Wild Animals of North America / Intimate Studies of Big and Little Creatures of the Mammal Kingdom

by Edward William Nelson

THE HOARY BAT (Nycteris cinereus)

The hoary bat is a close relative of the red bat described above, but is larger, about five inches long, and, as its name implies, is of a different color. It is widely distributed over a large part of North America, where it is known to breed from Nova Scotia, Manitoba, and the southern shore of Great Slave Lake south practically throughout the United States. It is one of our larger species and is remarkable for its power and skill on the wing. The wings are long and narrow and carry their owner through the air in a bewildering series of swoops, curves, and zigzag turns remarkable even in a group of animals so notable for their powers of flight.

With the approach of cold weather the hoary bat migrates from the northern parts of its range to the milder southern districts. It is a late migrant, not leaving its northern home until the last of September or October and returning in May. Some individuals appear to remain in the North all winter, as one has been taken in Connecticut in December. In its southern flight it wanders as far as Jalisco, near the southern end of the Mexican table-land, to Lower California, and to the Bermuda Islands. To reach the Bermudas it is evident the bat must make a continuous flight from the nearest point on our shores of at least 580 miles—a good tribute to its wing power.

Like the red bat, it lives in the open, hanging from twigs and leaves in the tops of trees or bushes in the broad light of day rather than in the dark, stifling crevices where so many of its kind pass their lives. It appears to hang up indifferently on any convenient tree or bush, including conifers, aspens, or willows. During the day it has a curious lack of alertness, and as it is not rarely attached to low branches or bushes within a few feet of the ground it may be readily approached and taken in the hand. I once captured a fine specimen the middle of May, in southern California, hanging on a bush about four feet from the ground. It appeared to be sound asleep until taken by the skin on the back of the neck, when it became very much alive and, struggling in a fury, uttered grating shrieks of rage, baring its sharp, white teeth and trying desperately to bite.

Its food is made up entirely of insects, which it appears to hunt higher up than most bats, sweeping over the tops of the forest and in and out about the trees. It appears to be of even more solitary habits than the red bat and is nowhere so common. Another reason for our lack of information concerning it is found in its strictly nocturnal habits, for it rarely appears until shortly before the approaching night hides it from view.

The hoary bat shares with the red species the distinction of bearing from two to four young each year. The young are born in June and are carried attached to the underside of the mother’s body until they become too heavy a burden. They hang to the teats with the greatest tenacity and apparently rely mainly on this hold to prevent being dropped as they are carried on the wild aërial hunting excursions. With the unusual fecundity indicated by the number of young, it is difficult to account for the scarcity of these bats unless their habit of hanging in the open, exposed to the elements and to other dangers, may cause a heavy mortality among them.

Note.—The attention of the reader is called to an error on page 566, where the Little Brown Bat, Myotis lucifugus, on the tree trunk, a common species throughout most of North America, is labeled “Hoary Bat, Nycteris cinereus,” which is a much larger and very different animal.

THE TRACK OF A COYOTE

This track cannot be distinguished with certainty from that of a small dog ([see pages 596] and [597]). The greater size of the side toes in the hind track I have often noticed, but there is no corresponding disproportion in the animal’s foot.

THE MEXICAN BAT (Nyctinomus mexicanus and its subspecies)

(For illustration, [see page 567])

Reference has been made in several preceding sketches of this series to the mammals of tropical origin which have invaded our southern border. The Mexican bat is a notable member of this class. It differs in many curious ways from the bats with which it associates in temperate regions. It is smaller than any of the other three bats treated here and is strongly characterized by a flattening of the head and body which enables it to creep into a surprisingly narrow crevice in the rocks or elsewhere. The ears are broad and flaring and extend forward over the eyes like the visor of a cap, and the end of the tail is not confined within the membrane extending between the hind legs, but projects from it. Another pronounced characteristic of this bat and one highly disagreeable is the rank musky odor which it gives out. This pollutes the air about its harboring places, rendering it a most unwelcome guest.

