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Class MAMMALIA: Vertebrate Animals
That Nurse Their Young
[p.43]
Order RODENTIA: Gnawing Animals
Family SCIURIDAE: Squirrels, Chipmunks,
Prairie Dogs, Ground Squirrels, and Marmots
Glaucomys sabrinus canescens
Howell
Pale Flying Squirrel
Glaucomys sabrinus canescens
Howell, Proc. Biol. Soc. Washington, vol. 28, p. 111,
1915.
Type locality.--Portage
la Prairie, Manitoba.
General characters.--About
twice the size of the little southern species.8
Wide membranes connecting the front and hind legs along
each side when spread form a monoplane which enables the
animal to soar or glide from tree to tree. Tail, wide
and flat; fur, very soft and silky, of a delicate cinnamon-brown
color over upper parts, creamy white below. Average measurements
of adults: Total length, 297 millimeters; tail, 138; hind
foot, 37 or 38.
Distribution and habitat.--The
pale flying squirrel, a big northern member of the family,
comes into eastern North Dakota along [p.44]
the timber of the Red River Valley and up some of the
streams to the west. Specimens have been examined from
Pembina, Grafton, Portland, Grand Forks, and Fargo. These
squirrels are common throughout the forest areas of the
Pembina Hills and probably occur in the Turtle Mountains,
although no definite records have been obtained. At Portland,
in 1895, J. A. Loring caught one in a meat-baited trap
set under a log in an oak grove. At Grafton, in 1915,
Remington Kellogg reported several taken during the preceding
winter when the timber was being cleared from some bottomland,
but he was unable to obtain any specimens. He found one
in the collection of H. V. Williams, which was examined
later by Howell (1918) for identification while preparing
his revision of the flying squirrels. At Manvel, in the
eastern part of Grand Forks County, he reported a family
of flying squirrels including a nest and six young, found
by a farmer, William Brown, the preceding year; the nest
was made of bark fibers and placed in the fork of an elm
tree, but when Kellogg examined it it was empty. W. B.
Bell told the writer of a family of flying squirrels found
by a boy in the woods at Fargo, in 1912.
General habits.--Owing
to their strictly nocturnal habits flying squirrels are
rarely seen although they are much more common than is
supposed. In a wide range over the northern timbered country
wood choppers and lumbermen frequently see them leaving
the hollow of some falling tree and soaring on widespread
membranes to a neighboring trunk, or sometimes, in their
confusion, to the ground from which they quickly seek
the nearest tree. Usually their nests are within the hollow
cavities of tree trunks, sometimes in hollow limbs, knotholes,
or the old nest cavities of woodpeckers. Occasionally
nests of moss and bark fibers are built among the branches,
much like those of the red squirrel. Where the little
animals are common it is not difficult to frighten them
out of their nests by pounding the hollow trees with an
ax. A few smart raps on the base of their trees will usually
induce them to peer out of their nests, and continuous
pounding will often alarm them into making long flights
to neighboring trees. Often one will run to the top of
its tree to get a good start and, sailing downward until
momentum is gained, go coasting off 50 or 75 feet and,
curving gracefully upward to check its speed, strike lightly
on the trunk of another tree much lower down than where
it started. By running up each tree and soaring downward
to the next, the squirrels pass rapidly through the woods
until some safe retreat is found.
They are soft, silent,
owl-like animals and in the daytime seem sleepy and sluggish.
At night their presence is mainly shown by their getting
into traps set for fur animals and by their tracks on
the snow between trees whose span is too great to be bridged
by their soaring flight. Little is known, however, of
their real habits except that they make interesting and
often mischievous pets, are easily tamed, and become playful
and affectionate, but insist on sleeping through the day
and carrying on most of their activities at night. They
are frequently preyed upon by cats and owls, which occasionally
leave their tails uneaten to mark the place of a nocturnal
meal.
Food.--A great part
of the food of flying squirrels consists of nuts and seeds
of trees, shrubs, and vines. At Moorhead, in 1908, Murie
[p.45] watched several of them by moonlight
feeding on the seeds of ash trees. He says: "They sailed
about from tree to tree, stopping occasionally to eat
some seeds. Several times I saw one turn a little in its
flight and they turned up a little just before landing
on a tree trunk." The woods where they occur are usually
well supplied with acorns, basswood, boxelder, ash, elm,
hackberry, ironwood, birch, and alder seeds and a great
variety of berries, grapes, and other seeds, fruits, and
buds that remain all winter and are easily obtained, so
that generally these animals do not lay up stores of food.
They are more omnivorous than most squirrels and will
readily take bread, oatmeal, fruit, or meat used for trap
bait, and closely related varieties are often caught in
marten or weasel traps baited with meat, fur, or feathers.
Economic status.--Though
rarely of sufficient abundance to be of economic importance,
flying squirrels are, so far as known, practically harmless.
Crops and cultivated fruits are rarely if ever disturbed
by them and the tree seeds they consume are doubtless
well paid for in the scattering and wider planting of
those not eaten. As pets for children few animals are
more gentle and attractive.
Sciurus carolinensis hypophaeus
Merriam
Minnesota Gray Squirrel; Black Squirrel
Sciurus carolinensis hypophaeus
Merriam, Science, vol. 7, p. 351, 1880.
Type locality.--Elk
River, Minn.
General characters.--Larger
and darker colored than the Carolina gray squirrel, with
little or no white on the underparts. Color, generally
dark gray, often becoming dusky or black. Tail, large
and bushy. Average measurements of adult specimens: Total
length, 496 millimeters; tail, 220; hind foot, 67. Weight
of adult female, 14 ounces (Murie).
Distribution and habitat.--The
large Minnesota gray tree squirrels barely come into the
southeastern part of North Dakota along some of the timbered
stream valleys, although they are abundant throughout
the oak region of Minnesota. At Wahpeton, in 1915, an
old resident said that he had killed one there 18 years
before, but had never seen one since. Later, some squirrels
had been brought from Minnesota and placed in a grove
on the Dakota side of the river, but they were not protected
and all were killed. At Fargo and Moorhead, O. J. Murie
remembers them as long ago as 1906, and thinks they have
always been there. Since 1910, they have been increasing
and in 1919 were common on both sides of the river, and
especially in the extensive and beautiful parks just south
and north of Fargo, where an abundance of old hollow trees,
oak, basswood, elm, and ash, furnish safe homes and choice
food. At Valley City, in 1912, Eastgate reported them
as introduced in the city parks and slowly increasing.
In Minnesota their northern limit seems to be in the vicinity
of Crookston, and it would be strange if they did not
occasionally extend into the Red River Valley in the neighborhood
of Grand Forks. Records, however, are wanting north of
Fargo.
General habits.--Besides
being good game animals, these large, handsome squirrels
are one of the popular attractions of city parks and protected
grounds, where they readily become familiar and, with
a little care, very tame. Constant hunting keeps them
extremely [p.46] shy and secretive in
their wild state; but, for rodents, they show a high order
of intelligence and quickly learn the protected areas,
eagerly responding to friendly advances in the way of
food, water, and nest boxes. In their native habitat their
food consists very largely of acorns from the numerous
species of oaks with which they are associated, but it
also includes nuts and seeds of many other plants. For
a successful introduction into parks or private grounds
they must he supplied with acorns, nuts, or grain.
