Chapter V: Introduction: Geographic Limitations (4)

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.

The life history of the beaver is one of the most interesting of all mammals. It has been studied for centuries by naturalists in both the New and Old Worlds, for the beaver, with but few differences, is native to both. All this study and observation notwithstanding, the habits are still only partially known. This is because the beaver is mainly a nocturnal creature which spends most of its daylight hours in the concealment of a lodge or burrow. Then, too, in the northern latitudes where the ponds are covered with ice throughout the long winters there is little opportunity to observe this phase of its existence. There is but one species of beaver in North America but about two dozen subspecies. The northern types and those which live in the mountains of the Southwest seem to be dam builders who live in beaver “lodges.” Those which inhabited rivers of the lower desert were mostly “bank” beavers which lived in burrows in the banks of streams. This latter type is rare today.

Perhaps the best way to understand the ecological importance of the beaver is through watching the rise and decline of a typical colony. Picture if you will a small, shallow stream flowing gently down a narrow valley in the mountains. Bordering the low banks is a thicket of alders. Back of them a thick growth of aspens extends to the edge of the valley and mingles with the spruce trees on the slope. Down this slope comes a young male beaver at a clumsy gallop, his broad tail striking the ground with an audible thump at every lope. This emigrant has struck out for himself because the colony to which he belongs has become crowded. He finds the stream and, since the water is too shallow to conceal him, crouches under an overhanging bank until darkness falls.

As soon as it becomes completely dark, he hunts for a suitable place to build a dam and soon finds a site to his liking. On one side of the stream a thick clump of alders projects from the bank, and on the other a water-soaked log is half buried in the bottom of the creek. From these anchor points, he begins his dam, building toward the middle from each side. The work calls for a great deal of the alder brush to be cut and sunk in the bed of the stream. There it is weighted down with rocks and mud until secure. Additional brush is brought and interwoven with the first; gradually the structure grows until in a few days it converts the stream into a quiet pool deep enough to hide the beaver, should an enemy appear. As the water rises it covers the bases of the alders, which begin to die in the pond.

The beaver next turns his attention to building a lodge. Selecting a point to one side of the current entering the pond, he begins as he did with the dam by sinking brush to the bottom and weighting it down with rocks. As he builds, he cleverly fashions several underwater entrances to the house that will be. When he has finished, the house projects several feet above the water, and the materials are so thoroughly interlaced and plastered that even the most determined enemy would despair of gaining entry to the living room. Debris from the construction has floated downstream to become lodged in and on the dam, making it more secure and watertight that it was when first built.

With the dam and the lodge both completed, the next task is to collect a food supply for the following winter. This is carried on intermittently during the autumn. It consists of cutting down aspens, whose bark the beaver dearly loves, sectioning the branches and small trunks into pieces which may be handled conveniently, and dragging them to the pond. Once in the water, they are weighted down and will remain in good condition for a long time. The beaver is joined in this task by a female which has also migrated from an overcrowded colony. Two need more food than one, consequently their trails begin to head a little farther into the aspen forest as they work through the crisp autumn nights. These trails converge as they leave the forest and approach the pond, and end in a few well-developed mud slides that enter the water. Constant traffic of the wet beavers leaving the water keeps the slides moist and slippery.

As winter settles in on the mountains, a thin skim of ice begins to form on the edges of the quiet water on cold nights. Then one night it freezes completely over. This causes the beavers no inconvenience at all because if on one of their underwater excursions they should wish to surface for air, they have but to swim to a shallow place with firm bottom, and with one quick lift of their powerful muscles break a hole through the ice with their backs. They can break surprisingly thick ice in this way. The beavers live in comfort and plenty throughout the winter. The living room of the lodge has been furnished with comfortable beds of the cattails that have already become established along the edge of the pond. The lodge, although tightly built, still admits enough air for the beavers and food is stored in plenty on the bottom of the pond. As the bark is gnawed from the aspen branches, the bare poles are added to the bulk of the house or used in further construction of the dam. Before long, the mild southwestern winter merges into spring.

In late spring the beaver family is considerably increased by the arrival of four miniature beavers. They weigh but 1 pound each at birth and are fully furred. At this time, the father is ostracized and the mother and her young live together in the lodge. When the young are about 3 weeks old, they take to the water for the first time. They quickly learn the beaver method of swimming; this is to kick with the hind feet and let the forelegs trail loosely alongside the breast, using the flat tail both as elevator and rudder. The young beavers are called kits, and indeed are as playful as true kittens can be. It is most amazing to watch them cavorting about in the water with as much ease as youngsters of other mammals do on dry land. As autumn nears, this play is exchanged for the sterner duties of existence, and the young take their places as adults of the family.

