_Mus musculus_]
Veritable colonies inhabit certain areas and the ground is honeycombed
with burrows six to eight inches in diameter and covered with a network
of surface trails. The irregular branching tunnels are sometimes two
or three hundred feet in length and have at frequent intervals side
passages through which the earth mined in extending the burrow may be
ejected in small dumps. The tunnels appear in a large measure built for
the safety of the owner in traveling, since they repeatedly come to the
surface at the end of a log, where an open, neatly kept trail extends
under its shelter the entire length, the tunnel being resumed at the
far end of the log.
All surface runways connecting tunnel entrances or leading through the
thick surface vegetation are well kept and free of all obstructions.
The ground in these haunts is commonly so saturated with water that the
tunnels form drainage channels down which run little streams.
Nest chambers discovered by T. H. Scheffer in the Olympic Mountains
were located in tunnels two feet underground. They were oval in form
and one measured eighteen inches in horizontal diameter and seventeen
in height. Here three storage chambers opened directly from the nest
chamber, one of which contained two quarts or more of sections of fern
roots, which had been kept so long they were spoiled, and another was
partly filled with freshly cut leaves of nettles and twigs of cedar
and fir. At the far end an opening dropped six inches into a small
drainage basin partly filled with water, out of which led two passages.
The roofs of the chambers were lined with a thin layer of clay, which
appeared to have been packed in place by the owner.
In the upper and drier part of the nest, which was made of dried fronds
of ferns, grasses, and small twigs, were found three young less than
a week old, with coats of fine fur, but with eyes still closed. Like
burrowing animals generally, the mountain-beaver is cleanly in its
housekeeping, and offal, loose dirt, and debris of all kinds are pushed
out by the forefeet and head to the dumps at the less-used openings.
In winter much of the mountain-beaver country is buried under several
feet of snow, but this does not stop the activities of this hardy
animal. Between the entrances to its burrows and out along the surface
of the ground it tunnels through the snow in various directions in
search of forage.
At this time it cuts twigs from bushes and gnaws the bark from the
trunks and roots of the smaller trees, sometimes completely girdling
and killing trees more than two feet in diameter. Its underground
tunnels are also extended at this season, the soils being pushed up
in dumps under the snow and parts of the snow tunnels are packed full
of it for some distance, so that when the snow disappears the curious
earth-forms remain like those of the pocket gopher.
The mountain-beaver lives a monotonous existence and correspondingly
lacks the mental vivacity of many other species which have a greater
freedom of movement. When one is caught it shows little fear, but
struggles to escape, growling, clattering its teeth, and biting
viciously at anything within reach. Its desire for food, however,
appears to control its emotions, and very soon after being captured it
will eat any green vegetation offered, as unconcernedly as though free.
That the mountain-beaver possesses social instincts is evident, as a
pair is often found occupying one set of tunnels, and in many favorable
places a number will have their burrows closely grouped and connected
with a network of communicating surface trails.
Although mainly nocturnal, the animals are active early in the morning
and late in the afternoon, as well as throughout dark days. Those kept
in captivity would show periods of restless activity at night and have
alternating periods of sleep and wakefulness during the day. Sometimes
they would sleep coiled with the head turned under the body and again
flat on their backs. During these periods their sleep is often so
profound that they may be handled without being awakened.
One captive animal is reported to have uttered a curious quavering note
resembling that of a screech-owl. They have a strong musky odor, which
is very evident when they are first caught, and which is frequently
apparent about the burrows.
Careful and repeated efforts to keep these animals in captivity
under as near normal conditions as possible in regard to food and
surroundings in the vicinity of where they were captured have, up to
the present time, resulted in failure. In every case the animals failed
to thrive and soon died.
The mating occurs about the middle of March, and a month later litters
of two or three young are born. The young grow slowly, not attaining
full size for a year or more, and do not breed until the second year,
but they leave the shelter of the home nest and scatter to occupy
burrows of their own at the end of the first two or three months.
The mountain-beaver feeds upon nearly all small vegetation growing in
its haunts, including, in addition to small herbage, shrubs, the bark
of trees and bushes, ferns, and fern roots. More than thirty species of
native plants have been found among its “hay” piles at the mouths of
burrows. Since its country has become increasingly occupied by farmers,
it has developed a fondness for cultivated crops that, in many places,
is rendering it a pest. It appears to have a special taste for cabbage,
potato, and onion tops, and other garden produce.
When gathering its food it sits up squirrel-like and grasps the plant
stem with one hand, a long projecting tubercle on the “heel” of the
hand opposing the fingers like a thumb and giving a good grasp, so that
it can pull plants down to be bitten off with the sharp front teeth.
Sometimes it climbs up a few feet into a bush or small branching tree
after succulent shoots.
The mountain-beaver has the interesting habit of gathering stores of
green plant food much like that of the cony on the mountain tops,
but appears to be more methodical in its ways, gathering the stems
of such plants as grasses, ferns, and lupins, as well as twigs of
various bushes and carrying them in bundles as large as can be held in
the mouth, the butts of the stems neatly laid together. These little
bundles of “hay” are placed side by side about the entrances of the
burrows, with the butts all parallel on sticks or other support to keep
them as clear as possible from the ground. They are left thus for a day
or more to cure before being carried into the subterranean store-rooms.
