to describe a great number of habitats rather than to lump different kinds of environments together. It is infinitely easier for a later worker to combine several habitats, which have been split too finely, than it is to separate the component habitats which may have been lumped together under one name.

No attempt is made to give complete lists of the plants found in each habitat, but only the more conspicuous plants or those of special importance to the mammals are mentioned. The plant names used are mostly taken from Darlington's list of Gogebic County plants.[1]

Exposed Shores

Open-water habitat: This habitat includes the areas of open water with no rooted vegetation in the deeper parts of the lakes and rivers. On Lake Superior at Little Girl's Point this habitat comes directly to the beach, for the wave action on this exposed point is sufficient to prevent the growth of plants along the shore. In Gogebic Lake and in the smaller lakes of the Cisco Lake Region there are also many parts where there is no rooted vegetation along shore. This habitat, therefore, covers by far the larger part of the aquatic conditions of northwestern Michigan. We secured no records of mammals for this habitat, and, though some aquatic species must occasionally occur in the open water along lake shores, they are rare there, and are practically absent from the areas of open water farther out in the lakes.

Beach habitat: The shore of Lake Superior at Little Girl's Point is subjected to heavy pounding by the lake waves, leading to the formation of a well-developed beach. To the east of the point the beach for some distance is five to ten yards wide, mostly of small gravel, with sand on the upper part; it ends abruptly against a steep dirt bluff. On the beach no vegetation grows and only a few scattered drift logs occur. To the west of Little Girl's Point undetached masses of solid rock are more prominent, though small patches of gravel occur in partially protected places. The beach here in general is narrow and rises steeply, so that the different beach zones, lower, middle, and upper, are not well marked. On the shores of Lake Gogebic are a few small sand beaches; but around this lake, as well as around the smaller lakes of the region, the forest comes, in general, directly to the edge of the water. There was no opportunity to trap for mammals on a beach, and no records for the habitat were obtained.

Dirt-bluff habitat: To the east of Little Girl's Point the beach of Lake Superior runs along the base of a dirt bluff about 35 feet high. The storm waves of winter evidently wash against this bluff, eroding it away and destroying the forest, which is of the hemlock type, growing on the level above. The bluff is quite steep, and along with small exposures of bare clay bears a number of scattered herbs and a few shrubs and small trees, such as alder, willow, arbor-vitae, yellow birch, paper birch, and red maple. No collecting was done in this habitat and no records of mammals were obtained from it.

Forest—shore habitat: Along all the lakes of the region, except Lake Superior, the forests in general come down to the water's edge. The marginal forests are frequently dominated by hemlock, though often a wet hardwood forest occurs along the shores, and in a number of places along Gogebic Lake black ash swamps border the water. Red maple (Acer rubrum) and mountain ash (Sorbus americana) frequently occur along the exposed shores of Gogebic Lake. Frequently young forests of paper birch or quaking aspen have replaced the original forests in the clearings and burned areas along the lake borders. The shore beside a forest commonly rises abruptly a few inches to a foot or more in a firm bank, and in most cases the trees overhang the water to some extent. These shores are the favorite promenade of the porcupine; and the mink, muskrat, and otter are typical of the habitat.

Protected Shores

Water lily habitat: In shallow, protected parts of the lakes and channels of the Cisco Lake chain there are extensive growths of white and yellow water lilies (Castalia tuberosa and Nymphaea advena). Water lilies also occur in many places as a narrow border at the edge of deep water. Muskrats were the only mammals noted in this habitat, but mink and otter probably occur also.

Pondweed habitat: A thick growth of pondweeds (Potamogeton spp.) occurs in protected places along the shores in many parts of the lakes of the Cisco Lake chain. Muskrats were noted in this habitat. In Gogebic Lake the exposure to wave action is in most places too great for a good development of pondweeds, though in the northern end of the lake there are a number of widely scattered plants of this type, but not forming a very well marked habitat.

Rush habitat: On somewhat protected shoals, both in the lakes of the Cisco Lake Region and in Gogebic Lake, there is sometimes a growth of rushes (Juncus sp.). Along the lower course of the Merriweather River, just before it enters Gogebic Lake, rushes thickly cover numerous small areas. The plants in both cases grow partly submerged in the water. No records for mammals were obtained from this type of habitat, though doubtless some of the amphibious forms frequently occur here.