Whoever has visited the Southern and Southwestern States or Mexico must have noted the offensive odor in many places about the verandas of houses and especially about old churches and other public buildings. This is the sign of occupancy placed on the premises by the Mexican bats, which, to the number of a few dozens or actually by thousands, as conditions permit, may lie snugly hidden in cracks and dark openings of all kinds about the roof and walls. No other bat in Mexico or the United States is provided with so strong an odor.

MUSK-OX

Drawn from the tracks of a big bull in the barren grounds of Canada. Much like the track of a common cow ([see page 594]), but more rounded and less deeply cloven; also, I think, less often sprawling—in other words, more often hind foot on front track; for the musk-ox is more of an upland creature.

The Mexican bat is extremely abundant, probably exceeding in numbers any other species within its territory. It ranges throughout the tropical and lower temperate parts of Guatemala, Mexico, and across our border, throughout most of Texas, and east as far as Florida and South Carolina; in the West it also abounds both in town and country in the warmer parts of New Mexico, Arizona, and California.

Closely allied relatives of the Mexican bat abound throughout the warmer parts of Central and South America to beyond Brazil. The genus to which this species belongs is represented in the warmer parts of both hemispheres. It extends north in the Old World to southern Europe and also is found in the Philippines.

The abundance of the Mexican bat in some favorable places is almost incredible. At Tucson, Arizona, I once saw them, a short time before dark, issuing from a small window in the gable of a church in such numbers that in the half light they gave the appearance of smoke pouring out of the opening. At times they occupy houses in such numbers that their presence and accompanying offensive odor render the places uninhabitable. At the town of Patzcuaro, near the southern end of the Mexican table-land, I saw two rooms in an old adobe house occupied by as many of them as could possibly hang from the rough ceiling. The owner considered their presence a valuable asset, as he collected and sold the guano for more than the rooms would have brought in rent. The bats congregate in even greater numbers in large caves. So numerous are they in certain caves in Texas that the owner reports an annual income of about $7,000 from the guano.

They are very plentiful by day in the thin crevices about the roof and walls of caves in the celebrated Ixtapalapa, or “Hill of the Star,” beyond the floating gardens at the City of Mexico, and I also found them living in many of the marvelous ruins of Mexico, including Chichen-Itza, in Yucatan. Wherever they occur in numbers they may be heard frequently by day shuffling uneasily about and squeaking shrilly at one another.

BADGER

The huge fore claws are a strong feature. The hind claws rarely show in the track. The broad spread of the tracks in the lower trail corresponds with the low, thick form of the animal.

When they first come out after sunset they usually fly away in a great stream, nearly all in the same direction, as though migrating. This course will probably be found leading to water, where they scoop up a drink from the surface before beginning their wonderfully erratic zigzags through the air in pursuit of insects.

From the colder northern parts of their range they migrate southward to milder climatic conditions or descend to lower altitudes. In Mexico, where they live up to above 8,000 feet altitude, they move down from one to two thousand feet. Their young, one at a birth, are born from April to May.

It has been claimed that the Mexican bat brings bedbugs to infest houses. This is untrue of this or any other bat. These animals have certain small parasites, some of which, resembling small bedbugs, have probably given rise to the belief mentioned. These parasites live only on the bats.

THE TRACK OF A BIG BULL MOOSE WALKING ON HARD GROUND

The great size, the pointed shape, and the long stride usually distinguish it from the track of a domestic cow. Ordinarily, the clouts do not show. The dung pellets, however, are very important diagnostics. They are cylindrical, about ⅝ inch through and 1¼ inches long. Probabilities of time and place must always be considered. Oftentimes the hind foot is set far ahead of the front-foot track. The excessive spreading of the hoofs is a strong character of moose tracks.

TRACK OF A COW MOOSE WALKING IN THREE OR FOUR INCHES OF MUD

In this the clouts show clearly. The excessive pointedness of the cow’s track is not a fixed character. The hoofs of a moose in swamp country are larger and more pointed than those in a rocky country, because less worn. The cow track, in this case, was sketched in a land of swamps, so that it is longer and sharper than the average.