Their winter homes are
usually in the hollow trunks of trees, where in well-protected
and warm nests of bark and plant fibers they pass the
coldest winter weather in comfort. In summer they build
large nests of leaves in the branches of the trees, covering
them over to form comfortable, rain-proof houses, with
nest cavities in the center, which they enter through
half-concealed side doors. In some cases the houses are
made large and warm for occupation throughout the winter,
but usually a hollow trunk or warm box is preferred for
a winter residence.
The interest and delight
of children in watching the squirrels, which in parks
and private grounds become so tame that they will come
to the hand and beg for nuts gives them a value far greater
than that of game and fully repays the effort to provide
them with comfortable quarters and to plant such trees
as will insure their permanent food supply.
Sciurus hudsonicus hudsonicus Erxleben
Red Squirrel; Chickaree
Ahjiduhmo of the Ojibways
(Wilson)
[Sciurus vulgaris] hudsonicus
Erxleben, Syst. Regni Anim., p. 416, 1777.
Type locality.--Hudson
Strait.
General characters.--About
half the size of the gray squirrel, with full bushy tail
and a general reddish or rusty color over the upper parts;
a black line along each side in summer borders the white
underparts, which in fall is lost in the reddish-gray
winter coat. Average measurements: Total length, 340 millimeters;
tail, 140; hind foot, 50. Weight, 8½ to 9 ounces
(Murie).
Distribution and habitat.--The
sprightly little red tree squirrels are generally abundant
in the timbered areas along the Red River Valley from
Wahpeton to Pembina and along all of the streams which
carry lines of timber into the prairie country west of
the valley; also in the Pembina Hills and Turtle Mountains
as far west as the Mouse River and upper timbered strips
of the Sheyenne River near Stump Lake. In 1887 they were
common near Fargo, Grand Forks, and Pembina, and in the
Turtle Mountains. In 1912, there were said to be a small
number in the timber around Lake Elsie, near Hankinson,
in the extreme southeastern corner of the State, though
they had been mostly killed off there. At Portland, in
1892, J. Alden Loring took a specimen, and reported them
as common in the groves along the Goose River. In 1893,
A. K. Fisher saw one in the timber along the Sheyenne
River near Lisbon. In 1912 Eastgate reported a few along
the Sheyenne River 3 miles south of Tolna. At Valley City
he reported them as very common all along the river in
the timber and occasionally in the larger groves around
farm buildings on the prairie close to the river valley,
[p.47] and at Lisbon, farther down the
river, he said they were common in patches of woods sufficiently
large to afford them suitable homes; often two or more
pairs were found in a single grove, and from his tent
in one of these groves he was able to see three occupied
nests at one time. At Fargo they were still common in
the timber along the Red and Sheyenne Rivers. Kellogg,
in 1915, found them in good numbers at Grand Forks, Grafton,
and Pembina; near Towner, in the timber along Mouse River,
he reported them fairly common and saw many of their nests
in the branches of the trees.
General habits.--In
June, 1912, while camping near the fish hatchery in the
eastern part of the Turtle Mountains, the writer found
red squirrels common throughout the timber, as they apparently
are throughout the Turtle Mountains and Pembina Hills.
At that season, when the females taken for specimens were
still nursing young, they were quiet and keeping out of
sight as much as possible. Only once was a subdued barking
heard. They live mainly in hollow trees, but a few nests
of grass and bark fibers were found in the branches of
the trees, and in places the squirrels apparently were
occupying burrows and hollow spaces in old stumps and
logs. As soon as the young are safely out of the nest
and able to care for themselves the squirrels become noisy
and for the rest of the year their sprightly chatter and
scolding is heard throughout the forest.
Their food consists of
acorns, nuts, seeds, mushrooms, and occasionally birds'
eggs. Their omnivorous tastes are strikingly different
from those of the gray squirrel, and for this reason they
have incurred the enmity of those who appreciate the value
and beauty of birds as well as of squirrels, and also
those who have unprotected corncribs or grain bins to
which squirrels may gain access. It is often necessary
to reduce the numbers of these cheerful little marauders
for the protection of birds and crops, but where they
are not doing serious damage they are among the brightest
and most attractive forms of wild life either in the forest
or in parks and private grounds. In winter, although they
spend much of the time within their warm nest hollows,
they are active even during the coldest weather, visiting
their food caches, to which they gain access by endless
tunnels in the deep snow. One of the cheeriest sounds
of the forest on a bright winter's day is the long chr-r-r-r-r-r
from the feeding branch of one of these squirrels as he
cracks a hazelnut or eats an acorn above the glistening
field of snow.
Eutamias minimus borealis (Allen)
Little Northern Chipmunk
(Pl. 10)
Tamias asiaticus borealis Allen,
Monogr., North Amer. Rodentia, p. 793, 1877.
Type locality.--Fort
Liard, Mackenzie, Canada.
General characters.--Readily
distinguished from the larger gray chipmunks, with which
often associated, by the series of fine longitudinal light
and dark stripes extending over the back from head to
tail, by their slender build, long slender tails and pointed
ears, and by the generic character of five molars in each
upper tooth row. A specimen from the Turtle Mountains
measures in total length, 223 millimeters; tail, 106;
hind foot, 33. Weight of adult female, 52.6 grams.
Distribution and habitat.--The
little northern chipmunks are abundant throughout the
forested and brushy areas of the Turtle [p.48]
Mountains and Pembina Hills, and they have been reported
in the forest along the Mouse River near Towner (fig.
1). H. V. Williams in 1912, reported them abundant in
the Pembina Hills throughout the timbered parts, where
they lived in underbrush and around brush piles, old stumps,
and fallen trees. They were very tame, but when alarmed
always sought protection in their ground burrows rather
than in the trees.
General habits.--in
all parts of the Turtle Mountains the writer found them
more or less common and often very tame and unsuspicious,
although nervous and quick to take alarm. Their fine rapid
chuck-chuck-chuck notes are usually the first indication
of their presence. It is often difficult to locate them
by their voices, which are more or less ventriloquial,
but by moving cautiously one can usually find a chipmunk
perched on the branch of a bush, on a brush heap, or on
a stump or log close to its underground home. In a dense
thicket careful search is often necessary to locate the
voice, but if it does not vanish with a sharp chipper,
one may find the little striped gray-coat perched half
way up a willow or aspen bush, chirping and waving its
tail. To the casual observer its actions may indicate
mere curiosity, but its curiosity is far from idle. It
involves parental care, mutual protection, watching for
enemies, and warning of danger. Although restless sprites,
disappearing like a flash and quickly reappearing, at
times they will sit quietly for some minutes, calling
in a monotonous churp-churp-churp, much like the
cry of a robin in distress. If an enemy approaches the
note often changes to a more rapid quit-quit-quit
suggesting the note of the ruffed grouse when about to
take wing. When suddenly frightened they run with a rapid
twitter, which at times becomes frantic in their haste
to get to cover.
[p.49]
in the Turtle Mountains in August, 1887, northern chipmunks
were found feeding extensively on the seeds of chokecherries,
the shelled kernels of which were stuffed in their cheek
pouches, evidently to be stored for winter food. Acorns
and various seeds also were found in their pockets. Their
feeding grounds show traces of many seeds and berries
that have been eaten. They are said to do some mischief
in gardens and along the edges of grainfields, but nowhere
were they found a serious pest.