Chief among the four-footed enemies of the mountain-beaver are the
fisher and bobcat, and an eagle has been seen keeping close watch at
the entrance of their burrows.
=THE COMMON WOODCHUCK, OR AMERICAN MARMOT= (=Marmota monax=
and its relatives)
(_For illustration, see page 534_)
The woodchuck or “groundhog” is a typical marmot, with coarse hair,
heavy body, short neck, short, bushy tail, powerful legs, and feet
armed with strong claws for digging. When fully grown it averages about
ten pounds in weight. Its usual color is a grizzled brown, but in some
districts black, or melanistic, individuals are not uncommon.
Marmots are common to Europe, Asia, and North America. The group
contains many species and geographic races varying in size and color.
The Alpine marmot of Europe is probably the most familiar of the Old
World species and the woodchuck the best known in America.
North America contains several species of marmots, their joint
territory extending from coast to coast over the northern parts of the
continent and from southern Labrador, the southern shores of Hudson Bay
and Great Slave Lake, and central Alaska southward to northern Alabama,
and along the high mountains to New Mexico and the southern Sierra
Nevada of California. The common woodchuck is well known to every
dweller in the countryside of the Eastern States and Canada, where it
occurs from sea-level to near the tops of the highest mountains, at
altitudes of over 4,000 feet.
It is a familiar habitant of fields and grassy hillsides, especially
where bordering woodland offers safe retreat. In such places it digs
burrows under stone walls, rocks, ledges, old stumps, or even out in
the open grass-grown fields. It commonly lives in the midst of the
forest, where its dens are located in a variety of situations. The
burrows are marked by little mounds of earth at the entrances and
ordinarily contain from twenty to forty feet of branching galleries,
one or more of which end in a rounded chamber about a foot in diameter,
well lined with dry grass and leaves.
Within these warm nests the females bring forth from three to nine
blind and helpless young about the last of April or early in May. A few
weeks later the young appear about the entrance of the burrows sunning
themselves and playing with one another, but usually ready to disappear
at the first alarm. At times, however, they are surprisingly stupid
and may be captured with ease. Woodchucks have practically no economic
value. Their flesh, while occasionally eaten, is little esteemed, and
their coarsely haired pelts are worthless as fur.
The woodchuck is a sluggish and stupid animal, which does not
ordinarily go far from its burrow, but at certain seasons, especially
in spring, wanders widely, as though looking over its territory before
locating for the summer. It has much curiosity and often sits upright
on its hind feet to look about, remaining for a long time as motionless
as a statue. When one is driven into its burrow, if a person approaches
quietly and whistles, it will often raise its head in the entrance and
look about to satisfy its curiosity.
Its only note is a short shrill whistle, which it utters explosively at
frequent intervals when much alarmed. At such times it also chatters
its teeth with a rattling sound as owls sometimes clatter their beaks.
Owing to their mainly diurnal habits and persistence in living in and
about the borders of fields, woodchucks are among the most widely known
of our smaller mammals, and have long been the favorite game of the
country boy and his dog. When cornered they will fight savagely and
with their strong incisors inflict severe wounds.
They feed on grasses, clover, and other succulent plants, including
various cultivated crops, especially vegetables in field and garden,
where they sometimes do much damage. The holes and earth mounds they
make in fields, in addition to feeding on and trampling down grasses
or grain, excite a strong feeling against them, and farmers everywhere
look upon them as a nuisance. In New Hampshire so great was the
prejudice against them that in 1883 a law was passed placing a bounty
of ten cents each on them: “_Provided_, That no bounty shall be paid
for any woodchuck killed on Sunday.”
Unlike many rodents, the woodchucks do not lay up stores of food
for winter. As summer draws to an end they feed heavily and become
excessively fat. On the approach of cold weather they become more
and more sluggish, appearing above ground with decreasing frequency
until from the end of September to the first of November, according to
locality, they retire to their burrows and begin the long hibernating
sleep which continues until the approach of spring.
[Illustration: MOUNTAIN-BEAVER
_Aplodontia rufa phaea_]
[Illustration: COMMON WOODCHUCK, or AMERICAN MARMOT
_Marmota monax_]
[Illustration: HOARY MARMOT, or WHISTLER
_Marmota caligata_]
Some time between February and April, according to latitude, they
come forth to resume their seasonal activities. In the northern parts
of their range they usually come out several weeks before the snow
disappears and may be tracked in it as they wander about searching for
food or a new location.
The prominence of the groundhog as a popular figure in the country lore
of the Eastern States is shown by his having been given a place with
the Saints on the calendar, February 2 being widely known as “Groundhog
Day.” It is claimed that on this date the groundhog wakes from his
long winter sleep and appears at the mouth of his burrow to look about
and survey the weather. If the sun shines so that he can see his
shadow, bad weather is indicated and he retires to resume his sleep for
another six weeks. Otherwise, the winter is broken and mild weather is
predicted. Even on the outskirts of Washington some of the countrymen
still appraise the character of the coming spring by the weather on
“Groundhog Day.”