Within a few years considerable publicity has been given to the supposed possibility of utilizing bats to destroy mosquitoes and thus eliminate malaria from infested areas. One or more bat houses have been built at San Antonio, Texas, for the purpose of assembling bats in large numbers, and many untenable claims have been put forth concerning the benefit to be derived from their services. The Mexican bat is the species which abounds above all others at San Antonio and is the principal species which has occupied the bat houses near town. It is definitely known that bats often fly miles from their roosts when feeding and do not concentrate on any one kind of insect. Examination of the contents of the stomachs of Mexican bats shows that they feed on beetles and numerous other insects, but rarely upon mosquitoes. I have visited many Mexican towns and villages in which every house was haunted by numbers of these bats and where malaria was perennial. The evidence against these animals serving any useful purpose in checking malaria is conclusive.

It may be repeated here, however, that all of our bats are of high utility as insect-destroyers and should be protected. Among the many species of varying habits which exist in the United States, a few make their homes about houses in annoying numbers. In place of killing them to abate the nuisance, it would be better to exclude them from buildings by closing the entrance ways promptly after all have left in the evening, and thus by quiet eviction cause them to find abiding places elsewhere. The destruction of forests, and the consequent absence of the hollow trees where they formerly lived, is mainly responsible for bats and chimney swifts coming to houses for harbor.

THE BIG-EARED DESERT BAT (Antrozous pallidus and its relatives)

(For illustration, [see page 567])

The marvelous variations in structure of the ears and other organs about the heads of insect-eating bats serve probably as microphones by which the flight of their prey may be detected and its direction located with instantaneous certainty. The beautiful accuracy with which this hearing mechanism works must be evident to any one who will take a position where he may have the evening glow of the western sky as a background for flights of bats. It is certain that the small and ineffective eyes these animals possess could never locate their minute flying game and enable them to secure it in the whirling, zigzag courses they pursue, often at a speed and under a control which few, if any, birds could rival.

The great ears of the big-eared desert bats illustrate one form of a highly developed hearing apparatus and give these animals a handsome and strikingly picturesque appearance. This character at once distinguishes them from others of their kind in the United States.

The distribution of this species lies mainly in the arid parts of the Southwestern States and Mexico. It extends from western Texas, southern Colorado, Nevada, and Oregon, south to Queretaro, on the Mexican table-land, and to the southern end of the peninsula of Lower California. The vertical distribution extends from sea-level up to at least 5,000 feet altitude.

By day these desert bats live in crevices and caves in cliffs, in old mining tunnels, hollows in trees, and in sheltered places about the roofs and walls of houses, barns, or other buildings. Their presence in dark hiding places may sometimes be detected by occasional grating squeaks. They appear to lack any musky odor which characterizes so many bats. About the 1st of June each year either one or two young are born, and for a time these cling to the mother’s breast and are carried during her swift flights in pursuit of insect prey.

Often when camping at desert waterholes, I have seen them come in just before dark to drink, scooping up water from the surface while in flight, and then circling back and forth over the damp ground at an elevation of a few yards for the capture of some of the insects common in such places. At such times, with the distant hills mantled with a deepening purple haze and the pulsating heat of the day replaced by the milder temperature of approaching night, these bats could often be seen sharply outlined against the rich orange afterglow of the departed sun. Here and there in the still air flickered and zigzagged multitudes of tiny bats, like black butterflies, and among them the occasional big-eared bats on broad wings appeared huge in contrast. Their wing strokes were slower and shorter than those of the smaller species and impelled them forward in a swift, gliding movement which gave their evolutions a sweeping grace beautiful to see.

