Part 8

Description: This woodrat will be recognized at once by its bushy, squirrel-like tail. The several other species in the same range have the usual scanty growth on the tail, so thin as to be almost unnoticeable. This species is large for a woodrat; total length ranges from 12½ to 18 inches. Tail 5½ to 8 inches. The soft, thick fur shows wide variation in color, as might be expected from the great range occupied by this species with its many subspecies. In general it varies from ashy to cinnamon above, to pure white on the underparts. Although the head has the same general shape as that of other woodrats, its appearance is altered somewhat by long, silky whiskers up to 4 inches in length, and extremely large ears. The dark, beady eyes, however, are typical of the genus. The young, from two to six, are born in early summer. This average of four or possibly less, when the breeding habits of all the subspecies are taken into consideration, seems low when compared with other small rodents. The low death rate indicated probably is due not only to this species’ secretive habits but to a high order of native intelligence as well.

Many are the names applied to this interesting little animal. “Mountain rat,” “pack rat,” “trade rat,” and woodrat are some of the most common. Several stem from the supposition that when the animal takes an article that suits its fancy, it always replaces it with something which it supposes to be of equal value. Observation of the creature’s habits will indicate that these “trades” are entirely by chance. These animals are continually carrying small objects about and often drop one in favor of another more to their liking. The fact is that the most attractive items usually are carried to the vicinity of the nest, and so the scientific name of one of the subspecies is perhaps one of the most appropriate for this industrious collector. This subspecific title is _orolestes_, which translated from the Greek means _oros_, mountain, and _lestes_, robber.

The penchant for carrying away another’s property leads to many incidents both comic and tragic. The rats are not at all averse to sharing a prospector’s cabin, and during hours when the rightful owner is away at work raise havoc with his possessions. During long winter nights they are no less industrious, and the mysterious sounds of their activities will keep even a sound sleeper awake for hours. Eventually this becomes so exasperating that drastic action is called for. One old prospector told me of a woodrat that had been bothering him for a long time. Traps proved of no avail and finally one night he placed his forty-five on a box beside his bed, together with a candle and matches. During the night he was again awakened and quietly sat up and lighted the candle. There on one of his cupboard shelves was the dim form of the rat. Taking careful aim in the flickering candlelight, he pulled the trigger and hit the animal “dead center.” The heavy slug literally blew it apart. Unfortunately it happened to be sitting directly in front of a 5-pound can of coffee. One may assume that without either woodrat or coffee he slept soundly thereafter.

My own experiences with this species have been no less exasperating. When but a youth, my brother and I were quartered in an old bunkhouse one winter. We chose the smaller of the two rooms as being easier to keep warm, and after a thorough clean-up moved in. No rank novices, we wired our watches to a nail driven into the wall and hung our other valuables from a wire stretched across the room. In the morning our socks were missing! Thereafter matters were uneventful for a week. The woodrat would come up through a hole in the corner of the room as soon as the lights were out. All night long it would make trips through the connecting door into the adjoining room and carry away loads of cotton from an old mattress on the unused bed.

Came the week-end and the Saturday barn dance about 3 miles up the canyon. Fresh shirts and trousers donned, coats and vests were taken from the chair backs upon which they had been carefully hung. Behold! One vest front was completely chewed out and carried away, presumably for nesting material. This was the last straw; the creature must be done away with.

On the following night plans were laid with care. Two 5-gallon oil cans were placed in the doorway. This left a narrow passageway just wide enough to accommodate a small jump trap. A piece of newspaper was placed over the trap and the end of the chain wired to the head of the steel bedstead. A short time after the lights were put out, a scratching noise indicated that the animal had come in through the hole. All was quiet until its nose came into contact with one of the empty cans. Then snap! A series of squeaks and the rattle of the chain gave warning that the creature was climbing into bed. As it came in over the head, the wildly excited occupants left by the foot. When the light was struck the rat was sitting in the middle of the bed. A heavy boot soon dispatched it and a semblance of order again returned to the bunkhouse. Strange to say, no more woodrats came in for the remainder of the season.

Although such experiences are the rule when this rat has moved into a dwelling, it is a delightful creature in its native haunts. It is a rim rock dweller; that is, it likes best to build its nest far back in some deep crevice of a cliff. If such a location is not available it may find a protected site in a talus slope or even among the roots of a tree. Usually these natural fortresses are further reinforced by the addition of a pile of sticks and miscellaneous materials piled helter skelter over the nest. The nest itself is quite large, usually a foot or more in diameter, built of the softest and warmest materials at hand. Somewhere adjacent to the nest will be found one or more caches of food against the time when the snows are deep and famine stalks the land. As has been mentioned, the woodrat is usually associated with the pines of the Transition Life Zone and above, and pine nuts are one of its most popular items of food. Acorns, seeds, berries, stone fruits, and some vegetation round out its vegetable diet. It will also eat meat whenever available although, except for insects, shows little inclination to kill its own. With such a varied menu, it seems entirely proper to call this rodent omnivorous.