=THE HOARY MARMOT, OR WHISTLER= (=Marmota caligata= and its
relatives)
(_For illustration, see page 535_)
The whistler is the largest and handsomest of the American marmots. It
is similar in proportions to the common woodchuck, but averages nearly
twice its weight. Its fur, far thicker and of a better quality, might
have a value in the fur trade if enough of the skins were available. As
it is, the skins are used only for robes and sometimes for clothing by
the Indians.
The distribution of this characteristic animal of the northern Rocky
Mountains and outlying ranges extends from the Endicott Mountains,
fronting the Arctic coast of Alaska, and the peninsula of Alaska,
southeasterly to the Bitterroot Mountains of Idaho, Mount Rainier,
the Olympics of Washington, and Vancouver Island. In the North its
range extends from above timber-line down over hare slopes and through
glacial valleys to the sea-level along the southern coast of Alaska. To
the southward it is limited wholly to the higher elevations, usually
above timber-line.
Owing to variations in climatic conditions and to isolation in
different parts of its range, several geographic races of the whistler
have been developed. In the mountains to the southward of its range
other marmots occur as far as New Mexico and California.
When the French-Canadian voyageurs on their fur-trading expeditions
first visited the Rocky Mountains they encountered the hoary marmots
and applied to them the name “siffleur,” or whistler, which they had
already given the common woodchuck of eastern Canada. The shrill note
of the hoary marmot, under favorable circumstances, may be heard more
than a mile and justifies the restriction of the name whistler to it.
The whistler lives in such remote and unfrequented districts that
little is known of its life history. It is diurnal in habits and loves
the free open spaces of the high mountain ridges. There its loud,
oft-repeated call note, striking colors, together with its habit of
running about on the snowbanks, render it unusually conspicuous.
High in the mountains it usually inhabits rock slides, the tumbled rock
masses of glacial moraines, or rocky points, but sometimes takes up its
abode on open earth slopes or in the bottoms of little glacial valleys.
Ordinarily the dens are hidden in the rock slides and broken-down
ledges, or burrows are dug under the shelter of large boulders and even
in open ground away from any rocky shelter.
During the sunny days of summer the whistler regularly frequents the
top of some conspicuous boulder or projecting rocky point, from which
it commands a sweeping view of all its surroundings. Its sight and
hearing are extraordinarily keen, and when perched on its lookout it is
difficult to stalk. When one has its burrow located in an open place it
often sits upright on its haunches to look watchfully about, and at the
first alarm disappears into its den. This watchfulness is necessary,
for even in the remote alpine highlands it occupies, the whistler is
beset by enemies. The most formidable of these are the great brown and
grizzly bears of the North, which dig it from its burrow. In addition
prowling wolves, Canada lynxes, wolverines, and eagles take occasional
toll from its numbers.
Toward the end of summer, when the high alpine slopes are thickly grown
with small flowering herbage, the whistler feeds heavily on many of the
plants and, like the woodchuck at this season, becomes excessively fat.
Before the arrival of winter it retires to the shelter of its den and
begins the long hibernating sleep which may last six months or more. In
spring, before the snowy mantle is gone from the mountains, it is out,
ready to welcome the approaching summer. A few weeks later the three or
four young are born. They remain with the mother throughout the season
and during their first winter may hibernate in the home den.
The unspoiled wilderness of remote northern mountain slopes and ridges
where the whistler lives is also the home of the mountain sheep,
caribou, and huge northern bears. As the hardy sportsmen roam these
inspiring heights in search of game their attention is constantly
attracted to the marmots, whose presence and shrill call notes lend a
pleasing touch of life to many an otherwise harsh and forbidding scene.
=THE PRAIRIE-DOG= (=Cynomys ludovicianus= and its relatives)
(_For illustration, see page 538_)
Prairie-dogs are not “dogs,” but typical rodents, first cousins to the
ground squirrels, or spermophiles. As a rule, they may be distinguished
from the ground squirrels by their larger size, proportionately
shorter and heavier bodies, and shorter tails. In length they vary from
fourteen to over seventeen inches, and in weight from one and one-half
to more than three pounds.
These rodents are limited to the interior of North America and form
a small group of five species and several geographic races. Although
closely alike in general form and habits, the species are divided into
two sets: one, the most widely distributed and best known, having the
tails tipped with black, and the other having the tails tipped with
white.
On the treeless western plains and valleys from North Dakota and
Montana to Texas and thence west across the Rocky Mountains to Utah
and Arizona, they are one of the most numerous and characteristic
animals. Southward they range into northwestern Chihuahua and one
species occupies an isolated area on the Mexican table-land in southern
Coahuila and northern San Luis Potosi, Mexico. Their vertical range
varies from about 2,000 feet on the plains to above 10,000 feet in the
mountainous parts of Colorado and Arizona.