In August several years ago, during a visit to the Indian School at Tuba, in the Painted Desert of northern Arizona, I found these bats living in considerable numbers about the buildings. Just before dark they swarmed out and hunted about the surrounding orchards and small fields. One evening my collector shot at one as it circled over a potato field in a small orchard. It continued its flight, circling low among the apple trees as though unhurt, when suddenly it dropped to the ground. Supposing the bat to be wounded, it was cautiously approached and covered with a hat, when, without a struggle, it permitted itself to be picked up by the nape. It then became evident that the bat was unhurt from the shot. The reason for its sudden descent was revealed in the person of a large, fat mole cricket (Stenopalmatus fuscus) which it was holding firmly in its jaws, and so ferociously intent was it in biting and worrying its luscious prey that it paid not the slightest attention to its captor. Finally it was killed by having its chest compressed and died with its bull-dog grip on its prey unbroken.

These bats, like the other members of the tribe in the United States, are fully as beneficial to the farmer as the best of our insect-eating birds and deserve equal protection in place of the general persecution from which they now suffer.

ROCKY MOUNTAIN GOAT

Kinship with sheep and antelope is reflected in the track of the goat. Its heel-pads are so large and rubber-like that the track is rarely so sharp as here shown. “Although marvelously surefooted and fearless in traversing the faces of high precipitous slopes, goats lack the springy grace and vivacity of mountain sheep and move with comparative deliberation.”

BIGHORN

The general style of a bighorn track is like that of deer, but the toes are finished off more squarely and the hollow in the outer edge of each hoof is a strong characteristic. Sometimes the tracks are in correct register. The clouts rarely show. The dung pellets are like those of the deer, but rounder. The track is that of a ewe; the ram’s is similar, but larger.

MOUNTAIN LION, OR COUGAR

The track of a mountain lion is much like that of a house cat, differing only in size. Sometimes, as in the cat, the hind foot is set exactly on the track of the front foot.

GRAY WOLF

The track is that of a large wolf. There is no certain way of distinguishing it from that of a dog ([see page 597]). Size and probabilities must be considered.

WHITE-TAILED DEER WALKING

The track of the white-tail is ideal—a starting point to study all the tracks. Sometimes the hind foot fits on the front track, but sometimes not.

WHITE-TAILED DEER BOUNDING

In these the clouts are clearly shown. Note the resemblance to the tracks of the moose ([see page 602]), which differ chiefly in their greater size.

WHITE-TAILED DOE WALKING

This track differs from that of the buck in being smaller, slimmer, and in having the toes pointing forward or inward—rarely outward.

ELK

This shows the track of a large male walking. Each hoof-mark is about 4½ inches long. Had it been five inches it would have meant a very large bull. The track is strictly deer-like in type, but has a little of the roundness of point that is so marked in the domestic cow. At the upper end of the drawing is snow one inch deep. Here no clouts show; at the lower end it is three inches deep, so the clout-marks are clear. Size is essential in distinguishing the track. The dung pellets, about ⅝ × ⅛ inch, are also important.

MULE DEER

The mule deer tread cannot be distinguished with certainty from that of white-tailed or coast deer; yet it averages larger than either of these, and the curious close set together of all four feet while it does its peculiar bounding is quite unlike what we see in the white-tail track. “These deer are not good runners in the open. On level country in Arizona I have ridden after and readily overtaken parties of them within a mile. The moment rough country was reached, however, with amazing celerity a series of mighty leaps carries them away” ([see page 456]).

GRIZZLY BEAR

The great size and the immense claws are the chief characteristics of the grizzly’s track. All five toes usually show in each track. “The strongest and most distinctive characteristic of the grizzlies is the long, proportionately slender and slightly curved claws of the front feet, sometimes more than three inches long” (see [pages 440] and [442]).

BLACK BEAR

The plantigrade foot is clearly shown in the bear track. That of a black bear differs from that of a grizzly, first in size, second in the shortness of the claws. Usually no claws show, and the fifth toe, which is well developed on both front and hind paws, leaves little sign and often none at all. Frequently the hind foot is set on the track of the front foot in correct register.