One of the most characteristic marks of the woodrat’s home is a strong, musky odor. This is not an indication of uncleanliness. The animal is most fastidious in its toilette but has this body odor in large measure. A study skin will retain a strong trace of it for many years. Whether it functions for an identification to others of the species is not known, but it could well serve this purpose.

Although classed as a nocturnal animal, the bushy-tailed woodrat is often active throughout the daylight hours. They are not gregarious creatures; yet, since suitable nesting sites may not be found in some areas, other more favored localities often will harbor considerable numbers of the animals. Overhanging ledges may shelter the piles of litter denoting a nest every few feet. In such cases, a well-worn trail will lead from one to the other. This is not an indication that a colony lives there in peace and harmony. These rats are truculent creatures among themselves, and if a stranger should venture into a nest mound, he is evicted with many indignant squeaks and a fearsome snapping of teeth. The interloper seems to know he is out of order and usually leaves the nest at once without more than a token show of resistance. In neutral territory such as a cabin, however, several woodrats may share the area quite peacefully, but to the great annoyance of the human occupant.

The variety of sounds produced by such a group is quite amazing. Added to the usual high-pitched squeaks and patter of running feet are the mysterious rustlings of paper and other objects being dragged about. A peculiar thumping sound indicates a gait which I have never seen but often heard at night. It must be somewhat like the leaping flight of a kangaroo rat, at least it indicates a swift succession of leaps across a flat surface such as a floor or roof. Perhaps the broad surface presented by the flat of the bushy tail is of assistance in this maneuver. Then, like most rodents, the woodrat will thump with its hind legs as an alarm signal. This is perhaps the most noticeable sound of all, for it marks the instant cessation of all activity for every member of its kind within hearing distance. The “ear-splitting silence” that follows this signal literally presses in on one in the darkness.

Muskrat _Ondatra zibethicus_ (French Canadian word from the Iroquois and Huron Indian word for muskrat. Latin: the odorous substance of the civet alluding to the musk secreted by the muskrat)

Range: Virtually all of North America north of the Mexican border. Muskrats are found from near sea level to as high as 10,000 feet above it.

Habitat: This large rodent can exist only near a permanent water supply which is deep enough to shelter it from its enemies. This may be a lake, a marsh, or a running stream.

Description: A large aquatic rodent whose long, flat tail undulates from side to side when it swims. Total length 18 to 25 inches. Tail 8 to 11 inches. Weight 2 to 4 pounds. The thick, dark brown fur of the upper body is overlaid with brown to black guard hairs. The legs are short but powerful. The front feet are small, but the hind feet are relatively large and partially webbed, with stiff hairs on the edges of the webs and along the sides of the toes. The long, black tail is flattened vertically. It is so scantily haired that it may be said to be naked, but is covered with small scales up to 2 millimeters in diameter. The head is quite similar to that of a vole. The ears are so short as to barely protrude through the fur, and the eyes are small. Average number of young thought to be six per litter. Several litters may be born each year.

The presence of muskrats in a shallow lake or marsh is not difficult to detect. This is their chosen habitat, and here in water about 1½ feet deep, they build their characteristic mounds of rushes and cat-tails. Here they may also be seen on quiet days swimming about and carrying on their normal activities. In much of the Southwest, however, such favorite habitats are few and far between and the muskrats must take their choice, if there be one, between the few permanent streams and irrigation canals. In these altered circumstances they react quite differently; they may often be present in considerable numbers without anyone being the wiser. The change in habits required by this different environment illustrates the great adaptability exhibited by many of our most common mammal species.

The most important requirement of a muskrat is a permanent body of water of a depth sufficient for it to dive into and escape from its enemies. Given this, it will at once set about constructing a home. In a lake or marsh, there is little or no current. In sheltered bays, where wave action is slight, the bottom often will be muddy. In the shallow water along the shore, water plants such as tules and cattails will become established. This is indeed muskrat heaven, for these and other aquatic plants are both their food and building materials. The most edible portions of the plants are the roots and the stem portions which are below the surface of the mud. When one of these choice tidbits has been cut free by the muskrat’s sharp teeth, it is carried to some favorite place to be eaten. This may be a mud bar well sheltered by overhanging vegetation from prying eyes, the end of a log projecting above the surface of the water, or perhaps the roof of the “house.” The discarded portion of the stem is buoyant and usually lodges among the remaining plants until needed for building purposes.