In the Pembina Hills in
1919 up to October, they were busily storing seeds and
grain. They were often seen with cheek pouches distended,
running for their storehouses in underground cavities,
where evidently enough food was being laid up to carry
them through the winter, for they showed no signs of becoming
fat or preparing for hibernation.
| FIG. 1.--Records of three species
of chipmunks in North Dakota: Squares, Gray chipmunk;
triangles, little northern chipmunk; circles, pale
chipmunk |
Eutamias minimus pallidus (Allen)
Pale Chipmunk
(Pl. 10)
| Sachho of the Arikaras (Gilmore);
Hetkadan
of the Dakotas (Gilmore); Hinudek of the
Mandans (Gilmore); Kokokshi of the Hidatsas
(Gilmore). |
Tamias quadrivitatus var. pallidus
Allen, Proc. Boston Soc. Nat. Hist., vol. 16, p. 289,
1874.
Type locality.--Camp
Thorne, near Glendive, Mont.
General characters.--Differs
from borealis mainly in lighter coloration, which
goes with the more open and arid habitat; the brown tones
are more yellowish, the gray lighter, and the white markings
more extensive. Adult specimens average in total length,
206 millimeters; tail, 91; hind foot, 31. A male of the
year taken October 15 at Sanish measured 200, 90, and
30 millimeters, respectively, and weighed 38 grams.
Distribution and habitat.--The
sagebrush Badlands country along the Missouri River and
westward is the home of the little pale chipmunk. (Fig.
1.) Specimens have been taken at Wade and Parkin on the
Cannonball River, Palace Buttes, 6 miles north of Cannon
Ball, near Sanish, Williston, Buford, Oakdale, Quinion,
Medora, Sentinel Buttes, the former Dakota National Forest,
and Marmarth. A little below Williston and near Grinnell
and Elbowoods a few are found on the north side of the
Missouri River, but generally they are restricted to the
country south and west of the river. In 1833, Maximilian
(Wied, 1839-1841, Bd. 2, p. 49, 1841) wrote of them: "A
few miles below the mouth of the Muddy River, these pretty
little four-striped squirrels are in great numbers running
along the ground and up the trees with the fruit of rosebushes
in their mouths." In 1843, Audubon (1897, p. 27) reported
them in the very same place, running over the ground.
In 1913, in company with W. B. Bell, the writer crossed
the river at this point and was greatly interested to
find the chipmunks still there in the brush and timber
on both sides of the river. In 1910 H. E. Anthony collected
a series at Fort Buford and found them common also on
the south side of the river. Near the Sioux Crossing,
6 miles southeast of Buford, he found them abundant along
brushy banks and coulées and about ranches where
there were woodpiles or old buildings near the banks of
ravines on the south side of the river. Some were also
found in [p.50] the heavy brush, but
apparently they are partial to the more open country.
In 1915 Remington Kellogg, on his way down the river from
Williston to Bismarck, reported them very common near
Grinnell, in Williams County, both in the Badlands and
in the brush along Beaver Creek, where several were taken.
At Goodall, in McKenzie County, they were very common
along creeks, rivers, and in the Badlands. Others were
seen along the river on the way down to Elbowoods, where
they were most abundant on the west side. Near Expansion
in Mercer County, a few were found in the willows, and
at Stanton a pair was seen in a buffaloberry bush eating
the ripe fruit. They are said to occur at Mandan, and
Russell Reid says that he has seen them on the east side
of the river at Bismarck. In 1913 Jewett found them in
the Badlands and gulches about Medora, near Quinion, and
also in the Killdeer Mountains. At Sentinel Butte he collected
two specimens among the rocks of the large buttes south
of town, and they were found common both along the gulches
about the Little Missouri south of Sentinel Butte and
on the Dakota National Forest. At Marmarth, in the southwestern
corner of the State, they were found common in 1909, over
the brushy sides of the Badlands buttes.
General habits.--The
little Badlands chipmunks are skilful climbers, but as
they generally live in thickets and sagebrush their climbing
is mainly through the branches of these dwarf trees and
is largely done in search of food or to get high enough
above the ground to watch for their enemies. Their real
homes are in the ground or in cracks and crevices of cliffs
or Badlands banks, to which they dart when alarmed. They
are often seen running over the sides of banks and bare
walls, from one brush patch to another, or from their
dens to the patches of brush and weeds which furnish food
and shelter. When alarmed they run with such speed even
over the roughest ground that pursuit is useless, and
the collector in search of specimens must use much patience
and skill to secure them. At other times they are so sure
of their safe retreats that they come out boldly to satisfy
their curiosity and are easily collected at close range.
Their voice is similar
to that of many other species of small chipmunks, but
very fine and light. It varies from the slow chip-chip-chip
as one sits confidently near a safe retreat, to the much
more rapid chipper of alarm as it flies for cover. At
times this chipper is heard from the top of a bowlder,
the point of a clay bank, or from a branch of bullberry
or other bush.
These chipmunks eat a great
variety of seeds and berries and a little green vegetation.
They seem particularly fond of the bullberries, which
in fall load the bushes with masses of scarlet fruit.
The seeds of these berries are removed and either eaten
on the spot or carried away for winter stores. Serviceberries
are also a favorite food. The chipmunks eat the outer
pulp of the rose haws as well as the hard seeds within
and are fond of the flesh and seeds of the little wild
currants and purple gooseberries. Their cheek pouches
often contain the seeds of various grasses, sedges, and
numerous other plants, which are carried away to be eaten
at leisure or stored up for winter use. In the Killdeer
Mountains Jewett says that acorns and hazelnuts furnish
them with a choice supply of food.
[p.51]
Economic status.--In places the Badlands chipmunks
become very numerous around the edges of gardens and fields,
where they do some mischief to growing crops. Anthony
says that at one ranch near Buford they became so troublesome
that the owner was forced to shoot them, killing 26 in
one afternoon. They are easily trapped or poisoned, however,
when it is necessary to thin them out, and by a little
care their mischief can be controlled.
Tamias striatus griseus Mearns
Gray Chipmunk
(Pl. 10)
Tamias striatus griseus Mearns,
Bul. Amer. Mus. Nat. Hist., vol. 3 (1890-91), p. 231,
1891.
Type locality.--Fort
Snelling, Minn.
General characters.--Large
and heavily built, with broad stripes on the back; readily
distinguished from the two species of small chipmunks
by larger size, heavier build, more phlegmatic dispositions,
more reddish-brown in the colors of the upper parts, and
by the generic character of only four molars in each upper
tooth row. Average measurements: Total length, 260 millimeters;
tail, 95; hind foot, 87. An adult female weighed 3¾
ounces.
Distribution and habitat.--The
grayish race of the large rusty-brown chipmunk is common
in the timber all along the Red River Valley from Wahpeton
to Pembina, and westward along the timbered valleys as
far as Lisbon, Kathryn, Portland, Larimore, Grafton, and
throughout the Pembina Hills and Turtle Mountains (fig.
1). Apparently they do not reach the timbered area of
the Devils Lake region. They are restricted entirely to
timbered and brushy areas, where they live in hollow logs,
stumps, trees, and underground burrows.