Fifty years pass. As the colony increases the dam must be made larger, new lodges must be built; and when the trails to the aspen forest become too long, canals are dug part way out to lessen the hazards which may befall the beaver on dry land. The pond gradually silts up to higher and higher levels until at last it is full of black, fertile soil. All of the aspens within reach are finally cut down and the hungry beavers turn to the resinous bark of the spruces. Finally the struggle is given up. The beavers migrate to a new location, and the following spring a freshet tears out the center of the dam. Now the pond is gone. With it are gone the trout that played in its depths, and the teal that rested there on their way south. In its place is a beaver meadow, a grassy park in the center of the spruce forest with spring flowers spangling its green surface. Aspens are already beginning to crowd in about its edges, and the creek is cutting deeper into its soft soil with every spring. Before long heavy erosion will begin to take its toll, and some day in the future a male beaver will again come galloping awkwardly down the slope.

The changing conditions which such a cycle bring about are almost impossible to evaluate. At least three climax types of environment are represented: those of the alder thicket, the beaver pond, and the beaver meadow. In a graphic fashion this cycle illustrates what is going on in Nature continually, more slowly perhaps, but just as surely.

Porcupine
_Erethizon dorsatum_ (Greek: to irritate in allusion to the quills and
Latin: pertaining to the back)

Range: Most of North America north of the Mexican border. Notable by their exception are the south central and southeastern United States.

Habitat: Usually associated with conifer forest, yet may sometimes be found miles from any forest. An inhabitant of all life zones up to timberline (Arctic-Alpine).

Description: A black to grizzled black and yellow creature covered with quills. Total length 18 to 22 inches. Tail 7 to 9 inches. Weight 10 to 28 pounds. Body short and wide; supported by short bowed legs. Tail heavy and muscular, armed with short slender quills. Head small with dull eyes and long black whiskers, but with short ears. The incisors are extremely large and are of a bright, rich yellow color. The quills are shortest on the face and reach their greatest length near the middle of the back. Often they are nearly hidden in the coarse, seal brown to black underfur. The long guard hairs are also seal brown close to the body, but change to a rather sere yellow at the tips. Only one young is brought forth each year in a den among the rocks, or sometimes in a hollow log. The young are among the most precocious of any mammal.

The porcupine in North America is considered as belonging to but the one species _dorsatum_, although there are seven subspecies. The most common subspecies found in the Southwest is _epixanthum_ (Greek _epi_, upon, and _xanthus_, yellow), sometimes called “yellow-haired” porcupine. The porcupine is unique among North American mammals in bearing the sharp quills which are perhaps its most interesting feature. Certainly they are responsible in large part for the unusual life history of this misunderstood animal.

Quills are no more than greatly modified hairs, and in sorting through the various types of pelage on a porcupine’s back, a few examples will be found which are intermediate between the hair and the quills. This does not mean that coarser hairs gradually turn to quills. Each follicle produces hair or quill, as the case may be, for the life of the animal. A quill consists of three well-defined parts: a solid sharp tip usually black in color; a hollow shaft, which is white; and a root similar to that of a hair.

The sharp tip is smooth for a fraction of an inch, but from this point on, it is covered with a great number of closely appressed barbs. These can be felt by rubbing the quill the “wrong” way between thumb and forefinger. It has been found that these barbs flare away from the surface, when the quill is immersed in warm water. It seems natural that they would do the same when embedded in warm, moist flesh. At any rate, quills are always difficult to extract, and if left in the victim they penetrate ever more deeply until they may pierce some vital organ and cause death. In other cases, they have been known to work entirely through body or limb and emerge on the opposite side. This is due to muscular action of the victim, some movements tending to force the point farther, the barbs at the same time effectively preventing any retreat.

Below the barbs the tip of the quill flares to join the shaft. Pure white and opaque, this portion is used by Indians to form decorative bands of quill work on the fronts of buckskin vests and jackets. This part is also hollow, and before removal of a quill from the flesh is attempted, a little of the end should be cut off. This collapses the shaft and makes extraction somewhat more easy, but very little less painful. Actually there is little excuse for a human to become involved with one of these mild-tempered creatures, but sometimes dogs are badly hurt in encounters with them.

