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.
[Illustration: 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.
[Illustration: 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.
[Illustration: 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.
[Illustration: 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.]
[Illustration: 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.
[Illustration: 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.”]
[Illustration: 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.]
[Illustration: 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.]
[Illustration: 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.]
[Illustration: 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.]
[Illustration: 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.]
[Illustration: 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.]
[Illustration: 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.]
[Illustration: 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).]
[Illustration: 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).]
[Illustration: 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.]
[Illustration: 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.]
[Illustration: 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.]
[Illustration: 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.]
[Illustration: 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.]
[Illustration: 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.]
[Illustration: 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).]
[Illustration: 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.