mink
As might be suspected, such wildly fierce creatures make poor parents. The females sometimes desert the young while they are still too small to make their own way. Yet this, after all, is but a human criticism. Who is to condemn an animal which Nature has allowed to exist under conditions that would have eliminated a more amicable species?
Range: From northern Greenland south to northern United States with one extension south into Utah, Colorado, and New Mexico. To be expected in northern Arizona.
Habitat: Generally found in forests of the Transition Life Zone and higher. It will often be found in the Arctic Zone.
Description: A tiny predator with long body and short legs. Total length from 7 to 13 inches. Tail 2 to 4 inches. Weight 1½ to 3⅔ ounces. This wide range in statistics is from comparing the smallest females with the largest males. Males consistently average from one-fifth to one-fourth larger than females. Summer color is dark brown with white underparts and feet. There is a white line down the insides of the hind legs connecting the white of the feet with that of the belly. The tip of the tail is black. Winter coat is all white with the exception of the black tail tip. The body is long and supple, legs are short, the neck long and round. The head is small with rather large, bulging dark eyes. The ears are large for a creature of this size. Breeding dens are usually in the ground under large rocks or among the roots under a tree. Average number of young is thought to be about four.
I have a special affection for this tiny predator which, because of its fearlessness, has given me many a glimpse into its private life which would not have been possible in the case of a larger or more timid creature. Let no one underestimate the courage of this small mustelid which, if left alone, will continue its normal activities even under the close scrutiny of an observer, but if molested will often turn on its tormenter with a fury matched by few large animals. It shares these characteristics with two other relatives of the United States: the longtailed weasel (Mustela frenata), which is also found in the Southwest, and the least weasel (Mustela rixosa), which inhabits part of the northern United States, Canada, and Alaska. The short-tailed weasel will not be mistaken for either of the other species, since the least weasel has no black tip on the tail and the long-tailed weasel has a tail about one-third of its body length. The tail of the short-tailed weasel is only about one-fourth of its body length, and this species is considerably smaller than the long-tailed weasel.
Short-tailed weasels are the smallest carnivores in the Southwest. In fact, except for the least weasel, they are the smallest on the North American Continent. Despite its size, Mustela erminea is so hardy it ranges to the northernmost point of land in the Northern Hemisphere. This, the north coast of Greenland, is but a few degrees from the North Pole. The European form, not specifically distinct from ours, is equally hardy. It, too, inhabits not only the more temperate zones, but penetrates far north of the Arctic Circle wherever land is found. In our Southwest they are sometimes encountered at low elevations but more often in the higher mountains. Here they go through the winter change of color, but not so regularly nor so completely as in the far north.
The term “ermine” refers to this animal’s fur in the winter pelage. This is the royal ermine, reserved in days past for the use of the aristocracy. At its best this fur is a spotless white, except for the sharply contrasting black tail tip. In heraldry the pure white had symbolic significance, but to the weasel it has more mundane uses. These are as camouflage, both in pursuing prey and in avoiding attacks of enemies. In the far north this seasonal change of garb is mandatory and complete, but in the mild (by comparison) climate of our southwestern mountains the situation is somewhat altered. Here the creature can descend to lower elevations as winter comes on and, if it wishes, evade most of the severe weather. Under conditions which to some extent are left to its own choice, the degree of color change varies greatly. In snowy areas on higher peaks it will change to true ermine; lower down it probably will turn to a light yellow, and below snowline the animal will retain the same brown above and white below that it wears all summer.
short-tailed weasel
Like most other members of the weasel family, these small mustelids are admirably adapted to do their part in Nature. Their size permits them to enter the homes of all but the very smallest rodents. Their strength and suppleness combined with ferocity enables them to subdue animals several times as large. Surprisingly enough, though well able to climb, they do not eat many birds. Most of their prey is rodents. Small mice seem to be preferred, though chipmunks, ground squirrels, and woodrats also are taken. Pikas and small rabbits fall prey to these mighty mites, and there are many recorded cases of snakes being killed by them. Like the mink, short-tailed weasels will gather a cache of food when hunting is good. For their size they have a tremendous appetite; it has been estimated that one will eat half of its own weight in food every 24 hours. From this it will be seen that they can live only in an area where rodents are plentiful, and that they play a large part in keeping these creatures under control.