General habits.--The
gray chipmunks climb trees readily, but are more often
seen running over the ground, logs, stumps, or fences.
Their summer nests are usually placed in hollow logs or
trees, but their winter homes and food stores are mainly
in burrows underground. These burrows are also used throughout
the summer as safe retreats and for storing winter food
supplies.
The chipmunks are occupied
through the spring and early summer with their family
cares, and as soon as the half-grown young are out of
the nests in June, the search for food, and a little later
the storing of a winter's supply of nuts, seeds and grain
fill the daylight hours. Soon after frosty nights begin
late in September, they enter their winter burrows, where
they remain buried under the snow until the following
March or April. The four to six young are born about the
first of May. During the breeding season they are very
quiet and shy, keeping as much as possible out of sight,
but later a slow chuck-chuck-chuck is often heard
from the woods and thickets, or a shrill chipper of alarm,
as the startled animals rush for the nearest cover or
up the trunk of some friendly tree.
Their food includes a great
variety of nuts, seeds, grains, berries, and some green
vegetation, as well as occasional insects, frogs, and
lizards. Acorns and hazelnuts are the favorite winter
stores and often are deposited in cavities near the nest
chambers, a quart or more in a place. Just when these
food stores are used is not well known; they may furnish
an occasional meal throughout the winter, [p.52]
or tide over the drowsy period of entering upon and emerging
from hibernation, or carry the chipmunks through the spring,
when the ground is still frozen and wet and food scarce,
or even through the breeding period. It is improbable
that the stores are used up before spring, as hibernation
seems to be complete and considerable fat is laid up inside
the skins of the animals to carry them through the winter.
Economic status.--In
places where they are abundant chipmunks sometimes do
serious mischief along the edges of fields, digging up
the planted corn in spring and harvesting more than their
share of the ripe grain later on. Many of the missing
hills of corn along the edge of a brush-bordered field
are due to the fact that these little squirrels have carried
away the seed just when it was sprouting or earlier. Where
their mischief becomes serious it is easily checked by
scattering poisoned grain along the fences and under the
logs were they run.
Citellus tridecemlineatus tridecemlineatus
(Mitchill)
Striped Ground Squirrel; Thirteen-lined Ground Squirrel;
Leopard Squirrel
| Tashnáheca of the Dakotas;
Tshísh-karani of the Arikaras; Naksátshi
of the Hidatsas; Mashedónikcha of
the Mandans (all, Gilmore). |
Sciurus tridecem-lineatus Mitchill,
Med. Repos., vol. 21 (n. s., vol 6), p. 248, 1821.
Type locality.--Central
Minnesota.
General characters.--Short
ears, slender body and tail, seven dark-brown and six
narrow buff lines on the back, and buffy underparts. The
brown stripes are dotted and these distinguish it from
chipmunks and all the other striped squirrels. A rather
large specimen from Fargo measures in total length, 300
millimeters; tail, 115; hind foot, 39.
Distribution and habitat.--The
striped, or thirteen-lined ground squirrel, with its paler
western form, covers the whole of North Dakota, and most
of the specimens east of the Missouri River are referable
to the typical dark form (fig. 2). Belonging to a widely
distributed group, covering most of the prairie and Great
Plains region of the United States and southern Canada,
they are fortunately never so numerous as some of the
other species of ground squirrel. They inhabit both the
prairie and brushy areas, but usually are not found in
heavy timber or on low, wet ground. Open grassy ridges
and dry prairies are their favorite habitat, and here
their numerous burrows and striped coats afford the best
of protection.
General habits.--They
are true ground squirrels, spending all but their working
hours below the surface in their well-made dens and burrows.9
They are strictly diurnal and are partial to warm weather.
Early on bright summer mornings they may be seen running
over the prairie in search of food or mates or in playful
exercise, but in cold or chilly weather they keep mainly
within their burrows, where a supply of food is generally
stored. In the tall grass, weeds, or brushy patches they
keep out of sight for the most [p.53]
part and would rarely be noticed but for their call notes,
long bubbling trills, given as signals of alarm or to
convey other information among themselves.
Breeding habits.--Breeding
activities begin soon after the adults emerge from hibernation
in March or early in April, but the actual dates of birth
of young are not easily obtained. Females collected in
May usually contain embryos showing various degrees of
development, but the young do not appear above ground
until June or July. They are then nearly half grown and
able to run about and take care of themselves under the
watchful care of their mothers. When first born the young
are very small, naked, and helpless. Doctor Hoy (Kennicott,
1857, pp. 76-77), who observed them in confinement, says
that they have no hair on the body before they are 20
days old, and that the eyes do not open till the thirtieth
day. The number of young in a litter varies widely, but
seems to be usually from 7 to 10. A female taken by Sheldon
at Fairmount, on May 9, contained 11 embryos, and there
are other records of still larger numbers up to 13 (Lee)
and 14 (Seton). The full number of mammae in adult females
is 12. Apparently but one litter of young is raised in
a season, and even for that the time is short for them
to mature and lay up sufficient fat and food to carry
them through the six months of hibernation.
Food habits.--Although
a great part of their food consists of seeds, grain, and
nuts, they are omnivorous in habits and take besides berries
and some green vegetation, numerous insects, and the flesh
of mice, birds, or any small animals which they can capture
or find dead. Acorns and hazelnuts are eagerly gathered
and stored for winter food, but over most of their range
only the smaller seeds and nutlets are obtained, unless
grainfields are within reach. Seeds and grain are stored
for future use, but much soft food that will [p.54]
not keep is eaten as it is taken. The examination of the
contents of large numbers of stomachs shows a considerable
portion of grasshoppers, crickets, caterpillars, beetles,
ants, cocoons, insect eggs and even traces of flesh, hair
or small mammals, and feathers of birds; also green foliage,
the white pulp of bulbs and tubers and the fruit of solanum,
cactus and strawberries. The contents of the ground squirrel's
capacious cheek pouches give a good index to the selection
of seeds and grains. The pouches are often distended with
wheat, oats, barley, rye, or any of the cultivated grains
that are obtainable, but also are found to contain acorns,
hazelnuts, seed of sunflower, cactus, bindweed, goosefoot,
puccoon, wild peas and beans, and a great variety of grass
seeds.
During late summer and
fall, all work industriously, laying up their winter stores,
quickly filling their cheek pouches and running to the
burrows to empty them into the storage cavities near the
winter nests. The seeds of native plants are gathered
over a considerable area. Sometimes a quart or more is
found in a storage chamber, and at the edge of a field
where an abundance of grain can be rapidly gathered the
winter's stores assume much larger proportions.
Economic status.--In
spring the planted seed is dug up and eaten or stored
from the time it is sown until long after it has sprouted.
Then the green stalks are eaten during the early summer,
and as soon as the grain is headed out great numbers of
the heads are cut off for kernels, from the very beginning
of their formation. Thus, before harvest time the edges
of the grainfields have become ragged and thin for a considerable
distance into the field. Although depredations of these
ground squirrels do not compare with those of the more
abundant Flickertails, their wide distribution over North
Dakota and many other States renders them one of the most
serious of rodent pests.