Owing to their diurnal habits, their exceeding abundance over vast
areas, and their interesting mode of living in colonies, prairie-dogs
have always attracted the attention of travelers and have become one
of the most widely known of our smaller mammals. All who have lived
in the West, or who have merely traversed the Great Plains on the
transcontinental railroads, have had their interest excited by these
plump little animals sitting bolt upright by the mounds which mark the
entrances to their burrows, or scampering panicstricken for shelter as
the train roars through their “towns.”
So strong is the gregarious instinct in prairie-dogs that they
customarily make their burrows within short distances of each other,
varying from a few yards to a few rods apart. The inhabitants of these
communities, or “towns,” as they have often been termed, vary in number
from a few individuals to millions. In western Texas one continuous
colony is about 250 miles long and 100 miles wide. In the entire State
of Texas 90,000 square miles are occupied by prairie-dogs, and the
number of these animals within this area runs into the hundreds of
millions. The extent to which they occupy parts of their territory is
well illustrated by one situation in a mountain valley, containing
about a square mile, in eastern Arizona, which by actual count
contained 7,200 of their burrows.
The burrows, from four to five inches in diameter, are usually located
on flat or gently sloping ground. They descend abruptly from eight to
sixteen feet, then turn at a sharp angle and extend ten to twenty-five
feet in a horizontal or slightly upward course. The tunnel at the end
of the steep descending shaft is always more or less irregular in
course, and branches in various directions, the branches often ending,
in a rounded nest or storage chamber, but sometimes forming a loop back
to the main passageway. Not infrequently two entrances some distance
apart lead to these deep workings. A little niche is ingeniously dug
on one side of the steep entrance shaft, four to six feet below the
surface, to which on the approach of danger the owner retires to listen
and determine whether it may or may not be necessary to seek safety
in the depth of the den. It is from these vantage points that the
resentful voices of the habitants come to an intruder in a prairie-dog
“town” as he passes.
The black-tailed prairie-dog, which is so numerous on the Great Plains,
surrounds the entrance to its burrow with a crater-shaped pyramid
of soil varying from a few inches to nearly two feet in height and
serving perfectly as a dike to keep out the water. The owners keep the
funnel-shaped inner slopes of the rims about the entrances in good
condition by setting briskly to work to reshape them at the end of a
rain-storm, digging and pushing the earth in place with their feet and
molding it into a more compact mass by pressing it in with their blunt
noses.
The white-tailed prairie-dogs pile the dirt from their excavations out
on one side of the entrance, as in the case of most other burrowing
animals. Sometimes the dirt in these piles amounts to from ten to
twenty bushels, thus indicating extended underground workings.
The vivacity and hearty enjoyment of life by the occupants of a
prairie-dog “town” is most entertaining to an observer. With the first
peep of the sun above the horizon they are out on the mounds at the
entrances of their burrows, first sitting erect on their hind feet
and looking sharply about for any prowling enemy. If all is well they
begin to run about from one hole to another, as though to pass the
compliments of the day, and scatter through the adjacent grassy feeding
ground.
The favorite food of prairie-dogs consists of the stems and roots of
gramma grass and other richly nutritious forage plants. In addition
they eat any native fruits, such as that of the pear-leaved cactus
(_Opuntia_) and are extremely destructive to grain, alfalfa, and
other cultivated crops. In addition to ordinary vegetation, they eat
grasshoppers and are fond of flesh, sometimes being caught far from
their homes in traps set for carnivores. They keep the grass and other
vegetation cut down or entirely dug out over much of the “town” and
especially in a circle about each entrance mound, apparently for the
purpose of obtaining a clear view as a safeguard against the approach
of any of their many four-footed enemies. This habit is exceedingly
injurious to the cattle ranges and often results in much erosion of the
fertile surface soil.
[Illustration: PRAIRIE-DOG
_Cynomys ludovicianius_]
[Illustration: STRIPED GROUND SQUIRREL
_Citellus tridecemlineatus_]
The vast numbers of prairie-dogs over so large a part of the grazing
areas of the West take a heavy toll from the forage and other crops.
As a consequence a campaign of destruction is being waged against them
as the country becomes more and more settled, and they will eventually
disappear from much of their present range. However detrimental
they may be from an economic point of view, they are among our most
interesting species, and when taken young their playful disposition and
intelligence render them most entertaining captives.
[Illustration: CALIFORNIA GROUND SQUIRREL
_Citellus beecheyi_]
[Illustration: ANTELOPE CHIPMUNK
_Ammospermophilus leucurus_]
Owing to the constant danger to which they are subject from coyotes,
foxes, bobcats, badgers, and black-footed ferrets, in addition to
eagles and other birds of prey, prairie-dogs are constantly on the
alert. At any suspicious occurrence the first to observe it runs to
his entrance mound, if the danger is not pressing, but otherwise to
the nearest mound, where he sits up at his full height, “barking” and
vibrating his tail, ready, if necessary, to disappear instantly. At the
same time the “town” is alive with scurrying figures of the habitants
rushing panic-stricken for their homes, and the air is filled with a
chorus of their little barking cries. When all have been frightened to
cover barking continues in the burrows, but an hour or more may pass
before a “dog” will reappear.