I have been privileged to see this weasel many times and under varying circumstances. In all of these encounters it has seemed evident that at first the animal accepts the intrusion of man not so much as an enemy, but rather as a competitor. Under these condition it will continue its activities and pay very little attention to the intruder. However, should any hostile action be taken against it, the weasel will make its escape, if possible. If cornered it will savagely defend itself, and as a last resort spray its attacker with the foul-smelling contents of the anal gland. Not so long lasting as the skunk’s perfume, this odorous mist is nearly as effective while it lasts. How much better to stand aside and watch the little predator go about its work!
If you are fortunate enough to be in an area where a hay meadow is being irrigated, you will see the meadow voles (meadow mice) being flooded out of their homes. A careful watch may reveal one or more short-tailed weasels taking their toll of these hapless refugees. You may even find a cache laid away during this period of good hunting. Neither pity the voles nor scorn the weasel; both are only fulfilling their destinies in an ages-old plan.
Range: This species, together with several subspecies, is the common spotted skunk of the Southwest. It has a “spotty” distribution over the whole of the four-State area with which this book is concerned.
Habitat: Common in most situations which offer suitable environment from near sea level, to an elevation of approximately 8,000 feet. Seldom encountered above timberline. These skunks normally live in burrows in the ground, but are not averse to taking up residence under buildings or in the walls or attics of frame houses.
Description: A small, nocturnal, black and white animal about the size of an average grey tree squirrel. Total length about 16 inches, of which 6 inches is taken up by the tail. One description of the color pattern would be to call it marbled. The head usually has a prominent white spot between the eyes, with several smaller spots on the sides of the face. The forequarters are marked with four lateral, irregular white stripes which reach to mid body. The rump is variously blotched with white. Tail very bushy and about half white and half black. Eyes dark in color, ears small. Feet small but plantigrade as in the larger species of skunks. Young number three to six, born in early summer.
Although this little animal has a slight heaviness of the hind quarters, reminiscent of the larger skunks, it is indeed, as both generic and specific names suggest, much more like a weasel. This impression is heightened by its quick movements and a bright-eyed attention to details which its larger relatives would hardly notice. It lacks the wild and fierce disposition of the weasels however, and becomes a charming and confiding nocturnal visitor if properly encouraged. Remember though that this acquaintance can be no more than an armed truce, and that should the articles of Formal Conduct be violated it can be terminated at a moment’s notice.
Probably no nocturnal mammal in the Southwest is more likely to be encountered than this little skunk. How many of my readers can recall drifting up from an uneasy sleep to the sibilant whisper of, “there’s something in the tent.” While eyes strain to pierce the darkness, faint patterings on the floor and urgent scratching at the grub box indicate that there is indeed “something in the tent.” Turning over with the utmost care, while the joints of the cot loudly complain, the flashlight under the pillow is finally extricated. Surely the creature has been frightened away, but no, the rattlings continue—in the dishes now. The brilliant white beam stabs in that direction. Red eyes stare back, interested perhaps, but unafraid. The rounded ball of black and white fluff waits motionless to see if any harm is intended. When none is offered, his highness makes his way to the door and ambles away into the enveloping darkness. In the morning tiny squirrel-like tracks in the dust show that Spilogale has paid a nocturnal call. These, and perhaps the contents missing from the butter and bacon grease containers, because this little animal dearly loves animal fats. These are the foods which attract these animals to camp sites in such numbers that they frequently become a nuisance.
In the wild, spotted skunks live largely on insects. These are taken not only in the adult form but also in great numbers in the larval stage, as is shown by the well-winnowed debris under clumps of cactus and around the bases of shrubs and trees. In these searches for insects small prey of other kinds is captured as circumstances permit. Worms and scorpions as well as small rodents are not refused. More rarely a ground-nesting bird may be disturbed and the eggs or young taken. In rural communities hen roosts are sometimes raided too but in the main the spotted skunk should be considered beneficial, with control of grasshoppers and beetles it’s chief function.
Like most predators, this member of the weasel family has few natural enemies. This is not surprising; few animals willingly take a chance on attacking this doughty little warrior, which sometimes does a handstand the better to spray it’s enemies. These tactics avail nothing against the steely monsters that rush up and down our highways in the dead of night. In the space of 50 years the automobile has developed into the most successful enemy of the spotted skunk. Yet even in death on the highway the skunk has it’s revenge. Few will pass the spot for many a day without paying unwilling tribute to this malodorous legacy.