But for their natural enemies,
which are legion, it would be impossible to raise crops
within their territory. They are constantly preyed upon
by many species of hawks, and some owls, and by foxes,
weasels, skunks, and badgers, so that in spite of their
rapid increase their numbers are usually kept somewhat
within bounds. However, it is necessary over much of their
range to supplement the work of their natural enemies
by the systematic use of poison.
| FIG. 2.--Distribution of the thirteen-lined
ground squirrel (1), and its pale western form (2),
in North Dakota |
Citellus tridecemlineatus pallidus
(Allen)
Pale Striped Ground Squirrel; Pale Thirteen-lined Ground
Squirrel
Miniwakao of the Cheyennes
[Spermophilus tridecemlineatus]
var. pallidus Allen, Monogr. North Amer. Rodentia,
p. 873, 1877.
Type locality.--Plains
of Yellowstone River, Mont.
General characters.--A
pale western form of the thirteen-lined ground squirrel,
slightly smaller, and with paler tones of buff and lighter
brown stripes. Average specimens from the type region
measure in total length, approximately 255 millimeters;
tail, 82; hind foot, 84.
Distribution and habitat.--The
striped ground squirrels become gradually paler across
the middle part of the State, but not until the semiarid
Badlands country is reached west of the Missouri [55p.]
do the pale forms become clearly recognizable. In the
part of the State west and south of the Missouri, they
are the only ground squirrels, and here with the prairie
dogs they occupy the short-grass plains country in considerable
numbers. While sometimes seen in the open, where there
is not sufficient grass to conceal them, they are more
often found in the better cover of grass and weeds and
low bushes. In this region they were originally one of
the interesting and harmless forms of native life, but
since grain farms have spread over it they have become
one of the serious problems with which the farmer has
to contend.
General habits.--In
habits these squirrels do not differ from their darker
relatives to the eastward, except as a change of environment
gives them other kinds of food and local conditions which
they seem always ready to meet. In many places some protection
is sought for their burrows, such as grassy spots or weedy
ground. Sometimes a piece of paper or cloth is drawn over
the entrance to the burrow, apparently for concealment
or protection.
At Parkin, on June 28,
1916, a burrow was found where fresh earth had been lately
thrown out and the entrance was securely packed with sand
from the inside. As the entrance to this burrow was opened
a half-grown young of the species poked its head out of
another entrance near by. In the tunnel, about 8 inches
below the surface of the ground, was found a large, soft
nest in a roomy chamber, with two doors opening out on
opposite sides. The nest was made of dry grass, bark fibers,
and bits of paper from the railroad track. It was soft
and well matted together like a bird's nest, but not covered
over. The young had escaped in the branching burrows.
Evidently this was their home nest, from which they had
not yet begun to make excursions to the world above. The
closing of their doors from within was evidently in this
case to protect the young from outside enemies.
Economic status.--In
many places it has been found necessary to poison these
squirrels for the protection of grainfields and garden
crops; the methods given for the Richardson ground squirrel,
or flickertail, will be found to apply equally well to
this species.
Citellus franklinii (Sabine)
Gray Ground Squirrel; Franklin Ground Squirrel
Arctomys franklinii Sabine,
Trans. Linn. Soc. London, vol. 13, p. 587, 1822.
Type locality.--Carlton
House, Saskatchewan, Canada.
General characters.--Largest
of the ground squirrels of this region; sometimes mistaken
for the gray tree squirrel, which it approaches in size
and slightly resembles, but from which it differs in slender
form, very short ears, and much smaller and less bushy
tail. Color, dark gray with a brownish wash and a mottled
effect in fine, wavy cross lines or scallops over the
back. Adults measure in total length 388 millimeters;
tail, 136; hind foot, 55.
Distribution and habitat.--Extending
over a wide range in the central United States and Canada,
from Oklahoma and Illinois to the Athabaska River, the
large gray ground squirrels cover approximately the eastern
half of North Dakota (fig. 3). Their greatest abundance
within the State lies within the Red River Valley and
westward to the Dakota River Valley, Devils Lake, and
the Mouse River. There is an indefinite record for Burleigh
County near Bismarck, [p.56] and another
for Turtle Lake in McLean County, but the most westward
authentic record is from Kenmare, in the valley of the
Riviere des Lacs, where W. B. Bell collected a specimen
in 1913. They are particularly animals of open timber
and brush land and do not occupy wide stretches of prairie
unless there is ample cover for concealment.
| FIG. 3.--Records of the Franklin
ground squirrel in North Dakota |
General
habits.--Although occasionally seen up among the branches
of low trees, the Franklin squirrels are strictly ground
squirrels, living in burrows generally concealed in brush
or weed patches, from which well-worn trails or runways
radiate to other burrows or feeding grounds. They are
shy and secretive, keeping much under cover of protecting
vegetation, as they are too large and dark colored to
be inconspicuous the open. When frightened they rush for
their burrows, usually uttering a trill of alarm and warning
to other members of the family. Their voice is much like
that of the thirteen-lined ground squirrel but is as much
heavier as they are larger. It is often heard in a long
bubbling trill from a weed patch and is almost birdlike
in musical quality.
In the timber and brush
patches along the Red River Valley, about Stump Lake,
Devils Lake, the Sweetwater Lakes, and in the Turtle Mountains,
the squirrels are especially numerous and in such situations
they are generally the most abundant of the three species
of ground squirrel occupying the general region. Throughout
the Turtle Mountains they were found along the edges of
meadows, fields, and clearings along roadsides, and in
all the open places where woods and small brush served
for cover. They gathered around camps or dwellings where
there were no dogs or guns and even came into the writer's
cabin and helped themselves from the grub box. They persisted
in getting into traps set for others long after enough
of them had been secured for specimens and most of the
trails and runways attributed to other animals proved
to belong to them.
[p.57] Their burrows were generally in
groups of three or four, or more, not far apart and evidently
connected below ground. They were in all sorts of situations,
but a sloping bank, brush heap, old log, or stone pile
usually provided the protection sought for their dens.
A considerable quantity of earth is usually thrown out
in front of one of the burrows but others open out with
less conspicuous markings. Many old dens and burrows are
located through the brush and woods and one seems always
to be convenient when danger approaches. Often the animals
will stop at the entrances of their burrows and straighten
up in the picket-pin attitude, to make sure whether an
enemy is pursuing. If approached too closely, they quickly
dive into their burrows with a flirt of the tail and a
parting chatter, but if all is quiet they soon reappear
cautiously to reconnoiter.
Franklin squirrels are
easily tamed and make interesting, though rather mischievous,
pets. H. V. Williams, at Grafton, had a tame one for which
he made a den by burying a box underground. The squirrel
carried about a half bushel of grain into this box, and
in fall hibernated as usual. When examined in January
it was unconscious, but before its awakening time in spring
water ran into the box and it was drowned. While collecting
specimens at Fish Lake in the Turtle Mountains, Williams
fed one around his tent until it became so tame as to
take food from his hand and come to the tent regularly
at meal times. It finally became so bold that it would
enter the tent and search through the baggage for food.
After breaking and carrying off a lot of birds' eggs that
had been collected for specimens it had to be killed to
prevent further trouble.
Hibernation.--With
the first freezing weather in fall, usually in September,
Franklin squirrels go to their nests deep underground
and usually do not reappear until the following April.