Submerged-sedge habitat: Sedges in general do not occur as a definite belt about the margins of the lakes in the region studied. The only place where any considerable growth of sedges was noted at the edge of the water was along the lower course of Merriweather River, just before it enters Gogebic Lake. Here there are considerable areas of sedges partially submerged by the water. No records of mammals were obtained from this habitat.

Cat-tail habitat: Under native conditions cat-tails (Typha latifolia) apparently do not often form extensive habitats in the region. Along the marshy borders of the lower Merriweather River at Gogebic Lake a few small patches were seen. Small patches were seen in other places along railroad tracks where embankments had produced small areas of marshy ground.

In the Cisco Lake Region a few of the areas of timber killed by the raising of the water-level have grown up to cat-tail swamps. In these swamps there are many standing dead trees and fallen logs as well as some areas of open water. The cat-tails seem to occur mostly in those swamps having only a small connection with the main body of the lake. In these places the cat-tail is dominant, though numerous sedges occur, and there is some sphagnum growing on the fallen logs and along the shore. A few small black spruces are starting. Along the edge of such a swamp a few deer-mice were taken, but these were evidently stragglers from the adjacent forest.

Willow-thicket habitat: Willows do not occur commonly along the water margins of the lakes of the region. The only place, except in clearings, where willows were noted as a definite growth is along the lower course of the Merriweather River at Gogebic Lake. Along this part of the river there are extensive growths of shrubby willows, growing (in early September) in a foot or more of water. The indications were that earlier in the summer the water about these plants must have been at least a foot higher. Signs of muskrat were noted at the edge of these willows.

Mud-flat habitat: Around the margin of a pond formed by an old deserted beaver dam near Gogebic Lake, two miles southwest of Merriweather, is a narrow strip of mud, very wet and sparsely covered with a growth of low rushes. The strip of muddy ground varies from about 1 to 4 meters in width and extends a short distance up along the edge of the small ditch draining into the pond. At the upper border of the strip of muddy shore is a thick growth of sedges, meeting the muddy shore at a fairly sharp line.

In this habitat meadow mice are common and four jumping mice (Zapus hudsonius) were taken.

Meadows

Ditch-border habitat: A number of small ditches run through an old beaver meadow of considerable size near Gogebic Lake, about two miles southwest of Merriweather. The borders of the ditches are muddy and the banks are from 6 to 18 inches high; in places the ditch borders are closely encroached upon by the tall sedges of the adjacent meadow. A small amount of water was present (in early September) in most of the ditches. In mouse traps set at the edges of these ditches, partly in the water, star-nosed moles and navigator shrews were taken. In a larger trap a skunk was taken.

Tall-sedge habitat: In the beaver meadow studied near Gogebic Lake, an area about 200 meters by 100 meters or more is occupied by a heavy growth of high, coarse sedges, reaching a height of about .75 to 1.00 meter. A few grasses and some low herbs occur sparingly among the sedges. The habitat had not been burned over and the ground is covered with a thick mat of the decaying leaves and stems of the sedges and grasses. In most places the ground is quite wet, sometimes soggy to walk upon, and in a few places low hummocks are numerous. A similar habitat was found in rather a narrow strip at the edge of Mud Lake, one-fourth mile southwest of Thousand Island Lake, Gogebic County. Here a small area of meadow occurs along the inlet of a tiny stream. This area apparently had been artificially cleared of its forest, but the level of the lake had not been raised.

The habitat differs from the submerged-sedge habitat of protected lake shores in being higher above the water and in not being covered with water from July to September; probably water does not stand to any depth on it at any time. The Richardson shrew is apparently a characteristic mammal of this habitat, though other shrews and mice were taken here also.

Grassy-meadow habitat: Part of the beaver meadow studied near Gogebic Lake is covered by a thick growth of grasses and sedges of a number of species. The ground of the habitat was rather dry and had been burned over the previous year. Grasses are also dominant over a few small areas near Mud Lake in Gogebic County. On a small area of the clearing near this lake a thick stand of bluegrass (Poa) is almost the only plant present. This occurs on an area of fairly moist mud. On the drier slope near the forest Poa also is abundant, forming the dominant species over a strip about 5 to 10 meters wide. Jumping mice are common in this habitat.