Range: The southern half of Canada, the whole of the United States, and the northern half of Mexico.
Habitat: All life zones up to timberline in places which have a sufficient food supply and proper cover.
Description: This is the “wood kitty,” approached with due respect by all but the most naive. About the size of a house cat. Total length 22 to 30 inches. Tail 8 to 15 inches. Weight 6 to 10 pounds. Body color is black, with black tail except for the tip, which is commonly white. There are usually two white stripes on the back joining in a “V” at the back of the head and a white stripe down the front of the face. The head is small with a rather pointed nose, small black eyes, and small ears. Front legs are short, and the small feet are tipped with stout claws. Hind legs are longer and appreciably more of the large hind feet touch the ground. The tail is quite long and extremely bushy. It is carried in a downward curve when traveling; if its owner is startled or angry, it is held straight up with the hairs flared out. Dens of the striped skunk are usually in an underground burrow, but dens in hollow logs have been recorded. The usual number of young average from four to six. The family remains together for the greater part of a year before the young leave to make their own way.
There are four species of skunks in the Southwest, but the observer in the higher country will see only two. These are the striped and the spotted. They are distinguished by two characteristics: first, the striped skunk is easily double the size of the spotted skunk; and, second, the spotted has a pattern of broken stripes and spots of white, whereas the larger animal has definitely long, continuous white stripes along sides or back. Both species have the same method of defense, but the odor of the smaller skunk is said to be somewhat less pungent and dissipates sooner than that of the striped. To the recipient of either barrage this has the same consolation as if he were given a choice between being hit by the H bomb or the A bomb. In the event of a direct strike it makes little difference.
Should the reader be involved in an encounter with one of these malodorous creatures, there are many remedies prescribed but few giving any great measure of relief. If the skin is washed with a weak solution of acid such as lemon or tomato juice and then scrubbed thoroughly with soap and water, much of the odor will disappear. Clothes can be given the same treatment, but usually it is cheaper and easier to burn them and charge the cost to experience. Grandpa said to bury scented clothes in damp earth. Perhaps in time this will do the trick; I contend they are better left there.
So much misinformation exists about the skunk’s defensive mechanism and the manner in which it is employed that brief explanation may not be amiss. The scent is a fluid stored in two glands located near the base of the tail. These glands are embedded in a mass of contractile muscle, and each has a duct which connects with a tiny spray nozzle that can be protruded from the anus. When danger threatens the tail is lifted, the nozzles aimed at the enemy, and the contraction of the muscles around the glands forces out a spray of fine droplets which may carry as far as 15 feet. The result is usually effective and lasting. Contrary to popular belief, the odor is distressing to the skunk as well as to its enemy. The tail is kept out of the way if possible, since its plumey depths would hold the scent for a long time.
striped skunk
Skunks of different species will use this defensive weapon against each other. Whether individuals of the same species use it in their fights together is not known. In situations involving humans the skunk will try to bluff the enemy if possible. This consists of stamping the front feet, of short runs at the intruder, and finally of hoisting the tail and aiming the “guns.” If a skunk is approached deliberately and if quick movements are avoided, it is surprising what liberties may be taken before it will resort to scent. On the other hand, should it be taken by surprise or should it be physically hurt, retaliation is swift and certain. In all cases where skunks are encountered at close range, remember that this little animal is one of the most independent creatures on earth, that this nonchalance stems from a supreme confidence in its defensive powers, and that if left alone or at least treated with consideration it will go on its way as soon as possible.
This independent attitude inherent in all skunks probably has much to do with the happy-go-lucky life that the young family lives. About midsummer when the young are able to leave the burrow, the mother often will take them for a stroll early in the afternoon. As she walks, oblivious to danger, the young play along behind her, sometimes a ball of struggling little bodies with now and then a fluffy tail breaking free and again all at odds in a mock show of ferocity with front feet stamping and flared tails held aloft. When the patient mother finds a tidbit on the trail, there is a concerted rush for the prize, which is seldom won without a struggle. All of this is excellent practice against the time when they will be on their own. It is during this early age that the young first learn to catch insects, items of great importance in skunk diet. Later frogs and small mammals will also be preyed upon.