When the muskrat house is being built, a great quantity of this flotsam is piled up until the resultant mound may project as much as 3 feet above the water and be 5 or 6 feet in diameter. The nest is built above the waterline in this half-submerged “haystack.” Entrance to the living quarters is by a tunnel which usually starts through the mud a short distance from the base of the house, goes under the edge of the structure, then inclines upward to the nest. Only one entrance is necessary for even if some enemy should tear through the tangle of rushes deep enough to reach the nest, it would take so long that every inmate could easily escape by this submarine route. The house serves one more important purpose in the far north. When the ice lies thick over the marsh and seals this water world away from air, the muskrats can still take short forays under the ice for food and return again to free air, without which no mammal can exist.

Had the muskrat learned to build dams such as beavers construct, the species might very well be near extinction in the Southwest, since such structures would seriously interfere with irrigation. However, since they have accepted conditions as they are, the muskrats do very well for themselves in the shallow streams and irrigation ditches. In fact, their population under the adverse conditions of today is probably far above that of the days before the white man arrived on the scene. Do not assume from this statement that a whole new way of life has been opened up for the muskrat. There has always been a “bank” muskrat that lived in burrows in the stream banks. This fast-water addict has now taken full advantage of the artificial streams that are the forerunners of agriculture almost everywhere in the Southwest. The burrows built into the canal banks seem to be identical with those constructed under natural conditions.

The “bank” muskrat builds three types of shelters, each with a definite and necessary function. These might be called the feeding burrow, the shelter burrow, and the breeding burrow, respectively. The first two are simple in design and have few variations, but the breeding burrow may be extremely complex. If a choice is available, all burrows will be in a bank along the swiftest flow of water, as on the outside of a curve in the canal, for instance. This prevents the entrances from silting shut as they would in the more quiet reaches.

There are two types of feeding burrows. The first and more common consists of a cut made just above water level in the side of a vertical bank. If possible, it is behind a portiere of hanging grass or weeds, so as to be completely screened from view. This is merely a safe place to which the muskrat can take its food and eat without being bothered by enemies. The second type of feeding burrow is more elaborate, consisting of several such chambers along the bank connected by short tunnels. These seem to be community shelters since they are used by several individuals at the same time. The added safety provided by the connecting tunnels seems to be the advantage in this type of dining room.

The shelter burrow not only affords escape from enemies, but may be a sleeping burrow as well. It consists of two tunnels which start at different levels under water and join just before they reach the main chamber, which of course, is above water level. The two tunnels assure an escape route if one or the other is invaded by an enemy. Each muskrat may have several of these shelter burrows. The one used as a sleeping burrow will be furnished with a soft nest of shredded leaves. Cattail leaves are a favorite material for this purpose. Wet, green cattail leaves in a damp underground cavern make a poor bed by most standards, but no doubt, it seems a dry, cozy retreat to the muskrat as it emerges dripping from its underwater tunnel.

The breeding burrows are large and elaborate in design. There is reason to believe they are not always the work of one individual. They may even represent combined efforts of several generations of muskrats. Often they are a labyrinth of tunnels connecting many nesting chambers, each with a nest of different age. This can be determined by the yellowing of the shredded leaves. As might be expected, there are usually a number of tunnels leading from this maze into the water. A half dozen of these underwater entrance tunnels is not unusual. All this room gives the young a place to exercise before they are able to take to the water.

Young muskrats are surprisingly precocious. They are able to leave the nest when very small, and at 4 weeks of age are weaned and capable of taking care of themselves, although only about one-fourth grown. At this stage, they are peculiar looking little individuals. The fur is still in the woolly stage, dark and bluish in color. The guard hairs have not yet appeared, and altogether they have an unkempt appearance. This rapidly disappears, however, when they leave the burrow. Their progress is so rapid that young born early in the spring are believed to breed during the following fall.

Though ordinarily confined to the immediate vicinity of water, muskrats sometimes are found in amazing places. The urge to travel sometimes influences them to go across country for many miles to some other body of water. They may also become overcrowded in an area so that food becomes scarce and some may leave on that account. It is not uncommon in the Middle West for them to burrow into a farmer’s root cellar in early fall and spend months in this haven of warmth and good food before they are discovered. Floods may carry them many miles away from established haunts and leave them stranded on high ground when the waters recede. A muskrat found in this predicament is not an animal with which to trifle. If it cannot escape by water, it will probably elect to make a stand. The long, sharp incisors are formidable weapons indeed, and any enemy, including man, had best allow judgment to become the better part of valor.