Alder-thicket habitat: On very wet ground just below an old beaver dam near Gogebic Lake there is a heavy growth of alder (Alnus incana) about 20 feet high. No other shrubs were noted in the thicket. The ground under the alders is mostly bare, there being only a few ferns, grasses, and other herbs. On the ground are many dead sticks fallen from the alders. This situation contained few mammals, only one Blarina being taken in four days' trapping with 25 traps. At the south end of the beaver meadow willows and alders are invading the sedges in very wet ground. No trapping was done in this situation.

Swamps

Black ash swamp habitat: A number of black ash swamps occur along the shores of Gogebic Lake, being apparently partially flooded during periods of heavy rains and during stages of high water. In a swamp of this type near the north end of Gogebic Lake on the west side, black ash (Fraxinus nigra) is the dominant tree, the trunks reaching diameters up to 2 feet. Elms (Ulmus americana) sometimes reaching a trunk diameter of 3 feet are common, and yellow birches and hard maples are common also. Black maples are rare, and lindens are few. The trees are high and the forest crown nearly closed. Underbrush is common in the more open places, this being mostly mountain maple (Acer spicatum) with a few young firs, young arbor-vitae, and Virginia creepers (Parthenocissus quinquefolia). There are numerous ferns, and herbs are abundant. Under the more closed parts of the forest canopy the ground is mostly bare, underbrush and herbs being scanty. Smaller black ash swamps occur in the Cisco Lake Region, and in the vicinity of Little Girl's Point a number of small black ashes were noted in a swamp of mixed arbor-vitae and black spruce.

Arbor-vitae swamp habitat: In the Cisco Lake Region arbor-vitae (Thuja occidentalis) occurs commonly near the edges of the lakes and in the wet depressions in the forest. Near Gogebic Lake also the arbor-vitae grows commonly near the shores of the lake and in wet places in the woods, especially at the edges of swamps. But the trees in both these areas, so far as seen, were small, and the arbor-vitae did not form a dominant species, but occurred in a small percentage mixed with the other types of forest. However, in part of the region near Gogebic Lake extensive arbor-vitae swamps are reported to occur. In the vicinity of Little Girl's Point arbor-vitae swamps are common, occupying the wet lower northern slopes of the high ridge.

In a swamp of this type three miles southeast of the point arbor-vitae is the dominant tree, reaching trunk diameters of two feet and more. Under the dense shade of the high forest crown there are many young trees of the same species, and the forest has evidently reached a temporary climax. Of other trees, a few small yellow birch, a few young firs and hemlocks, and one fallen white spruce (Picea canadensis) were noted. The ground is very wet and there are numerous tiny streams, which frequently disappear under the ground. Fallen trees and decaying logs on the ground make a thick tangle, very difficult to penetrate. The underbrush is scanty; mountain maple is rather common, and there are a few young black ashes. Much moss grows on the ground and on the decaying logs.

In a depression two miles south of Little Girl's Point is a mixed growth of arbor-vitae, black spruce, with a few black ashes. The trees are mostly small, none of them exceeding about eight inches in trunk diameter. In August the ground was very wet, there being standing water in some places, and the ground was heavily covered with sphagnum. This situation may be considered transitional between the black spruce bog and the arbor-vitae swamp. No traps for mammals were set in this situation.

Bogs

Leather leaf bog habitat: In the northwestern corner of Fish-hawk Lake and at several places along the channel connecting Lindsley and Cisco lakes a heavy growth of leather leaf (Chamaedaphne calyculata) adjoins and overhangs the water, a considerable portion of the growth actually floating on the water. With the leather leaf is associated much sweet gale (Myrica gale) and alders, and these plants form almost the entire mat in some of the wetter areas. At other places sphagnum becomes abundant and the conditions approach those of a sphagnum bog. Other plants commonly found in the leather leaf bog in the Cisco Lake Region are the Labrador tea (Ledum groenlandicum), swamp laurel (Kalmia potifolia), wild rosemary (Andromeda glaucophylla), small cranberry (Oxycoccus oxycoccus), pitcher-plant (Sarracenia purpurea), and small trees of black spruce and tamarack. In a typical leather leaf bog on the Ontonagon River near the outlet from Thousand Island Lake a large beaver house is located.