THE HUMAN FOOTPRINTS

The footprints of the human animal are included in this series of sketches for the purpose of comparison. Especially interesting is the similarity to be noted between the tracks made by man and those of the grizzly and the black bear ([see page 608]). The tracks shown on the left half of this page present the moccasin-shod footprints of a Sioux Indian compared with the shoe tracks of a white man. On the right are shown: (A) a woman’s foot which has been much pinched by tight shoes; (B) a sturdy boy’s foot, somewhat too flat to be normal; (C) the footprint of a slender man, and (D) the imprint of a robust man’s foot.

THE HORSE

A hunter needs to know horse tracks as much as those of wild game. The greater size and roundness of horse tracks distinguish them from those of mules and asses. When shod the toe calks are a strong feature; when without shoes the unbroken front edge is distinctive. Some horses walk in correct register; some do not. Mules are more exact than horses. When trotting the arrangement is much as in walking, but the spaces are longer and the hind-feet track farther ahead of the front feet. In galloping the arrangement is much as in the white-tailed deer.

BARREN GROUND CARIBOU

The caribou track is distinguished by its great spread and the fact that the clouts or hind hoofs touch the ground, even on a hard surface. I know of no difference but size between the tracks of the various caribou and reindeer. The probabilities of time and locality help in determining the species, but it need never be mistaken for that of any other type of deer. In winter the caribou’s tracks in the snow show that its feet, instead of being raised high at each step, like those of a Virginia or mule deer, drag through the snow like those of domestic cattle.

COAST BLACK-TAILED DOE

I know of nothing but probabilities to distinguish the walking tracks of the coast deer from those of nearly related species. This track of a bounding female shows a peculiar grouping that corresponds fairly with the bounding action characteristic of the species.

ANTELOPE

The different styles of front and back feet is a marked character of the antelope’s track and is best seen in the walk. In galloping all of these animals leave the hind tracks ahead of the fore tracks, but disturb the ground, so that almost no characteristic marks are to be seen.

CANADA LYNX

This track I sketched on the Athabasca River. In summer the track of a lynx shows the toe-pads faintly; in winter all are muffled in hair and the track is much larger. “The feet in winter are so broad that they serve admirably for support in deep snow” ([see page 409]).

TEXAN WILDCAT

This track, while akin to that of a cat ([see page 487]), has some very well-marked characteristics. The complicated outline of the heel-pads is striking. This, with its large size, will distinguish it from the track of a house cat. The claws do not show.

[Reprinted from Science, N. S., Vol. XLVIII., No. 1248, Pages 547-549, November 29, 1918

Wild Animals of North America: Intimate Studies of Big and Little Creatures of the Mammal Kingdom. By Edward W. Nelson. Natural-Color Portraits from Paintings by Louis Agassiz Fuertes. Track Sketches by Ernest Thompson Seton. Published by the National Geographic Society, Washington, D. C., U. S. A.; 8vo, pp. + 385-612, folded frontispiece, 108 colored illustrations on text paper (not plates), 85 halftone illustrations. [This is essentially a reprint of two articles which appeared in the National Geographic Magazine, for November, 1916, and May, 1918. The changes comprise repaging beyond page 472, the readjustment of the matter on pages 473-475, the replacement of a half-tone on page 475, the rectification of page references to illustrations to accord with the new paging where needed, and readjustment of the matter from page 571 on, so as to admit 32 new illustrations of footprints and the captions to these.

This is a work which meets to a gratifying degree the need for an essentially non-technical treatise upon the natural history of the mammals of North America. No living person is better equipped to carry to a successful conclusion such an undertaking than is its author. Nelson has contributed in the field of vertebrate zoology now for over forty years, to be explicit, beginning in July, 1876 (Bulletin Nuttall Ornithological Club, Vol. 1, p. 39). With a background of long experience in the field, and with further years of official connection with the United States Biological Survey and its unique resources in mammalogy, he has made available a brochure of pleasing amplitude and satisfying authoritativeness.