The tracks of muskrats are so characteristic that they cannot be mistaken for those of any other animal. Strangely enough they resemble to a striking degree those of certain types of extinct reptiles called dinosaurs. The tracks of the two small front feet are close together and overlapped somewhat by those of the larger hind feet. Between the tracks is the sinuous trail left by the sharp-edged tail.

Beaver _Castor canadensis_ (Latin: a beaver ... from Canada)

Range: The beaver, like the muskrat, can be found almost everywhere in North America north of the Mexican border.

Habitat: Near any water supply of enough volume, with or without damming, to provide security for a beaver family.

Description: The largest North American rodent; further distinguished by having a broad flat tail. Total length 34 to 40 inches. Tail 9 to 10 inches. Weight from 30 to 60 pounds. In color the beaver varies from a deep, rich brown in the northern states to a much paler shade in desert regions of the Southwest. The soft, rich underfur is partially concealed by coarse, rather stiff guard hairs. The brown color of the upper parts shades to a chestnut under the belly and on the inner sides of the legs. The forefeet are small with well developed claws. They appear naked but have a scanty cover of coarse hairs. The hind feet are large and webbed, and are similarly covered with a few coarse hairs.

The body of the beaver has somewhat the appearance of a kangaroo in that the rear portion is heavy and appear overdeveloped in comparison with the more stream-lined head and forequarters. Much of this impression is gained from the heavy, flat tail which is thick and muscular at the point where it joins the body. One of the most useful appendages possessed by any creature, the tail is paddled-shaped horizontally and about an inch thick in the middle, tapering to thin edges and tip. It appears naked, but is covered with scales.

The young, averaging four in number, are born in the late spring and, although they are soon able to take care of themselves, the family remains together for most of the year.

Indications of beavers in an area are their dams or the distinctive stumps left by their tree felling. Beaver tracks are seldom found. Although this aquatic animal often leaves the water, and may go a considerable distance overland, its tracks usually are obliterated by the passage of the heavy rump and the dragging tail.

The beaver, perhaps as much as any other factor, was instrumental in opening up western America to civilization. Even before the Thirteen Original Colonies had become firmly established along the eastern seaboard, venturesome men were working westward in search of more beaver to supply the ever-increasing demand for this soft-rich fur. Industrial empires were founded on this traffic in skins which came from as far west as the Mississippi River. By the early 1800’s, the trappers had penetrated to the Rocky Mountains, and in 1806, upon the return of the Lewis and Clark Expedition from the Pacific Northwest, they swarmed to the headwaters of the Missouri River system. Prior to this, the Southwest had been given little attention by the fur industry. It was considered an inhospitable region, inhabited by hostile Indians, and with a few settlements of Spanish colonists who, up to that time, had actively resisted the intrusions of the more aggressive Americans. However, by the year 1820, relations had improved to such a degree that a few of these hardy individuals were trapping on the headwaters of the desert rivers. Later, their activities spread to include the entire length of these remarkable watercourses.

These were the Mountain Men, a hard-as-nails breed of frontiersmen in a class by themselves. In the period from 1820-1854, when a large part of the Southwest became part of the United States through the Gadsden Purchase, they roamed the plains and mountains of the American Desert. Their roster includes such legendary figures as Bill Williams, Pauline Weaver, Kit Carson, and James Pattie. Their argosy was a quest for the rich, brown beaver pelts which were a golden fleece indeed when presented to the fur traders in far-off St. Louis. In time, their moccasined feet beat a broad path across the western plains—a path then known as the Santa Fe Trail, but identified today as U.S. 66, the “Main Street of America.”

Today, many of the streams which supported beaver colonies in the desert places have vanished entirely, and others have been so effectively harnessed for irrigation and power that there is no place for beavers in them. In the higher mountains, however, there are many streams remote from civilization where clear ponds still sparkle in the sunlight, and the splash and dripping of busy beavers can be heard on quiet, summer evenings. Because beavers quickly become established under any conditions which are at all favorable, they have been reintroduced into numerous places where they had been extinct for many years. Usually this is good conservation practice, but under some conditions, it may prove a mistake. Ecologically speaking, beavers probably are the most important creatures in any animal community of which they are members. This is because these busy engineers not only impose a tremendous drain on the surrounding area for material, very often they also radically alter the character of the terrain to fit their own needs.