I once stalked a solitary antelope by creeping flat on the ground
through a prairie-dog “town.” As I drew near the first burrows, the
“dogs” all rushed to their mounds, sitting there and barking at the
queer and unknown animal thus invading their precincts. The strange
sight excited as much curiosity among them as alarm. As I approached
one mound after another the owners would become almost hysterical in
their excitement and would sit first on all fours and then stand up
at full height on their hind feet, the tail all the time vibrating as
though worked by some mechanism, while the barking continued at the
intruder as rapidly and explosively as possible. When I came within
six or eight feet the “dog” would dive down his hole, sputtering barks
from the depths as he went, but often would pop up again to take
another look before finally disappearing. In this way I passed ten or a
dozen mounds while the dozens of “dogs” off my line of progress worked
themselves into a frenzy of curiosity and protest. When the stalk was
finished I passed back through the “town” and my upright figure was
promptly recognized by the habitants as that of an enemy and every one
disappeared before I was within fifty yards of the first mound.
The common note of the black-tailed prairie-dogs is a squeaking “bark,”
much like that produced by squeezing a toy dog; in addition, there is a
rapid chattering note, often given as the “dogs” vanish down the hole.
The white-tailed species have a shriller, more chirping note. In both
species the odd vibrating motion of the tail, held stiffly close to the
back, is characteristic.
Prairie-dogs hibernate in severe weather, those living in high,
snow-covered mountains or in the far north sometimes sleeping through
five or six months. In many places their hibernation is irregular, and
near the southern border of their range is limited to a few inclement
days now and then. In Wyoming they come out the last of March or early
in April, sometimes when there is a foot or two of snow on the ground
and the temperature ranges far below zero. Under such conditions they
run about over the snow during the middle of the day, feeding on
projecting tips of vegetation or digging to the ground.
Beginning near the southern border of their range and proceeding north,
the single litter of the season, containing from four to six young,
are born in March, April, or May, and a month later, when scarcely
larger than chipmunks, may be seen playing about the entrance mound.
When danger appears the mother sends the young helter-skelter for
the refuge of the burrow, and should any be slow about going in she
rushes at them, driving them to cover with shrill barks of alarm. When
about half-grown the young scatter and prepare burrows of their own.
Sometimes as many as six to nine of these animals may be found in a
single burrow, in which, no doubt, they have taken refuge, or it may be
a reunion of the season’s family.
On warm sunny days, especially at a time when nights are frosty,
these fat little animals will often lie flat on the bare ground about
their mounds, with legs outstretched, basking in the grateful rays.
As their colonies expand by the rapid increase of their numbers, many
individuals wander far in search of new locations. On the mountain
plateaus of northern Arizona I know of instances where they have
traversed several miles of pine and fir forest to locate in an isolated
mountain park, and new colonies were established as far as six miles
from their nearest neighbors.
The flesh of prairie-dogs is not unpalatable, and Navajo and Pueblo
Indians are extremely fond of it. The Indians take advantage of heavy
rains and turn the temporary rush of water down the holes to drown out
the “dogs,” and thus capture many of them.
It is inevitable that many popular misconceptions should grow up about
such numerous and interesting animals as the prairie-dogs. In the West
many people believe that the burrows go down to water. In reality,
like many other rodents, these animals have acquired the ability by
chemical action in the stomach to transform the starchy food into
water. I have seen dog towns located on a few feet of soil resting on
a waterless lava bed miles in extent and more than 100 feet thick, as
shown by canyons cut through it, thus proving the impossibility of the
prairie-dog-well legend.
Another popular belief is that the rattlesnakes and burrowing owls
living in prairie-dog towns unite as a kind of happy family in the
burrows of the dogs. The truth is that the owls live and breed in
deserted dog holes, while the rattlesnakes visit the occupied holes to
feed on the unfortunate occupants.
=THE STRIPED GROUND SQUIRREL= (=Citellus tridecemlineatus=
and its subspecies)
(_For illustration, see page 538_)
Small size and a series of thirteen narrow, well-defined stripes, or
lines, marking the upperparts of the striped ground squirrel serve to
distinguish it from all its relatives. Its total length is about eleven
inches and its form is nearly as slender as that of the weasel. Its
brightly colored markings blend so well with the brown earth and plant
stems in its haunts that when quiet it is difficult to distinguish.
This protective coloration is of vital service to a small animal
sought by all the diurnal birds of prey, as well as by coyotes, foxes,
bobcats, badgers, skunks, weasels, and snakes.
The striped ground squirrel, also known as the “gopher” or “striped
gopher,” is restricted to middle North America, where it is distributed
from southern Michigan and northern Indiana west to Utah, and from
about latitude 55 degrees in northern Alberta south nearly to the
Gulf coast of Texas. It ranges from near sea level in Texas up nearly
to 10,000 feet in Colorado. Within these limits the varying climatic
conditions have modified it into several geographic races, all having a
close general resemblance.