The striped skunk is generally considered a hibernating animal. This is not strictly true for, while it may remain inactive in its den for weeks at a time, the body processes do not slow down to the extent common in true hibernation. The skunk does lay on a considerable amount of fat each fall in preparation for this period of winter when food is scarce. Actual retirement to a den for even a few days is rare in the Southwest, however. The mild climate makes this unnecessary, except in the highest part of their habitat.
Range: At present the range of the black bear in the United States is confined to a narrow strip adjacent to both the Atlantic and Pacific coasts, a few of the southeastern States, a narrow band in the Great Lakes area, and the Rocky Mountain chain.
Habitat: In the Southwest, the higher mountains mostly in the Transition Life Zone and above.
Description: The black bear needs little description because through pictures and reputation it has become well known to almost everyone. It averages 5 to 6 feet in total length with a tail so short as to be inconsequential. Height at shoulders is 2 to 3 feet. Weight 200 to 400 pounds. Color varies in the Southwest from deep, shining black through brown to light cinnamon. In all color phases the nose is brown almost back to the eyes and there is usually a white “blaze” on the chest. The legs are short and muscular. The feet are plantigrade, that is, the bear steps on the whole foot, not just the toes. There are stout claws on all four feet. The head proper is rather round, the muzzle long and pointed. Ears are relatively small, as are the dark eyes. The young number from one to four, with twins being very common. They are born while the mother is still in winter quarters. When the weather moderates to a point where she can leave, the cubs are large enough to follow her.
Bears are probably the most popular of our wild creatures to those who visit the National Park Service areas. Why this should be is hard to say. Perhaps it dates back to the nursery tale of the three bears, familiar to all of us from the time we were able to walk. Perhaps too it stems from the easy familiarity with which these roadside bandits hail the tourist in hopes of a handout. At any rate, these seemingly friendly clowns have become endeared to the hearts of the American public. This is regrettable because actually in the Park Service areas these big carnivores are the most dangerous of all animals. Native intelligence indicates to the bears that food may be had merely by standing up alongside the road when a car stops. More complicated routines are soon learned to wheedle bigger and better handouts. At this professional level, a substantial reward is expected when Bruin has “sung for his supper,” and should none be forthcoming, trouble is apt to ensue. This is but a minor annoyance to a bear, however, when compared with some of the indignities dealt out to these big creatures by a thoughtless public. It must be said in all fairness that anyone who teases a bear deserves whatever is handed out in return. It is unfortunate that retribution may be in the form of serious injury or even death. Though this applies mainly to the half-tame bears which roam along the highways in our National Parks, it is only common sense to avoid incidents with any bear wherever encountered. This is especially true of an old female with cubs, a combination well nigh irresistible to the average vacationer with camera.
In more remote areas where bears have not had contact with man, they are wary to the point of timidity. Gifted with a keen sense of hearing and smell which makes up for their poor eyesight, they are difficult to approach. Like most animals, they instinctively know that by “freezing” they can in most cases escape being seen. The sunburned coat of the brown phase of the black bear is especially hard to spot in the underbrush. However, with patience and the aid of binoculars, it should not be too difficult to get a glimpse into the private life of these engaging creatures.
black bear
Though bears, because of their dentition, are classed as carnivores, they might more accurately be termed omnivores. It is a matter of record that the black bear will eat almost anything, either animal or vegetable. Nevertheless, its appetite is prodigious and demands little variety, if but a few kind of foods are available. Its status as a predator is somewhat confused. Technically speaking, since the black bear preys on ground squirrels, mice and other small rodents it should be classed as a predator. It will also take young deer and elk whenever it can, but these opportunities come rarely. Actually this bear has little direct influence on its mammal neighbors. As a scavenger it has considerable value in cleaning up the remains of kills made by other predators.
Some of the small animals eaten are in almost amusing contrast with the huge size of their enemy. For instance, ants are eagerly lapped up by most bears, and they will literally tear old logs apart to get at these toothsome morsels. Grubs are another small item which may be found around fallen logs and under stones. Bears are extremely fond of honey and will go to great lengths to get at this delicacy, which they eat comb, bees, and all. Another food item which seems unusual is fish. At spawning time a bear will wade out into a stream and either snag a passing fish on its long claws or flip it out on the bank where it is more easily subdued. Finally, their natural animal diet is greatly augmented in most Park Service areas by the scraps and bones which they pick up on the garbage heaps. They can become a great nuisance in the camping areas where, under cover of darkness, their ingenuity and great strength enable them to steal many a ham and side of bacon.