Sphagnum bog habitat: In a restricted sense the name is here applied to the part of a bog which is free from trees. It differs from the leather leaf bog in having a greater amount of sphagnum, for while the leather leaf bog when first developed over the water has little or no sphagnum, the sphagnum bog, as here considered, is almost entirely covered by sphagnum. The shrubs found in the two situations are apparently identical, except that the leather leaf is less abundant. A small bog of this type borders the edge of Mud Lake in the Cisco Lake Region, and small parts of many bogs are free from trees. So far as was determined, the mammal fauna is the same as that for the black spruce—tamarack bog, from which the only difference is the absence of trees.

Black Spruce—Tamarack Bog habitat: The dominant bog tree in this region is the black spruce (Picea mariana), which is usually small and stunted. With the black spruces are a lesser number of small tamaracks (Larix larcina), which in places may be dominant. The ground is heavily covered with sphagnum, which is normally soaked with water. Shrubs are abundant, though usually not forming a closed mat. Of the shrubs the leather leaf is the most abundant, though Kalmia, Andromeda, Ledum, and blueberries are common. A few young white pines and red maples were noted. Sedges occur frequently, and the pitcher plant is very characteristic.

Forests

Hemlock forest habitat: In the Cisco Lake Region groves of hemlock (Tsuga canadensis) frequently occupy the lower parts of steep slopes adjoining the lakes. One such area studied is made up of practically a pure stand of hemlocks, the trunks being from about 6 to 18 inches in diameter. A few very old yellow birches are present, and also a few young sugar maples and arbor-vitae, the latter chiefly near the water's edge. Shrubs and herbs are nearly absent, and the forest floor is covered by a thick carpet of dead needles. There are many decaying logs, usually covered by a thin coat of moss. In the Little Girl's Point Region nearly pure stands of large hemlocks cover many of the lower parts of steep slopes and also occur commonly on well-drained soil elsewhere. In the vicinity of the north end of Gogebic Lake a few small groves of hemlocks were noted, but the ground in general is so low and swampy that the species mostly occurs as a part of the mixed forest of the region. Animals are rare in the habitat.

White pine forest habitat: White pine (Pinus strobus), which formerly was a common forest tree in northern Michigan, has now been mostly removed for lumber. Near Little Girl's Point a small natural grove of this species was studied, occupying a moderate southerly slope above a black spruce bog. The area is about 50 by 150 meters in size. White pines are by far the most numerous and dominant tree, the trunks measuring up to about five feet in diameter. In the grove yellow birch, some of large size, are common; toward the bottom of the slope hemlocks are also common; and near the edge of the bog there are a few arbor-vitae. Shrubs are almost absent, there being merely a few small seedlings of arbor-vitae, hemlock, and fir, mostly toward the bottom of the slope. A few scattered clumps of grass appear, but the forest floor is mostly covered only by a thick carpet of dry pine needles. Numerous dead limbs and sticks have fallen from the pines.

Wet hardwood forest habitat: The land adjoining much of Gogebic Lake is low and poorly drained. Here is found a mixed forest dominated by sugar maple (Acer saccharum), black maple, hemlock, yellow birch (Betula lutea), linden, elm (Ulmus americana), ash (not black ash), and ironwood (Ostrya virginiana). The hardwoods are decidedly dominant over the conifers. The forest crown is high and closed, and the trees are large. The underbrush in general is scanty, though in some places there is a thick growth of mountain maple (Acer spicatum) and of sugar maple seedlings. Leatherwood (Dirca palustris), hazel, ferns, and a few young firs (Abies balsamea) also occur.

Some of the lower forests in the Cisco Lake Region approach the wet hardwood forest type, though none are extensive in area, and they are usually surrounded and dominated by the dry forest condition.