Like most members of the squirrel family, the striped ground squirrels
are diurnal in habits and well known wherever they occur. I first
learned the ways of these odd little mammals as a boy on the prairies
outside the city of Chicago, and later observed them in a high
mountain valley in Arizona. In both regions they had the same habits.
By preference they occupy grassy prairies, old fields, and similar
situations. In many areas they are serious pests, owing to their
abundance and their destructiveness to grain crops, but where the land
is generally cultivated, the sheltering vegetation and their shallow
burrows are destroyed by the plow, thus causing a decrease in their
numbers.
The lives of the striped ground squirrels are so beset with peril that
they always move abroad with watchful hesitation, pausing to listen,
retreating toward their burrows at the slightest suspicious sound or
movement, or rising bolt upright on their hind feet and remaining
motionless as a small statue until satisfied that there is nothing to
fear. They call to one another with a chirping note as well as with
a shrill trilling whistle, and when alarmed by the presence of some
enemy their warning call notes are heard on all sides as the alarm is
passed, and all are on the alert to disappear down their burrows at the
slightest suspicious movement.
When they have vanished their trilling notes are often heard from
the depths of their burrows; but curiosity is one of their strongest
traits, and if no disturbance follows one will almost immediately pop
up its head to see the cause of the alarm. Boys, taking advantage of
this habit, place an open slipping noose at the end of a long string
around the entrance of the burrow, and, waiting developments, lie
quietly a few yards to one side. The ensuing silence is too much for
the ground squirrel to endure and soon its head appears above ground,
the boy pulls the string, and the victim is dragged forth with the
noose about its neck.
The entrance to the burrow of these ground squirrels is about two
inches in diameter. It is usually located in the midst of grass or
weedy growths, and has little or no fresh earth about it. The burrow
descends for several inches almost vertically and then turns almost
horizontally in a sinuous and erratic course, with numerous branches
and side passages leading up to the surface. Most of these side
entrances are kept plugged with soft earth. Opening off the main tunnel
is a large nest chamber filled with fine dry grasses and other soft
vegetable matter, and also one or more large storage chambers in which
the owner lays up his garnered supplies of grain or other seeds for use
during inclement weather.
These squirrels hibernate throughout their range, entering their long
sleep in an excessively fat condition the last of September or in
October. In the North they remain in a torpid state for six months or
more.
Soon after they appear in spring they mate and the single litter of
the year, containing from five to thirteen young, is born the last of
May or early in June. The young are in an extremely undeveloped state
at birth, being blind, hairless, and with the ears scarcely showing.
They develop slowly and remain with the mother until toward fall, when,
nearly grown, they scatter to care for themselves.
The striped ground squirrels are among the most carnivorous of rodents.
Although they devote much time to gathering grain, seeds of various
kinds, and even acorns and other nuts, which may be eaten on the spot
or carried in their cheek pouches to their underground storage rooms,
in addition they are known to eat insects and flesh whenever occasion
offers. In fact, during seasons when such insect food as grasshoppers,
caterpillars, and grubs is plentiful, these ground squirrels frequently
feed mainly upon it. They are known to kill and devour mice and young
birds, and when confined in a cage will sometimes kill and partly
devour their own kind. When caught they fight fiercely, biting and
struggling to escape. In captivity they show little of the gentleness
and intelligence which are such pleasing characteristics of chipmunks
and true squirrels.
=THE CALIFORNIA GROUND SQUIRREL= (=Citellus beecheyi= and its
relatives)
(_For illustration, see page 539_)
Owing to its habits, the California ground squirrel is known locally as
the digger-, rock-, or ground-squirrel. Its prominent ears, bushy tail,
color, and form give it the general appearance of a heavy-bodied gray
tree squirrel, but in reality it is a true, spermophile and close kin
to the marmots.
[Illustration: GOLDEN CHIPMUNK
_Callospermophilus lateralis chrysodeirus_]
[Illustration: EASTERN CHIPMUNK
_Tamias striatus_]
Spermophiles are nearly circumpolar in distribution, ranging through
northern lands from central Europe across Bering Strait to the Great
Lakes in North America. Many species exist in North America, varying
greatly in form, size, and color. They occur mainly in the western
part of the continent from the Arctic coast of Alaska to the southern
end of the Mexican table-land. Some species are represented by enormous
numbers and do great injury to cultivated crops. Among the larger and
best known of the injurious species, the California ground squirrel,
with its several geographic races, occupies most of the Pacific coast
region from Oregon to Lower California. It has a broad vertical
distribution, extending from the seashore to about 10,000 feet altitude
on the western slope of the Sierra Nevada in California, and thrives
under contrasting climatic conditions, as the humid northwest coast
region and the most arid deserts of Lower California.