The root is the portion by which the quill is attached to the body. Although it is a common belief that the porcupine can “throw” its quills, the truth is that the root portion is extremely weak and the quills are easily withdrawn from the body when the barbed tip is driven into an enemy. In fact, any violent movement of the animal may dislodge quills, even though nothing has touched them. There are several well-authenticated accounts of quills having been flipped for several feet in this way, but in each case, it was entirely accidental and through no conscious effort of the porcupine. In other words, the armament of this slow, awkward creature should be considered strictly defensive in every respect.

Like the skunk, which can also defend itself most effectively, the porcupine has little apparent fear of its enemies. When threatened with violence it simply brings its head down between the forelegs and turns its rump toward the attacker. With hair and quills erect it resembles a soft furry ball. Appearances are seldom more deceiving! The guard hairs half conceal a spot on the back where a whorl of long quills radiates out in a large “cowlick.” Should any enemy touch these long guard hairs, the muscular tail is thrashed vigorously about in an effort to drive the somewhat shorter but equally keen-pointed tail quills into the attacker. With every attempt at attack from another angle, the porcupine turns so as to present its rump to the enemy. There is one Achilles heel, however, in this otherwise almost perfect defense. It is the unprotected underparts, which at times of danger are always kept pressed against the ground or against a tree trunk. A few carnivores, among them the mountain lion and the fisher, are known to kill the porcupine by flipping it over on its back and tearing it open. Even these large predators seldom escape unscathed, however, and both lions and fishers are known to have died from the effects of quills accidentally taken into the digestive tract.

To those who have heard that porcupines live only on bark and always girdle the host trees, it may come as a surprise to find that this is only partly true. Although “bark” is eaten to some extent throughout the year, it is seldom the main diet. When a great deal is taken from one tree, it is gnawed off in an aimless pattern which may or may not girdle the tree. During the spring and summer, a porcupine becomes a browser on tender leaves and twigs in the undergrowth. In autumn and winter, it feeds more on mistletoe and pine needles than on bark. With its low reproduction rate, there is little danger of it eating up our forests, unless its natural enemies are removed.

Northern pocket gopher
_Thomomys talpoides_ (Greek: thomos, a heap and mys, mouse. Latin:
talpa, a mole)

Range: From northwestern United States and southwestern Canada to as far south as northern Arizona and northwestern New Mexico.

Habitat: Soft loam in the open places in the high mountains. Seldom found below 8,000 feet, but up to elevations of over 13,000 feet in New Mexico.

Description: The characteristic mounds of earth built up by this group of burrowing rodents are usually the best indication of their presence. The northern pocket gopher is of medium size. Total length 6½ to 9½ inches. Tail 1¾ to 3 inches. It is usually gray in color with darker patches behind the rounded ears. Eyes and ears are small. The short tail has a bare, blunt tip. Front claws are long and curved. The entire body is well muscled and gives an impression of power. Average number of young thought to be about four. At the high elevations at which this species lives, the young are not seen until rather late in summer.

The northern pocket gopher is one of the hardiest rodents on the North American Continent. Even so, it would not be able to survive the climate of the inhospitable regions it sometimes inhabits were it not for the fact that is spends almost all its life underground. This creature does not hibernate, but continues busily at the task of searching out food when most other subterranean dwellers are curled up fast asleep in their cozy nests. Why the gopher should continue working, while its ground squirrel cousins sleep, is hard to say. It would seem that it has the same opportunities to lay on fat for a winter’s rest. The chief reason seems to be that the bulbs and roots upon which it feeds are always available so long as the gopher keeps extending its underground workings. On the other hand, the ground squirrels, which gather their food aboveground, are cut off from this supply as soon as cold weather drives them to shelter.

The pocket gophers are much alike. There are three genera and a considerable number of species represented in the Southwest but, except for variations due to climate and terrain, their habits are similar. Burrows usually are constructed in deep loam or alluvial soils. These tunnels seem to follow an aimless pattern. Their course is marked by mounds of earth thrown out of the workings at irregular intervals. When the gopher is engaged in throwing out this excavated earth, the entrance to the tunnel is left open until the job is completed, then tightly plugged to prevent enemies from entering. The tunnels themselves are rather small in diameter, considering the size of the gopher, for if it wishes to retrace its steps and there is no gallery near at hand in which to turn around, it can run backward almost as easily as forward. There are usually numerous rooms excavated along the course of the tunnels. In one is a warm nest constructed of grass and fibers. Others are utilized for storage rooms and at least one is reserved as a toilet, thereby keeping the rest of the workings sanitary. When the ground is covered with snow the northern pocket gopher especially is quite likely to extend its activities aboveground. Here it builds its tunnels through the snow and often packs them tightly with earth brought up from below. This remains as earth casts, when the snow melts and forms a characteristic mark of its presence.