Before entering upon their hibernation they become very
fat and depend upon this concentrated form of nutriment
to carry them through the winter rather than upon the
ample stores of food laid up in convenient chambers near
their nests. Just when these stores are eaten is not well
known, but probably before the squirrels have become entirely
inactive in fall and again before the outside food supply
is available in spring.
Breeding habits.--Their
half dozen young are usually born in May or June and by
the last of July are half-grown squirrels, out of the
burrows, and hunting for their food.
Food habits.--Living
largely upon nuts, seeds, and grain, these squirrels show
an appetite for a wide range of food. The examination
of a large number of stomachs and cheek pouches shows
their food to consist not only of a great variety of grains
and seeds, but also of berries, green vegetation, roots
and bulbs, beetles, caterpillars, grasshoppers, crickets,
ants, and eggs and pupae of insects. They also eat young
birds, birds' eggs, and young mice, and are said to kill
young chickens. When caught in traps or found dead they
are even eaten by their own kind. They feed upon grain
from the time the seed is planted until the last bundle
is removed from the fields. Unlike the smaller ground
squirrels, they do not cut the standing grain, but pull
down the heads and in this way destroy the grain even
more rapidly. In their capacious cheek pouches seeds of
[p.58] grain are rapidly carried to their
winter storehouses. Where a large number of the squirrels
gather along the edge of a field they will often harvest
considerable of the grain after having fed upon it during
every stage of its growth through the summer.
Economic status.--To
a great extent the Franklin squirrels occupy the limited
areas where the other two ground squirrels of the State,
the thirteen-lined and the Richardson, are absent or less
numerous. In extensive areas, therefore, they are the
dominant species and levy their toll of destruction on
the grainfields and gardens that otherwise would be comparatively
safe. In some places, however, the three species occupy
the same ground and in combined numbers cause enormous
losses of crops. Although larger and according to their
numbers possibly more destructive to grain than the Richardson
squirrels, the Franklin ground squirrels are apparently
less numerous in most of their habitat. They are easily
poisoned and their abundance may be controlled at comparatively
little expense, using the same methods as recommended
for the Richardson, or flickertail.
Citellus richardsonii (Sabine)
Richardson Ground Squirrel; Flickertail
| Honkóta of the Arikaras;
Pinsa of the Dakotas; Shopka-sop of
the Mandans; Tsipá sopa of the Hidatsas
(all, Gilmore). |
Arctomys richardsonii Sabine,
Trans. Linn. Soc. London, vol. 13, p. 589, 1882.
Type locality.--Carlton
House, Saskatchewan, Canada.
General characters.--A
plump little ground squirrel much resembling the prairie
dog, but about half the size. Color, rich buffy yellow,
darkened over the back with obscure mottling and wavy
scallops. Ears, minute; tail, short. Measurements of average
adult: Total length, 237 millimeters; tail, 73; hind foot,
45. Ebner gives the usual weight In fall as 16 to 17½
ounces and in spring as 11 to 13 ounces.
Distribution and habitat.--From
a wide range over southern Saskatchewan, Alberta, and
Montana, Richardson ground squirrels, or flickertails,
cover practically all of North Dakota east and north of
the Missouri River (fig. 4). They are absent from most
of the immediate valley of the Red River and the wooded
bottoms and timbered areas generally being most abundant
over the high open prairie of the central part of the
State. For some unknown reason they seem to stop at the
Missouri River where the prairie dogs begin, although
the ranges of the two species overlap slightly in Montana,
where no enmity between them is noticeable. The more humid
and fertile part of the country was occupied by them long
before the great wheatfields spread over their range to
supply a new and choice food. Of the three species of
ground squirrel in the State, these are by far the most
numerous and most destructive.
| FIG. 4.--Records of the Richardson
ground squirrel in North Dakota |
General
habits.--Originally the flickertails had a continuous
distribution over the prairie in great numbers. On some
favorite slopes they were so numerous as to suggest a
colonial tendency, but apparently this only showed a preference
for certain kinds of ground yielding an abundant food
supply.
In 1887, when much of the
prairie was still unbroken, they were living in their
primitive manner on such food as the prairie afforded
and doing practically no harm except as grainfields and
crops encroached [p.59] upon their original
range. Their greatest numbers often appeared to be in
the areas of the shortest grass and lowest vegetation,
possibly because the grasshoppers and other insect life
on which they fed to some extent were most easily obtained
there. In places the prairie seemed alive with them and
they could be seen scampering about together or standing
up like picket-pins, while their shrill whistle was heard
on all sides. With each call-note their short little tails
are flipped up and down, a farewell twinkle being given
as they disappear down the burrow, hence the popular name
of "flickertail." In 1887 they were often seen also in
the main streets of Devils Lake and Bottineau, which were
then in their early stages of construction, and in 1916,
it was most surprising to find them still occupying vacant
lots on the edge of the city of Devils Lake. It was a
striking illustration of their tenacity in holding to
their original habitat through years of vigorous but sporadic
efforts to destroy them.
As soon as the grainfields
spread over their range they quickly gathered along the
edges to feast on this wonderful new and abundant food.
They did not long confine themselves to the edges of the
field, however, but went into the middle of large cultivated
areas and made their burrows in the plowed ground or in
the growing grain.
No reliable estimate of
their numbers can be obtained, but a general idea of their
abundance may be gained from the statements of Elmer T.
Judd, of Cando, in a letter of August 1, 18,90, in which
he, says:
An old gentleman here killed 1,500 'gophers' by actual
count, before the first of June. From the first of June
to the middle of July, he and a cotton broker from St.
Louis, who spends the summer here on his farm, calculated
that they killed over 2,500 more. One forenoon they killed
135, as shown by the tails they had captured.
[p.60]
These 4,000 animals were killed on and around the outer
edges of one section of land.
Breeding habits.--The
number of young to a litter is given by Ebner as 6 to 11,
with an average of 7 or 8, born in the underground nests
mainly in May. By the first of June the young are out of
the burrows and find part of their own food while still
under the anxious care of their mothers. Small young are
occasionally seen much later than the first of June, and
apparently the breeding season extends over a considerable
period. It has been supposed that flickertails raise two
or more litters in a season, but this seems improbable on
account of the brief period between their emerging from
hibernation in the latter part of March or early April,
and entering hibernation in the latter part of August or
early in September. This is scant time for even the earliest
young to get anywhere near their full growth and lay in
sufficient fat to carry them through the winter. By the
first of September there are always many individuals that
are still small and these are the last to hibernate, presumably
because they have not laid up sufficient fat. Even in spring
many of those that are seen before the young are born are
not nearly full grown and apparently these late young of
the previous year are late in breeding. The principal mating
season is early in the spring soon after hibernation but
sometimes it is as late as the latter part of June. On September
1, 1914, at Bismarck, a few were seen but these were the
young of the year, the adults having already gone into their
winter dens. At the same time, Silver, who had been studying
them at Garrison, for the previous week reported only young
of the year caught. At Van Hook on October 16, 1919, the
writer saw one out on a warm, sunshiny day after a cold
wave, but none had been seen before for some time.
Food habits.--During
the summer much green vegetation is eaten by the flickertails--largely
the leaves and stems of grain, grass, and a great variety
of succulent plants--and apparently it would be possible
for these rodents, like the prairie dogs, to subsist entirely
upon such vegetation were no grain and seeds available.