[Illustration: OREGON CHIPMUNK
_Eutamias townsendi_]
[Illustration: PAINTED CHIPMUNK
_Eutamias minimus pictus_]
In California, where they are generally distributed and extremely
numerous over great areas, these ground squirrels are most at home
among the wild oats and scattered live oaks on the open slopes of the
rocky foothills and thence up through the dense chaparral, scrub oaks,
piñon pines, and junipers. Above this they populate many beautiful
little valleys in colonies, as well as parts of the splendid open
forests of pine and fir. Below they spread out from the foothills among
the ranches in the great valleys. Wherever they occur they take heavy
toll from the native forage plants, and in cultivated areas their
devastations of crops place these spermophiles among the most serious
of mammal pests.
They are omnivorous, eating insects and flesh on occasion, but
feeding mainly on seeds, fruits, and many kinds of plants. The native
vegetation in their haunts contains a wonderful variety of food plants,
from humble weeds in the valleys to the lordly pines of the Sierra,
but most attractive to these rodents are the rich food-bearers brought
by the cultivators of the soil. The squirrels gather in great numbers
about farms, and in feeding upon alfalfa, wheat, and other grains,
grapes, peaches, apricots, almonds, prunes, pomegranates, and a variety
of other crops, cause an annual loss to the farmers of California
probably exceeding $20,000,000. So serious are their depredations that
great sums have been spent in attempts to destroy them with poison. The
Kern County Land Company, with vast holdings in the southern end of the
San Joaquin Valley, in 1911 spent more than $40,000 for this purpose.
This company estimated that the ground squirrels destroyed 20 per cent
of the grain crop in great areas, and that twenty of them would destroy
enough forage to support a cow through the year.
Ground squirrels by choice locate their burrows among slide rock, in
crevices among cliffs, under boulders and roots of trees, in ditch or
dry creek banks, or under stone walls, fences, or building, but in the
parks of the high Sierra, as in the foothills and lowland valleys, they
dig holes out in the open with conspicuous mounds at the entrances much
like those of prairie-dogs.
Well-worn trails lead from one of their burrows to another and away to
a distance through the wild oats in the foothills, or in the grain
and forage crops of the valleys, and along these the animals travel
when foraging or paying social visits. Whenever a large rock, stump,
or other prominent object is convenient, they spend hours on the top
sunning themselves and keeping a sharp lookout over their surroundings.
From these lookout points when they suspect danger they utter a short,
shrill, whistling note which may be heard at a long distance and which
sends all their neighbors scurrying for shelter. They also have a lower
chattering note, uttered about the burrow when resenting an intrusion
or when otherwise displeased.
Ground squirrels are agile climbers on cliffs and among rocks as well
as in fruit trees, live oaks, and other low trees, but I have never
seen them far from the ground in large trees. When on the ground they
run in a series of bounds like tree squirrels. The long, bushy tail is
carried almost straight out behind when they scamper off in alarm, but
at other times is curved and undulating, much as in the tree squirrels.
They gather and manipulate food with their front paws, sitting upright
on their haunches to eat or look about. On one occasion when I came to
a foot-bridge over a broad irrigating ditch across which a number of
ground squirrels were raiding an orchard, they did not hesitate to dash
at full speed into the swiftly running water and swam quickly across to
seek refuge in their holes on the far side.
Like other spermophiles, the California ground squirrels hibernate
for months in the cold, snow-covered parts of their winter range, but
remain active throughout the year in the warmer areas, where no snow
falls. Throughout their range they gather stores of seeds, grain,
and acorns and other nuts, carrying them in their cheek pouches to
underground store-rooms for use in bad weather. In the valleys of
California they lie hidden in their burrows for days at a time during
cold winter rains, but are out as soon as the sun reappears. One or
more litters, each containing from six to twelve young, are born from
March to late in summer, according to the locality. The young leave the
nest and care for themselves when about half grown.
The swarming abundance of the California ground squirrel on foothill
slopes and in fertile valley bottoms equals the congregations of
prairie-dogs in their most populous districts. This abundance of small
animal life supports a great variety of predatory species, as coyotes,
foxes, bobcats, several kinds of hawks, and the golden eagle. Owing to
its predilection for ground squirrels, the golden eagle is protected
by law in California, where many of them build their nests in low live
oaks only a few yards from the ground.
When house rats brought the bubonic plague to San Francisco a few years
ago they also carried it across the bay and passed it on to the ground
squirrels living in the foothills back of Oakland. Thence the disease
spread among these animals through parts of several surrounding
counties. The United States Public Health Service and the local
authorities in a vigorous campaign stopped the spread of this malady,
but not until the potential ability of these rodents as plague-carriers
had been well established. This fact and the wide distribution of
the California and other ground squirrels over a large part of the
continent should not be overlooked in connection with possible
future outbreaks of the plague. Fortunately, investigation and field
experiments on a large scale have shown that these spermophiles may be
destroyed by poison over great areas at a relatively small cost.