Dry hardwood forest habitat: The highest development of the dry hardwood type of forest was found on the upper parts of the moderately high ridge near Little Girl's Point. The slopes in general are very gentle, but well drained. The forest here is dominated by the sugar maple (Acer saccharum), yellow birch (Betula lutea), and linden (Tilia americana). Hemlocks are rare, and only one elm was seen. The trees are large, the trunks frequently reaching diameters of two feet or more. The forest crown is high and heavy. Underbrush is scanty and low, being mostly young seedlings of sugar maple, though seedlings of linden are numerous. Other shrubs and herbs noted were the leatherwood (Dirca palustris), hazel (Corylus rostrata), yew (Taxus canadensis), gooseberry, ferns, false Solomon's seal, and grass. On the ground are many decaying leaves, these usually forming a heavy carpet; decaying logs and freshly fallen sticks are common.

In the Cisco Lake Region the drainage is not so good as in the vicinity of Little Girl's Point, and the forests of that district are of a type somewhat intermediate between the wet hardwood forest and the dry hardwood forest. In the Cisco Lake Region the topography is much broken, there being many small hills and ridges, and many small depressions, often poorly drained. In the damp depressions, if not wet enough for a bog, arbor-vitae and hemlock are common, while on the ridges sugar maple and linden are characteristic, though hemlock occurs here sparingly also. There is accordingly much local variation in tree forms, but the whole forest is decidedly of a hardwood type.

The dry hardwood forests of the Little Girl's Point Region are inhabited by many deer-mice, while only a few of this species are found in the wet hardwood forests near Gogebic Lake, bob-tailed shrews being there the most abundant mammal and red-backed voles being common, both of which are rare in the other districts. In the dry hardwood forest near Little Girl's Point four woodland jumping mice (Napaeozapus) were taken, while in the Cisco Lake Region only two were taken in a period twice as long, and at Gogebic Lake none were secured. These observations indicate that moisture conditions in hardwood forests have an important influence on the mammal fauna.

Mountains

Rock-bluff habitat: Rock exposures are rare in the region studied. However there are several high hills with steep exposures of rock a short distance north of Ironwood and Bessemer. These hills could not be studied in the time available, and the only cliff examined was on a small range of hills northeast of the station of Lake Gogebic. On one of these hills is a nearly perpendicular rock cliff about 200 feet high and facing to the southward. The small talus slope at the bottom is overgrown with shrubs and trees, and on the small ledges and gullies of the face of the cliff a few small trees, shrubs, and herbs are also growing. The most conspicuous plants of the rock habitat are scrub oaks, aspens, and heaths. No trapping was done in the habitat, and no notes on mammals were secured. Probably the mammal fauna is not very large.

Mountain-heath habitat: A narrow, poorly developed belt of heath fringes the upper edge of the rock cliff examined north of Lake Gogebic. Characteristic plants are the blueberry and bearberry, mixed with creeping juniper and a few scattered grasses. The habitat is very narrow and is closely encroached upon by shrubs and trees, such as sumac, cherry, white pine, jack pine, oaks, aspens, and paper birch. Signs of fox were noted at the edge of the cliff, but no trapping was carried on here.

Air

Aerial habitat: The only aerial mammals are the bats, of which four species were taken during the summer. The flying squirrel is not considered to be a true aerial form.

Burns and Clearings

Fires have been numerous throughout northern Michigan and a large part of the region is covered by various stages in the succession following fires or clearings. The areas studied were selected as representative of the natural conditions of the peninsula, but even in these districts there are many burned areas.

Many large areas have been heavily logged over, sometimes followed by fire, with a result similar to that of a fire. In the region studied there are numerous small clearings, some of which are in use as the residences of settlers, but most have been allowed to revert to a wild condition. The stages in succession on an abandoned clearing seem to be similar to those following a fire, and they are here considered together.

Herbaceous stage: After a fire in a forest in this region the first vegetation to spring up seems to be the herbs, of which the fireweed (Chamaenerion angustifolium) is most prominent. A number of areas dominated by this type of vegetation were seen, but the type seems to be short-lived, and is probably quickly replaced by shrubs and tree seedlings. The stages in succession following a fire in swampy areas may be somewhat different from that in a hardwood region, but no data was obtained. No opportunity presented itself to study the mammals of the herbaceous stage, and I have no records for the species found there.