Chief foods of pocket gophers are the bulbs, tubers, and fibrous roots encountered in the course of their diggings. Whenever an especially abundant supply is found, the surplus is stored away as insurance against the time when future excavation produces nothing. Gophers also eat leaves and stems whenever available. Some plants are pulled down through the roof of the tunnel by the roots, and some are gathered near its mouth, although these trips “outside” are fraught with danger. Coyotes, foxes, and bobcats all are willing to chance an encounter with this doughty little scrapper for the sake of the tasty meal he will furnish.

Little is known of gopher family life. For the most part, they are solitary individuals, avoiding others of their kind. At breeding time, however, they may travel some distance across country to find a mate. These trips usually are carried out under cover of darkness. The young average four in number. They are born late in the spring and do not leave to make their own homes until early autumn.

Physically the gopher exhibits a striking adaptation to its way of life. The fur is thick and warm. It keeps soil particles from working into the skin at the same time it protects the wearer from the chill of his underground workings. The heavy, curved front claws are admirable digging tools. In especially hard soil, the large strong incisors are also pressed into service for this purpose. To remove the dirt from the tunnel, the gopher becomes an animal bulldozer. The front legs are employed as a blade pushing the soil, while the powerful hind legs push the body and load towards the nearest tunnel opening. The pockets from which this creature gets its common name are never used for hauling earth. They are hair-lined pouches located in each cheek and utilized for carrying food to the storerooms. There they are emptied by placing the forefeet behind them and pushing forward. Last, by virtue of its location, but certainly not least in usefulness, is the short, almost hairless tail. It is used as a tactile organ to feel out the way when the gopher runs backwards through the tunnels. In some respects, it is of more use than the eyes although the gopher uses these too, as can be attested by the quickness with which it detects any movement near the mouth of its tunnel.

The gopher’s place in Nature seems to be akin to that of the earthworm. By turning over the soil, the gopher enables it to more readily absorb water and air. At the same time, fertility is increased by the addition of buried plants and animal matter. This is indeed a fair exchange for the plants it destroys in its quest for food.

CARNIVORES
_Including the Insectivores and Chiropterans_

This group is distinguished from other animals by having canine teeth in both jaws. The function of these teeth is to catch and hold other animals, for carnivores are the predators. This is the most highly developed branch of the animal world and reaches a peak of specialization in man who, while lacking some of the physical qualifications of the other predators, has developed a brain which has enabled him to gain and keep ascendancy over all other animals. Considered with the group in this book are two other orders, the Insectivora and the Chiroptera. These orders embrace the mammals in North America that live principally on worms or insects rather than on other mammals. They are the shrews and bats, respectively.

Since carnivores are the hunters rather than the hunted, they enjoy far greater mobility than, for instance, the rodents. It is not necessary that they have a burrow in which to escape the attacks of other animals, for it is unusual for them to prey upon each other. Most of the predators remain in one area only from choice or, in the case of adult females, in order to rear the young. Few of them hibernate; bears and skunks do spend a considerable time during the cold weather in a torpor, but it is an uneasy sleep at best, as anyone who has disturbed these animals at this time can attest. As far as the Chiroptera are concerned, some species of bats hibernate and others migrate to a warmer climate to spend the winter. Since most of the predators are active all winter, while many of the rodents are in hibernation, this can be a period of famine for carnivores. At the same time, it is a season of increased danger for those species which are still active and upon which these predators prey.

Because these hunters are continually stalking other animals, their habitats are as varied as those of their quarries. Thus, the mountain lion is a creature of the rimrock, where he can most conveniently find deer browsing on mountain-mahogany; while his smaller cousin, the bobcat, stalks smaller animals in the slope chaparral. The wild dogs hunt plains and brushy country for ground squirrels and rabbits. In the weasel family we find the marten in the treetops pursuing squirrels, the weasel hunting mice in the meadow, and mink and otter pursuing prey near to or in the water, Some species, such as the bears, are omnivorous and may be encountered almost anywhere that a plentiful supply of food of any kind can be found. Practically all of the species, excepting bats and skunks, can be considered diurnal as well as nocturnal, but the majority are most active during the hours between dusk and sunrise.