Late in summer and in fall, when the seeds of the prairie
plants and grasses begin to ripen, they constitute the principal
food of the squirrels. An important part of the summer food
consists also of such insects as grasshoppers, crickets,
and caterpillars, though these vary greatly with season
and locality. At Crosby, in July, 1913, they were found
feeding extensively on the little juicy striped-backed armyworm
caterpillars, which swarmed over the roads and fields. Some
of the squirrels examined had their stomachs half full and
others entirely filled with the caterpillars. Where grasshoppers
are abundant they are often fed upon extensively, but wherever
grain can be obtained it seems to be the favorite food.
One flickertail, shot as it ran out from under a shock of
grain, had 269 kernels of oats in its cheek pouches. One
recorded by Seton had 162 grains of oats in its pouches
and another 240 grains of wheat and nearly a thousand grains
of wild buckwheat. Their cheek pouches are so capacious
that when well filled they often make the head appear more
than double its natural size. The stores gathered are rapidly
carried home to be deposited in the burrows and large quantities
of food are thus provided for future use. No [p.61]
stores of grain have been found in the hibernating dens,
however, and more study is needed to show when it is used.
Destruction of crops.--The
annual loss in grain crops in North Dakota occasioned by
these ground squirrels has been estimated at $6,000,000
to $9,000,000 in addition to the annual expenditure of at
least $100,000 of public and private funds to combat their
depredations. Their tendency is to multiply rapidly in a
well-settled and cultivated part of the country because
many of their natural enemies are destroyed or kept at a
distance, and the food supply is most abundant. As soon
as they emerge from hibernation early in spring they begin
digging up the seed and eating the young grain that has
been sown in the fall and as soon as the spring sowing starts
they dig up the new seed and eat or carry it away. When
the grain sprouts they dig both sprout and kernel, and after
the kernels are entirely exhausted they feast on the young
growing grain until it is headed out, when they begin on
the young heads, cutting down the stalks and eating the
young seed through all its growing stages. As soon as the
grain is ripe they carry it away as rapidly as possible
to their storehouses, and this is continued until the last
bundle is removed from the fields. Four thousand of these
squirrels on or around the edges of a section of land would
remove a considerable portion of the crop, and it is not
surprising that they are considered the greatest pest of
the region. They seem to have no preference between wheat,
rye, barley, oats, or flax, but take whatever is nearest
their dens.
Natural enemies.--The
natural enemies of these ground squirrels are numerous,
and but for them the abundance of the animals would be many
times greater. Badgers are constantly digging them out and
feasting upon them, from early spring until long after they
have hibernated or until the ground becomes well frozen
and the badgers themselves go into winter quarters. The
long-tailed weasels enter their burrows and kill and feed
upon them without the least trouble or hindrance and apparently
destroy great numbers besides those merely killed for food.
At the first appearance of one of these weasels, the squirrels
give frantic alarm calls that set the whole prairie community
in a panic. They rush to their burrows, but the weasel follows
and helps itself to as many as it cares to kill for food
or pleasure. This goes on as long as the burrows are open
and probably even during the winter, when the weasels can
gain access to the dens through the snow, as they are active
all winter and sleeping squirrels fill their needs as well
as any others. Skunks probably dig out a few, and foxes,
coyotes, and bobcats help also to reduce their numbers.
Hawks and some owls prey
upon them to a greater or less extent. The ferruginous rough-legged
hawk apparently feeds upon them almost exclusively where
they occur in its neighborhood and brings them in to feed
its hungry broods. The Swainson, marsh, red-tailed and red-shouldered
hawks feed on them extensively, and even the bird-catching
sharp-shinned and Cooper hawks may occasionally take one.
The little sparrow hawks, which feed mainly upon grass hoppers,
probably destroy some of the young ground squirrels, and
it is likely that both the short-eared and long-eared owls
capture many of them during early evenings or on cloudy
days. Gopher [p.62] snakes feed upon them
to considerable extent, but few data are available in regard
to some of the most important species of snakes. The protection
of such of their natural enemies as are not otherwise harmful
in habits is one of the most important measures for the
control of these ground squirrels.
Methods of destruction.--Most
efficient methods of controlling these ground squirrels
have been carefully worked out by members of the Biological
Survey and the North Dakota Agricultural College and Experiment
Station. In campaigns against these squirrels, the most
economical preparation of poison that has been found to
be effective is grain lightly coated with strychnine and
starch in the proportions of 1 ounce of strychnine alkaloid
to 1 tablespoonful of gloss starch made into a paste with
1 pint of boiling water and stirred into 20 quarts of oats.
A teaspoonful of this coated grain placed near each occupied
burrow disposes of a large percentage of the squirrels at
the first application and the few that remain can be practically
cleaned up at the second application. Well-organized and
coordinated work over a large area is necessary for satisfactory
results, as no matter how thoroughly the squirrels are cleaned
out from one or a half dozen farms they will quickly reinfest
the whole area from those remaining. This preparation of
poisoned grain is equally successful with the other species
of ground squirrels and chipmunks where it is necessary
to reduce their numbers or clean them out of a section of
country.
Ground squirrels as pets.--On
a street car from Devils Lake to the Chautauqua Grounds
one day the writer saw a boy who had one of these squirrels,
which he had caught with a snare earlier in the day. It
was about half grown and had become so gentle that he was
playing with it and handling it freely, letting it climb
his coat sleeve and carrying it in his pocket or in his
cap on his head. It made no attempt either to escape or
to bite, but snuggled up to him in a way that suggested
the possibility of using these squirrels as pets for children,
a vital need that is not well met by any of our domestic
animals. Cleaner, neater little pets could not be found.
Although quiet in disposition, they have sufficient vivacity
to be very attractive. If taken young and well tamed these
native squirrels would certainly be far more attractive,
interesting, and intelligent than white mice, rats, or guinea
pigs, which seem to be the only small mammals available
for this important phase of child development. The supply
would be endless and easily obtained, and by using only
one sex in one part of the country any danger from recolonization
would be avoided.
Cynomys ludovicianus ludovicianus
(Ord)
Black-tailed Prairie Dog
| Pinspinsa
of the Dakotas; Achks of the Arikaras; Shopka
of the Mandans; Sinhpa
or Tsipá of the Hidatsas (all, Gilmore). |
Arctomys ludoviciana Ord, Guthrie's
Geogr., 2d Amer. ed., vol. 2, pp. 292, 302, 1815. (Reprint
by S. N. Rhoads, 1894.)
Type locality.--Upper
Missouri River, where discovered by Lewis and Clark.
General characters.--Prairie
dogs might be described as big, husky ground squirrels
or little, plump woodchucks, to both of which they are
related and [p.63] between which they
range in size. Although belonging to the squirrel family,
they are compactly built for digging and for life on and
under the surface of the ground. The ears are minute,
the tail short, and the legs short and muscular. The color
generally matches well the fresh yellow earth of their
burrows, being a yellowish or pinkish cinnamon above and
buffy below; the tip of the tail is blackish, and coarse
black hairs are scattered over the upper parts; the fur
is soft and silky in winter, coarse and harsh in summer.
Average measurements: Total length, 388 millimeters; tail,
86; hind foot, 62.10
Weight, 2 to 3 pounds.