Shrub stage: Following a fire or clearing in a hardwood area the herbaceous stage is apparently quickly followed by a thick growth of shrubs and young trees. The characters of the shrub growth vary considerably with the texture of the soil, amount of soil moisture, slope, and completeness of burning. The growth is usually quite thick, though in some clearings where the growth has been kept down for some time there may be open grassy patches. In small clearings near Fish-hawk Lake the raspberry (Rubus strigosus) is a characteristic species, but near Little Girl's Point it is much less common. A large area of shrub studied near Little Girl's Point is on a rather steep slope facing to the north, though part is at the bottom of the hill on a very gentle slope. There are no large trees, but saplings up to 2-1/2-inch trunks occur; most, however, are smaller. The quaking and large-toothed aspens (Populus tremuloides and P. grandidentata), paper and yellow birches (Betula papyrifera and B. lutea), sugar maple, and linden are common seedlings. Shrubs, such as the sumac (Rhus hirta), wild cherry (Prunus pennsylvanica), raspberry, willows (Salix spp.), mountain maple, red-berried elder (Sambucus racemosa), and hazel are common. A few herbs, like the fireweed, golden-rod, and pearly everlasting, occur in open places.

A number of mammals are found in the shrub stage, but they are far less abundant than in mature hardwood forest.

Paper birch—aspen stage: The continued growth of the young trees in the shrub stage leads to the production of a sapling forest of the more quickly growing species, the paper birches and aspens. Often one or other of these species becomes dominant to the practical exclusion of the other, but sometimes both occur together. On the slopes near the lakes of the Cisco Lake chain aspens are rare, and the sapling forests on the clearings and burns are almost a pure stand of paper birch. Near Watersmeet, however, the aspen seems to be the dominant form, and few paper birches were seen. Near Gogebic Lake, also, the quaking aspen is the dominant form, though paper birches are common in the sapling forests. The growth in these sapling forests is very thick, and the ground is nearly bare of vegetation, though it is heavily covered with dead sticks and small logs. In a thick growth of quaking aspens, on wet ground studied near Gogebic Lake, a number of alders and paper birches, a few young trees of sugar maple and arbor-vitae, and a rare elm occur. A scanty undergrowth of mountain maple and numerous sugar maple seedlings is present. Few mammals are found in this stage of the forest.

On the western slope of Birch Point on Cisco Lake there is a good stand of paper birches, growing in an open stand with much grass in the spaces between the trees. This place has been much used for camping and it may be that the development of the grass is the result of opening the forest by clearing out some of the trees. Among the birches are numerous young firs and white pines, with a few young sugar maples, and a rare arbor-vitae. The birches show many signs of age, and would evidently, if undisturbed, soon give way to a forest dominated by the pines and firs. In the grass among these trees deer-mice, red-backed voles, and jumping mice (Zapus) were taken. Signs of snowshoe hare were seen.

Young hardwood forest stage: On the eastern slope of a low ridge at Birch Point, Cisco Lake, a young hardwood forest is rapidly replacing a former growth of paper birches which has followed a fire. In this growth numerous old paper birches still persist, but they are being strongly crowded by a thick growth of vigorous young sugar maples, some of which have trunk diameters up to about eight inches, and which form a dense shade. Among the maples are numerous young firs and a few young hemlocks and arbor-vitae. The ground is mostly bare, being scantily covered by leaves. The soil is moist, but there is no grass and little brush. In this habitat deer-mice were taken, and one red squirrel was seen.

Artificial Conditions

Overflow swamp habitat: Due to the rise in water-level of the lakes of the Cisco Lake chain many low areas of forest have been flooded and killed. Many of the dead trunks of these trees still remain standing, mixed with fallen and decaying logs in the water. Locally these habitats are called "overflow swamps," a name here adopted for the habitat. There is little living vegetation in these swamps, an occasional water lily being almost the only plant present. Porcupines commonly walk out on the logs of the swamp to secure the water lily leaves, and probably the mink occasionally runs over the logs in its movements along the waterways.

Cultivated-field habitat: Cleared fields occur only sparingly in the regions visited, and these fields are small in size. No study of their inhabitants was made, though silver-haired bats were collected while they were flying over a small clearing in the Little Girl's Point Region.

Edificarian habitat: Towns and buildings are not very common in northern Michigan. In and around a cabin on Lindsley Lake a number of deer-mice were trapped, and signs that porcupines had invaded the cabin were noted.