Since the carnivores’ purpose in Nature’s scheme is to control the vegetable eaters, it follows that each predator must be somewhat superior, either physically or mentally, or both, to the species upon which it preys. The associations between pursuer and pursued may be casual with species such as the coyote, which preys on a great number of smaller species, or they may be sharply defined as with the lynx, which in certain localities depends almost entirely upon the snowshoe hare for food. The apparent ferocity with which some predators will kill, not only enough for a meal, but much more than they need, cannot as yet be explained. This habit is most pronounced in the weasel family. It may be that more than ordinary control is called for in the case of their host species, rodents in most cases. Whatever the reason, this wanton killing has not upset the balance which these species maintain. Man, the most ruthless and intelligent predator of all, is the only species which has been successful in exterminating others.

The predators hold a favored place in the esteem of most naturalists. At first, sympathy for the weak and indignation against the strong are perfectly natural human feelings. As the necessity for control and the wonderful way in which Nature attains a balance becomes apparent, the role of the predator becomes more and more appreciated by the student.

Mountain lion
_Felis concolor_ (Latin: a cat of the same color; referring no doubt to
the smooth blending of the body coloration)

Range: At present, mostly confined to the western United States and Canada, and all of Mexico south to the southern tip of South America. There are a number of mountain lions in Florida, and persistent reports indicate that they may be making a comeback in a number of other Eastern States.

Habitat: As the range indicates, habitats vary widely. Mountain lions in the Southwest show a preference for rimrock country in the Transition Life Zone or higher, but they are often seen in all the life zones.

Description: A huge, tawny cat with long, heavy tail. The long tail is a field mark identifying the young, which, having a spotted coat, otherwise resemble young bobcats to some degree. Total length 72 to 90 inches. Tail 30 to 36 inches. Weight 80 to 200 pounds. Color may vary from tawny gray to brownish red over most of the body, the underparts being lighter. The head and ears appear small in proportion to the lean muscular body. The teeth are large, the canines being especially massive. Like most members of the cat family, the mountain lion has large feet with long, sharp claws. The tracks show the imprint of four toes together with a large pad in the center of the foot. The young may be born at any time of the year. Only one litter is born every 2 to 3 years, and the average number of young is three.

Probably no species of mammal in the New World equals the mountain lion in farflung distribution. From the Yukon to Patagonia, this elusive carnivore can still be found in considerable numbers in spite of aggressive campaigns against it. In the United States, it is the chief representative of the wild cats, a group noted for fierce and predacious habits. Fortunate indeed is the person who sees one of these great felines in the wild. This may not be as difficult as one might imagine because mountain lions often travel through comparatively well settled areas. It is especially possible in the Southwest, for the four-State area covered by this book contains the heaviest population of mountain lions in the United States. However, the comparative abundance of this carnivore has not resulted in a better understanding of it. The mountain lion is still one of the least known and most maligned creatures of our times.

The Mexicans know this cosmopolite as “leon.” In Brazil it is called “onca.” Perhaps the most distinguished name, and rating as the first in New World history, is “puma,” given it by the Incas. Early American settlers of the east coast called it “panther,” “painter,” and “catamount.” In the northwestern United States, it is known as “cougar” and in the Southwest, as mountain lion. Although there is but the one species _concolor_, there are a number of subspecies. About 15 are now recognized, most of them geographical races and not markedly different from the species. Four of these subspecies are found in the four States with which we are concerned. One of the most interesting is _hippolestes_ which inhabits the State of Colorado. Translated from the Greek this is “horse thief,” an appropriate epithet indeed for this ghostly marauder. As might be expected from their vast distribution, the several subspecies have a tremendous vertical range. In the Southwest they are found from near sea level in southwestern Arizona to the tops of the highest peaks in Colorado.

In the more than four centuries that have elapsed since the white man first set foot on soil of the New World, a great mass of folklore concerning the mountain lion has accumulated. Half fact, half fiction, these tales have been repeated from one generation to another and few details have been lost in the telling; indeed, in most cases, several have been added. Most common are those which describe its fierceness and its attacks on man. In the main, these tales are lurid and convincing, but they do not stand up under scientific scrutiny. It is true that such attacks have occurred; one of the most recent and best verified was that on a 13-year old boy in Okanogan County, Washington, in 1924. It resulted in the death and partial devouring of the unfortunate youngster. Yet sensational as this incident was, it resulted in publicity far out of proportion to its importance. In fact, articles concerning this case are still appearing at intervals. The truth of the matter is that very few authentic cases of mountain lion attacks upon humans have ever occurred in the United States, and that most of these _could_ have been caused by the mountain lion’s being rabid. Certainly such attacks are not typical behavior of the normal animal. As far as man is concerned, the lion will take flight whenever possible, and even when cornered it is not nearly so pugnacious as its little cousin, the bobcat.