Wide as this variety of animal food seems, it cannot equal the cosmopolitan tastes of these bears in a vegetable diet. Roots and bulbs of many species are dug up. Grass and browse are eaten during several seasons of the year; even pine needles are recorded as having been eaten. The liking of bears for berries of all kinds is well known. Arctostaphylos, the generic name of the manzanitas, translated from the Greek means “bear grape.” Pinyon nuts, acorns, chokecherries, and other stone fruits all are gathered in season. These heavy animals often damage trees severely in their search for fruit. On the garbage heaps, watermelon rinds and seeds, peelings of all kinds, leafy vegetables, and corn cobs add to the fare. All tin cans are licked clean, and in many cases greasy paper and cellophane wrappings are eaten.
The yearly cycle of a bear’s life is a study in contrasts. Much of the warm part of the year is spent in search for food with which to build up a store of fat so that the winter may be spent in inactivity. Bears hibernate or, more properly, retire for several months of the winter. They do not fall into the deep sleep indulged by some of the rodents. Theirs is an uneasy sleep broken by periods of lethargy when they are awake but avoid any activity. By these means they conserve enough of their thick layer of fat to live out the cold weather and emerge in early spring with a considerable reserve.
Hibernation takes place in late autumn, usually after the first light snows. Evidently the animals have a den already located, for when they feel the urge to retire they strike out across country to it. The same winter quarters often will be used by one individual for several seasons. Dens are chosen in a variety of locations. They may be in old hollow logs or in the bases of fire-gutted trees. Some are in crevices among huge boulders, others in caves. The main concern seems to be to find a place sheltered from the wind and snow. If the floor happens to be covered with chips or leaves, so much the better. It usually is, either from air currents which bring in falling leaves or through the labors of woodrats which deposit much litter in such places. The bears curl up on the floor, and after the first heavy snow there is nothing to mark the spot. In the case of a small den, such as a cavity in the base of a tree, an airhole may form in the drift from the warmth of the animal’s respiration.
The cubs are born in late winter. From one to four in number, they are incredibly small at birth. They develop rather slowly and at the time the family emerges from the den are approximately 18 inches long. The cubs may all be one color or some may be brown and some black. The male bear has no part in raising the family; indeed, he is driven from the scene by the irate mother, should he approach too closely. She has all the responsibility for raising the family, and a busy time is assured with such mischievous, carefree youngsters.
One of the first lessons learned by young cubs is that of obedience. The mother insists on compliance with her every command, and enforces her authority with a heavy paw. It is fortunate the cubs are sturdily built, for some of the slaps they receive in the course of an average day’s instruction would kill a less durable animal. The first haven of refuge when danger threatens is in the trees. A special command note and a slap or two sends them hustling. Now the cubs are out of the way and the decks cleared for action, so to speak. The cubs will remain in the trees until the mother lets them know they may come down. This is not a time of boredom for the youngsters, however. Expert climbers, they carry on the same games and rough play indulged on the ground, with never a fall. Their confidence in the trees is amazing. It is not unusual to see a cub sound asleep on the end of a 20-foot branch that is bending down with its weight and swaying in the wind. As the months go on the cubs begin to lose their juvenile ways. By autumn, they have put on enough fat to last the winter. They usually hibernate with the mother, since they remain with her for well over a year. During the following summer they are well able to take care of themselves, and the mother deserts them.
It is normal, rather than unusual, among black bears to breed only every other year. The youngsters usually do not breed until about three years old.
No account of this bear would be complete without mention of the so-called “bear trees.” These are trees situated at the crossroads, that is, near the intersections of bear trails or otherwise prominently located. When a bear encounters one, it stands up and scratches at the bark with its front claws as high as it can reach. Sometimes it will also bite at the bark. Bears have been observed rubbing the sides of their jaws against the bark. Whether this is a way of leaving their scent is not known. It is thought this may be a way of communication with others of the species, but this has not been definitely proven. Many of the trees chosen for this purpose in mountains of the Southwest have been aspens. The heavy black furrows left in the white bark will persist until the death of the tree. Often they are the only evidence that bears have ever been in the locality.
Another custom which will be observed very early in one’s experience with bears is the scratching that goes on. It may be due in part to the presence of ectoparasites, but the bear takes such an obvious satisfaction in scratching that, one feels, this must be only incidental. Trees, posts, rocks, and claws are all employed for this purpose. Some of the smaller trees often suffer severe damage from the treatment accorded them.