Between the colored pictures and the written sketches the public can gain from this contribution a better idea of our principal mammals than from any other available publication. It should awaken a generally greater interest in our native mammals, and this will help build up a desire for the conservation of the harmless and useful species such as has resulted from the public education in relation to our bird life. On the other hand it is important to be able to distinguish those mammals, chiefly of the order Rodentia, which are thoroughly inimical to human interests. People at large must know how to cope with these enemies. It would seem that a full knowledge of the natural history of such animals is essential to determining the most successful means of controlling them and to applying these means properly to the varying conditions throughout the country. Nelson’s accounts of our injurious mammals are full of stimulative suggestions along these lines, and while the work as a whole can not be considered as an “economic” publication, its influence will go far to secure adequate popular consideration of these matters.

The species are taken up in groups, in so far as this can be done safely. Each biography, of which there are 119, is, as a rule, a composite applying to a number of near-related forms, thus simplifying matters of presentation, and avoiding repetition. A marked feature of the book is the degree of concentration attained; there is no trace of padding, and no room for baseless speculation, sentimentalizing or humanizing, such as characterize many current “nature” books. At the same time the style is animated and thoroughly entertaining, a gift of composition which Nelson has exercised in many preceding contributions. Here is an instance, unfortunately a rare one, in which a man who really knows the field has put out a popular book on a natural history subject.

Many are the portrayals which are evidently based on Nelson’s own personal field knowledge, some of them involving facts here for the first time made known to science. His account of the behavior of kangaroo rats in Lower California is particularly apt in illustration of the above statement.

During several nights I passed hours watching at close range the habits of these curious animals. As I sat quietly on a mess box in their midst ... [they] would forage all about with swift gliding movements, repeatedly running across my bare feet. Any sudden movement startled them and all would dart away for a moment, but quickly return.... They were so intent on the food [grains of rice put out for them] that at times I had no difficulty in reaching slowly down and closing my hand over their backs. I did this dozens of times, and after a slight struggle they always became quiet until again placed on the ground, when they at once renewed their search for food as though no interruption had occurred.... While occupied in this rivalry for food they became surprisingly pugnacious. If one was working at the rice pile and another rat or a pocket mouse approached, it immediately darted at the intruder and drove it away. The mode of attack was to rush at an intruder and, leaping upon its back, give a vigorous downward kick with its strong hind feet.... Sometimes an intruder, bolder than the others, would run only two or three yards and then suddenly turn and face the pursuer, sitting up on its hind feet like a little kangaroo. The pursuer at once assumed the same nearly upright position, with its fore feet close to its breast. Both would then begin to hop about watching for an opening. Suddenly one would leap at the other, striking with its hind feet, ... [producing] a distinct little thump and the victim rolled over on the ground. After receiving two or three kicks the weaker of the combatants would run away. The thump made by the kick when they were fighting solved the mystery which had covered this sound heard repeatedly during my nights at this camp.

The brilliantly coated paper used throughout this book although hard on sensitive eyes, is necessary to the handling of the halftone illustrations. The printing of both the colored and uncolored pictures in all the copies we have seen has been done with pronounced success. The color drawings by Fuertes are admirable and we are astonished at the success with which this noted bird artist was able to turn to mammals, the drawings of which in this contribution mark as far as we know his first efforts in the new field.

A critical reviewer might succeed in finding a number of small points to elaborate upon and of which to complain. For instance: It is trite to say that an Alaska brown bear is no more an animal than is a house fly. Yet here we have the title, “Wild Animals of North America,” though there is an evident effort made in the subtitle to remedy the matter by using the expression, “mammal kingdom.” But here a taxonomic blunder is tumbled into! We can hardly believe that Nelson himself had anything final to say with regard to the title page of this book, but that the editor of the National Geographic Magazine got in his work here in the belief so characteristic of editors of popular magazines that their public must be talked down to.

But to pin the attention of the reader of this review upon such really minute defects would do violence to the facts in the case, which are that, according to the convictions of the reviewer, Nelson’s “Wild Animals of North America” is more uniformly accurate and at the same time replete with information along many lines than any preceding book on American mammals. And even more, it may be declared with confidence that this book is by far the most important contribution of a non-systematic nature that has appeared in its field in America.

Joseph Grinnell

Museum of Vertebrate Zoology,
University of California