=THE ANTELOPE CHIPMUNK= (=Ammospermophilus leucurus= and its
relatives)
(_For illustration, see page 539_)
Commonly known as the antelope, or white-tailed, chipmunk, this
handsome little mammal is in reality a species of spermophile, or
ground squirrel. The misnomer is due, no doubt, to its small size,
striped back, and sprightly ways. From the true chipmunks it may be
distinguished by its heavier proportions, and from both chipmunks and
all other spermophiles by its odd, upturned tail, carried closely
recurved along the top of the rump. This character renders the species
unmistakable at a glance and gives it an amusing air of jaunty
self-confidence.
The antelope chipmunk is characteristic of the arid plains and lower
mountain slopes of the Southwest from western Colorado through Utah,
northern Arizona, Nevada, the southern half of California, and all of
Lower California, and down the Rio Grande Valley through New Mexico to
western Texas.
Within this area it occupies a wide variety of situations. It inhabits
the intensely hot desert plains near sea level in Lower California,
where the temperature rises to more than 125 degrees Fahrenheit in the
shade and the vegetation is characterized by such picturesque forms
of plant life as cactuses of many species, yuccas, fouquerias, palo
verdes, ironwood, and creosote bushes; it is found also above 7,000
feet altitude on the cool plateaus and mountain slopes of Arizona and
Colorado, among sage brush, greasewood, junipers, and piñon pines. It
appears equally at home skipping nimbly over rocky slopes or among
slide rock in arid canyons and scurrying through the brushy growth on
broad sandy plains devoid of rocks.
The antelope chipmunk has the most vivacious and pleasing personality
of all the numerous ground squirrels within our borders. During the
many months I have camped and traveled on horseback in their haunts I
have never lost interest in them. They were forever skirmishing among
the bushes or dashing away down trails or over the rocks of canyon
slopes, their white tails curled impudently over their backs like flags
of derision at my cumbersome advance.
Their burrows are dug in a variety of places. In the open flats they
enter the ground almost vertically, and often several entrances are
grouped within a few yards. In some places a little mound of loose
dirt is heaped up at one side of the entrance and at others there is
no trace of it. Frequently, when the ground is soft, little trails
lead in different directions from the entrances, and often between
holes 100 yards or more apart, as though they made many social visits.
The deserted burrows of other mammals are sometimes utilized to save
the trouble of digging. The burrows are often under the shelter of
cactuses, bushes, and great boulders or may be among crevices in the
rocks.
Antelope chipmunks are extraordinarily active and continually wander
far from home in search of food or in a spirit of restless inquiry. As
the traveler on horseback rides slowly along he will see them racing
away in front of him, sometimes climbing to the top of a bush 100
or 200 yards in advance for a better look at the wayfarer and then
scuttling down and racing on again. In this way I have seen them keep
ahead of me sometimes for several hundred yards instead of hiding in
some hole or shelter, as they might easily do. At other times they were
so unsuspicious they would permit me to pass within a few yards with
slight signs of alarm. They have a chirping call, often uttered when
watching from the top of a bush, and also a prolonged twittering or
trilling note, diminishing toward the end.
In the higher and colder parts of their range, where snow lies long on
the ground, these spermophiles hibernate for several months, but in the
warmer areas they are active throughout the year. Wherever they occur
they gather food and carry it to their underground store-rooms in their
cheek pouches. Like most ground squirrels, they eat many kinds of seeds
and fruits as well as flesh and insects when occasion offers. About
cultivated lands they are sometimes abundant and destructive, digging
up corn or other grain as soon as it is planted and also taking toll of
the ripening grain until they become a pest. In the desert they often
gather about camps to pick up the grain scattered about when the horses
are fed.
It is well for them that they are prolific, having one or more litters
during spring and summer, with from four to twelve in each, as they
have many enemies. Snakes and weasels pursue them into their burrows,
while foxes, coyotes, badgers, bobcats, and many kinds of hawks,
constantly reduce their numbers.
=THE GOLDEN CHIPMUNK= (=Callospermophilus lateralis
chrysodeirus= and its relatives)
(_For illustration, see page 542_)
[Illustration: RED SQUIRREL
_Sciurus hudsonicus_]
[Illustration: DOUGLAS SQUIRREL
_Sciurus douglasi_]
The golden chipmunk, or calico squirrel, as it is named in Oregon, is
the most richly colored of the several geographic races of a widely
known species, _Callospermophilus lateralis_, abundant among the open
forests of yellow pines and firs of the western ranges, including
the Rocky Mountains, Cascades, and Sierra Nevada. Although commonly
known as a chipmunk, this handsome animal is a ground squirrel,
or spermophile, distinguished from all its kind by heavy stripes,
resembling those of a chipmunk, along the sides of its back. From the
chipmunks it may be distinguished at a glance by its thick-set and
often almost obese proportions, which render its movements much slower
and less graceful than they are with those nimble sprites. It occurs
from northeastern British Columbia to New Mexico, southern California,
and even in an area in the high Sierra Madre of southern Chihuahua,
where an isolated representative occupies a limited range.
[Illustration: GRAY SQUIRREL (and black phase)
_Sciurus carolinensis_]
[Illustration: RUSTY FOX SQUIRREL
_Sciurus niger rufiventer_