My cautious attitude toward bears is a result of early experiences with them, ranging from humorous to tragic, and probably best typified by an incident which took place near Yellowstone Park in the late 1920s. I was on my first trip into the Rockies at the time and hired out on a construction job at an isolated dude ranch. Horses were being used, and their supplies, including a considerable store of oats, were kept in a large tent adjacent to that in which some of the employees slept. On the previous night a bear had gained access to the supply tent, torn open a number of oat sacks, and wasted more of the grain than it had eaten. The foreman, an old-time packer in the Park, vowed vengeance on the bear. That night when he went to bed he leaned a small, double-bitted axe against the entrance to the tent. During the night I awoke as the foreman went out the entrance in his underwear. A partial moon shed a weak light over the scene and revealed the foreman entering the other tent with the axe in his hand. A short silence was followed by a heavy splat, a tremendous grunt, and some frenzied shouts. The supply tent heaved violently, went down, and split open as the bear hurtled out and through the woods toward the creek. When order had been restored it transpired that the foreman had stolen up to the bear, which had its back to him, and had struck it across the rump as hard as he could with the flat of the axe. The element of surprise apparently was all in his favor because the startled bear charged directly away from him into the far end of the tent. Although in this instance no injuries were suffered, it has always seemed that this was an extremely foolhardy thing to do. Although one of the most laughable happenings I have ever seen, it also had all the elements of a possible tragedy.
Range: Alaska, western Canada, and in the United States confined to the high mountains of the Continental Divide as far south as northern New Mexico.
Habitat: Except in National Park areas, grizzlies are seldom seen, since they frequent only the most isolated places in the mountains; Transition Life Zone and higher.
Description: The largest carnivore in the Southwest. Easily distinguished from the black bear by the prominent hump on the shoulders. Total length 6 to 7 feet. Tail so short as to be unnoticeable. Height at shoulders 3 to 3½ feet. Weight 325 to 850 pounds. Color of the southwestern grizzlies is variable, ranging from yellowish brown to nearly black, but has a characteristic grizzled effect caused by the white-tipped hairs scattered through the fur. This is especially noticeable along the back. The grizzly, though massively built, gives an impression of leanness. The shoulders are higher than the posterior, giving the animal a streamlined appearance. The head is large and round with a square, uptilted muzzle. The legs are extremely powerful, the feet large and with formidable claws, those of the front feet being up to 4 inches long. The young will number from one to three, with two being most common. Grizzlies breed every 2 or 3 years.
Probably no mammal in the United States is more certain soon to become extinct than these great bears. Many factors contribute toward this end, chief among them being the low reproduction rate and the rapid decrease of its range because of an increase in stock raising and agriculture. Ousted from its former haunts, the species is now found chiefly in only the few areas where it is rigidly protected. It seems extremely unlikely that it can long survive this reduction of its once unlimited range. This is the culmination of a program of destruction wrought on the grizzly since penetration of the white man into the West. It but follows the disappearance of other, less well known bears which lived in the Southwest at that time.
When the Mountain Men came into the West in the period from 1800 to 1850 they found a huge, light-colored bear roaming the foothills of the desert country. For want of a better name they called it the “gray bear.” From the accounts of that time it is now assumed that it was a grizzly; at any rate, it was said to have been extremely ferocious, a trait which led to its downfall. In the space of about 70 years this animal was discovered, hunted and exterminated, all without a specimen of any kind being preserved. Today not a trace of this big predator remains. Its fate illustrates the usual result of contact between a dangerous, highly specialized animal and man. The question which arises is, should any group of men ever be allowed such control over a wilderness that they are able to exterminate the fauna and flora to the detriment of succeeding generations? The answer seems obvious if we consider that “we but hold these things in trust.”
grizzly bear
Many species of the grizzly are recognized by taxonomists, but few are alive today. In the United States only New Mexico, Colorado, Utah, Wyoming, Montana, and Idaho still have some of these big animals. In some other western States they have but recently become extinct. California is thought to have lost its last grizzly in 1925. The few survivors are probably all of the species horribilis. Since grizzly country is also black bear country, the layman may become confused in identifying the two species. A few important differences make identification easy.
The first and most conspicuous field mark is the prominent shoulder hump of the grizzly. The male black bear will sometimes with age develop a shoulder hump, but it cannot compare with that of the grizzly. Second, the grizzly has what has been described as a “dish” face; that is, a concavity in the general shape of the front of the face, whereas the black bear develops a definite “Roman” nose. Third, the claws of the grizzly are twice as long as those of the black bear; this is most noticeable in the tracks. If one is close enough to see this characteristic in the field, he probably is too close for safety! Lastly, the attitude of the two species toward each other when they meet on common ground is characteristic. As a rule, the approach of a grizzly to a garbage dump is enough to put all black bears to flight. There is no intermingling of the two species; the grizzly is the master and the black bear will not challenge his authority.
In most of its habits the grizzly resembles the black bear. It is omnivorous to the same degree, but somewhat more predatory. It also goes into hibernation for the winter, and the cubs are born during this inactive period. They receive the same rigorous training as that accorded their black cousins, and like them, are able to climb into the trees and out of harm’s way. As they grow older, this ability leaves them with the growing of the long claws, and adult grizzlies are supposed to be unable to climb. In one respect the grizzly differs from not only the black bear but from most other native mammals. It has never learned to fear man to the same degree that other creatures have.
Whether the grizzly’s belligerent attitude stems from fear or contempt is a moot question. The important point to remember is that a grizzly should be avoided at all times. Injuries suffered by humans in their contacts with black bears are usually accidental rather than the result of deliberate assault by the animal. Grizzlies have been known to charge without other provocation than trespass on what they consider their territory. Surely the public can afford to humor this irascible giant. A little consideration for its irritable nature is not too great a price to pay for its continued existence in our rapidly dwindling numbers of large carnivores.
Range: Confined to mountains of western United States and Canada, and northern and southern Mexico.
Habitat: Moist places in forests of the Transition Life Zones and higher.
Description: A tiny creature with a long nose. Total length 4 to 5 inches. Tail 1½ to 2 inches. Color reddish brown to black above with sides drab and lightening to gray below. Tail indistinctly bi-color except for the last half which is dark all the way around. Head round and narrowing to a long, pointed, somewhat flexible nose. Long whiskers are found along the sides of the upper jaw. Eyes and ears so small as to be difficult to see. Little is known of breeding habits of the shrews. The vagrant shrew is said to breed at any time of year and to have from 5 to 11 young in a litter.
Shrews are the smallest American mammals. Their size and secretive habits combine to make them among the least known of native animals. They are classed as insectivores, although they eat other small mammals as well as insects. They may be distinguished from mice by their bicuspid incisors and modified canine teeth. Another difference is that shrews have five toes, in contrast to the four-toed feet of mice.
vagrant shrew
As far as is known at present, certain species of shrews are the only poisonous mammals. The big short-tailed shrew (eastern United States) has a toxic substance in its saliva which helps subdue some of the animals it captures. It is thought that some western species also have this peculiarity. Though shrews are among the tiniest animals known, they are not unduly persecuted by larger predators. This is thought to be partly because of certain glands on the shrew’s body which give it an offensive odor.
An outstanding characteristic of shrews is their need for a constant supply of food. Because all small animals lose heat quickly, they must eat almost constantly to replace this loss. Some species will eat their own weight in food as often as every 3 hours. An outstanding exception is the water shrew, which can do without food for as long as 2 days without starving to death. Since most shrews live in or near the water, they find ample food in the insects, spiders, minnows, and small mammals which live in moist locations. The group is as ferocious as it is voracious. Most shrews do not hesitate to attack animals outweighing them several times. It has been said that if shrews were as big as squirrels they probably would even attack man.
In the mountains of Utah, Colorado, and northern New Mexico the northern water shrew (Sorex palustris) may be encountered. It is somewhat larger than the vagrant shrew and will not be seen away from water. Gray below and black above, it is wonderfully camouflaged, whether in water or on land. It, like other shrews, has long whiskers known as vibrissae. Land shrews use these whiskers as tactile organs to help them follow the dark maze of their runways. Water shrews are thought to use them as sense organs in place of eyes to pursue the minnows, tadpoles, and water bugs they eat. Actually, the water shrew resembles a large water bug as it darts about below the surface surrounded by the silvery bubbles of air imprisoned in its fine fur.
The special treatment accorded bats in this book is not given them by choice. It results from an inability to so clearly describe any one or two species chosen that the layman might be able to distinguish these from their numerous and equally interesting relatives. When one considers that numerically bats are thought to compare favorably with birds, that there are a great number of species divided into many genera, and that the four-State area with which we are concerned is invaded, so to speak, by eastern, northern, western and Mexican species besides having several of its own, it soon becomes apparent that this group can be described here only in the most general way. If some of the popular superstitions about bats are contradicted here, it is to be hoped the reader will find the facts no less interesting.
The adaptation for which bats are best known is their ability to fly. This specialized talent is shared by no other type of mammal. It is made possible by considerable modification of several structures of the body, that of the forelimbs being the most extreme. The bones of both the upper and lower forelegs are considerably lengthened, but cannot compare with the extreme elongation of the digits. The clawlike protuberance from the front of the wing corresponds to the thumb. The wing membrane stretched across the “fingers” is attached to the side of the body and to the hindlegs as far as the ankle. Most bats have another wing membrane, called the interfemoral membrane, which joins both hind legs, and in many species it also embraces the tail. The wing membranes look and feel somewhat like thin leather. Running through them is an intricate system of blood vessels. These not only supply nourishment to the membrane but also act as a radiator in cooling the blood stream during the strenuous physical labor involved in flight. The principles of flight are similar to those used by birds; that is, the wings are partially folded on the upstroke and fully extended during the down beat. This maneuver produces a rustling sound that is clearly audible in the quiet of a cave. In fact, if thousands of bats are disturbed at the same time it becomes a low roar.
The fact that bats are nocturnal, and at the same time lead an aerial life which necessitates flying through labyrinths plunged in total darkness, has been the cause of much research as to the means by which they can do this. It is now definitely known that they depend on a sonar system where, by emitting shrill cries, they are guided by the echoes rebounding from nearby objects. These “squeaks” range within a frequency of from 25,000 to 75,000 vibrations per second, which is too high for the human ear to register. The sounds are uttered at rates from about 10 per second when the bat is at rest to as many as 60 per second when it is in flight and surrounded by the many obstacles to be found in a cave. Fantastic as this performance seems, it is matched by a theory that tiny muscles close the bat’s ears to each squeak and open them again to hear only the echo.
The response of their vocal and hearing structure to this specialized use is truly amazing. There are no more unique faces in the mammal kingdom than those of the bats. Most bats have enormous ears with ridged and channeled interiors that probably have much to do with amplifying faint sounds. Set in front of the ear is a narrow, upright protuberance known as the tragus. Farther down the face, in the region of the nose, are other strangely shaped skin structures including the “nose leaf.” As yet the functions of these appendages are not entirely known, but it is suspected that at least part of their purpose is to beam the squeaks along a definite line and thus help orient the bat with its surroundings. With such an efficient system to guide it, the bat has small need for eyes. The expression “blind as a bat” is misleading, however, because most bats, in spite of their relatively small eyes, can see rather well.
Since most southwestern bats are insectivorous, with the exception of a very few species along the Mexican border which are considered fruit eaters, the question arises as to how they exist during the winter months when insects are not to be found. There are two common methods by which animals avoid such a lean period: by migration and by hibernation. Bats employ both. Some species are thought to fly as far south as Central America. Others group together in caves and hang in a deep torpor all winter. In this state of inactivity their body temperatures may fall to within one degree of their surroundings, and their rate of metabolism sometimes falls to one-eighteenth of that during active periods. As a rule, bats prefer a cool place for hibernation, because the cooler the temperature the slower the rate of metabolism. Body temperatures as low as 33.5° F. have been recorded in hibernating bats. The temperature must not fall below freezing, or the animals will perish. During this period of inactivity bats have been known to lose up to one-third of their weight.
Because of their secretive habits and nocturnal periods of activity, bats have few enemies other than man that are capable of making any serious inroads on their numbers. Consequently the birth rate is quite low in most species. Many have no more than one young each year; and the red bat, which bears up to four young, seems to be the most prolific in the United States. There is great variety in the methods by which different species care for the young. Some mothers leave the babies hanging to the roof of the cave while they go on their nightly search for food; others carry the young clinging tightly to their fur. The young mature quickly. They are usually able to fly within a month after they are born.
Despite much recent scientific study, bats are still among our least known creatures. Their insectivorous diet surely makes them of great importance to man. Beyond this, their immense numbers indicate that ecologically they must have tremendous influence on any area in which they live.