Distribution and habitat.--From
a wide range over the Great Plains from western Texas
to northern Montana, these prairie dogs extend over that
part of North Dakota west of the Missouri River (fig.
5). In this latitude they are all west of the Missouri
River, but farther south they occur on both sides. Fortunately
they are colonial in habits and have a scattered distribution,
so that the country is not fully occupied by them, but
the colonies, or "dog towns," have been numerous over
the part of the State which they occupy. In 1910, Anthony
reported a few prairie dogs on the south side of the river
not far from Buford, and many 20 miles south of there.
In 1909, prairie-dog towns were reliably reported near
Mannhaven, just west of the Missouri River, and on the
Little Missouri near Marmarth in the southwest corner
of the State. In 1913 there was a considerable dog town
east of Sentinel Butte. In 1913, Jewett reported a large
colony on the flats about a mile west of Fort Clark, where
the prairie dogs were doing considerable damage to crops,
another colony on a piece of level prairie about 3 miles
east of Oakdale, and many others along the Little Missouri
River from Quinion to Medora, with exceptionally large
colonies at the mouth of Ash Creek and near the head of
Magpie Creek. Most of the dog towns he found around Sentinel
Butte had been destroyed, but a small colony still existed
about 10 [p.64] miles east of there.
A considerable dog town was located a couple of miles
east of Medora and another along the Northern Pacific
Railroad between Hebron and Glen Ullin. Kellogg, in 1915,
found near Goodall an uninhabited dog town that had covered
about 400 acres. A small colony on the west side of the
river opposite Elbowoods was said to be decreasing in
population. About a mile north of Mannhaven a colony was
found covering about 100 acres. At Stanton there had formerly
been a large colony but it had been destroyed by poison.
In 1915, Sheldon reported a small prairie-dog town on
Deep Creek near the former Dakota National Forest, and
other colonies scattered over that general region. At
a point about 4 miles northwest of Cannon Ball he located
a town containing about 2,000 prairie dogs and covering
an area of approximately 160 acres. Another colony was
located near old Fort Rice, covering about 40 acres and
containing about 500 animals; still another about 9 miles
south of Cannon Ball of approximately 90 acres and about
500 animals. He was told that the Indians had kept them
down by shooting them for food. Near Wade, in 1913, Doctor
Bell reported them as occurring in scattered colonies.
| FIG. 5.--Distribution of prairie-dog
towns in North Dakota |
In
1915, U. S. Ebner, in charge of field operations in the
rodent control work of the Biological Survey in cooperation
with the North Dakota Agricultural College and Experiment
Station, investigated the prairie-dog situation over a
part of the range west of the Missouri River. He reported
small prairie-dog towns covering 25 to 250 acres scattered
along the Little Missouri River in Billings County, larger
colonies of 60 to 640 acres in the northern part of Dunn
County, a number of towns of 20 to 160 acres along Big
Beaver Creek in the northern part of Golden Valley County,
other towns of 25 to 500 acres in the eastern part of
McKenzie County, and some large towns running as high
as 600 acres on the Berthold Indian Reservation. In most
of these prairie-dog towns he estimated 20 to 40 burrows
to the acre.
Although these records
show only the colonies that have been located, they indicate
a very general distribution of prairie dogs over this
part of the State, and a careful survey would doubtless
show a surprising number of inhabited prairie-dog towns
in a region that is rapidly filling up with grainfields.
As a general thing the
colonies are located on the open level prairie and often
on the best of the grain land. In the Badlands they are
usually on the flat and level spaces where the best grass
grows, always away from the brushy and barren areas.
General habits.--Prairie
dogs are highly social in disposition, almost invariably
living in colonies. On rare occasions a new location is
chosen where family or a few prairie dogs have started
a colony, but generally there is evidence of their long
residence. The old burrows and mounds remain for many
years and the sites of ancient prairie-dog towns are marked
by little swells of grassy turf scattered over the prairie.
A well-populated prairie-dog
town on a bright summer morning is as animated as any
busy village could well be. At the first appearance of
the sun the animals come out of their burrows and begin
their breakfasts of grass and roots, most of them busily
digging up grass and little plants for food, nibbling
off the grass blades and [p.65] plant
leaves like rabbits, or sitting up holding them in their
hands like squirrels. There are always, however, a few
on sentinel duty, usually sitting straight up on the highest
mounds, or stretching up occasionally to full height from
the grass where they are feeding. Some are always scampering
from one point to another, and when the young are out
there is much playing and scuffling among them.
A populous town of prairie dogs, all busy and many of
them calling back and forth, with a few on sentinel duty,
barking in steady little yap-yap-yap-yaps at some
real or imaginary enemy, makes an interesting picture.
If an enemy really approaches, the barking becomes frantic
and is taken up by other members along the line, and there
is a general scamper for the nearest burrows. If one walks
toward them to within rifle range the panic increases
and the nearest animals rapidly disappear down the burrows
with a farewell twinkle of their tails. The barking passes
along farther and farther through the town, usually beyond
where the enemy can be seen, every prairie dog taking
notice and most of the them joining in the alarm. Occasionally
one of the guards will stretch up to its utmost height
and throwing its head back utter a long Chu-r-r-r-r-r-r-r-r-r-r,
as if a dozen barks were crowded into one. This seems
to be their only note besides the regular yap-yap,
and a chuckling, scolding Chu-r-r-r-r-r, after
entering their burrows, as if they were grumbling at having
been disturbed.
The burrows are deep and
go down at steep angles, sometimes almost straight down,
for 2 or 3 feet and then slope off gradually. A pebble
dropped into one can be heard rolling and bounding down,
often for 5 or 6 feet, and a prairie dog with a string
tied to its hind foot will sometimes take down 12 or 15
feet of string before reaching the end of the tunnel.
The burrows are simple and almost never lead out to a
second opening.
The nest, instead of being
at the lowest point, is usually in a chamber well protected
from any rain water that may run down the burrow. As a
further protection the earth thrown out is carefully placed
around the entrance to form a craterlike rim that serves
the double purpose of a watch tower and a dike to prevent
the entrance of water from heavy rains.
Originally the mound is
built of the earth brought out of the burrow, but later
fresh earth is scraped up from outside and brought back
and added to the sides, and when the ground is moist after
a rain the mound is carefully formed and patted and pushed
with the end of the nose until externally it has the most
approved slopes and internally the correct funnel form.
A well-kept mound shows numerous dents and dimples where
pushed and poked with the pudgy noses of the prairie dogs.
Many old burrows with neglected and broken mounds are
used, but the main nest burrows are always kept in good
condition. Nest material of dried grass and soft plant
fibers is carried into the burrows and the old material
is occasionally brought out and scattered about the entrance.
The cheek pouches of the prairie dogs are small and little
used, and apparently no food is stored.
Breeding.--The 4
to 6 or 8 young are born early in May, but usually do
not appear out of the burrows until the first or middle
of June. They are then seen in family groups around the
entrance to [p.66] their homes and always
under their mother's watchful eye. At a signal from her
they quickly rush to the burrow and disappear. As their
experience increases they are left more to their own discretion,
but even when half grown if danger appears the mother
insists on their all getting down the burrow before she
will enter. Small young are often seen later in the year,
but in the northern part of their range it is doubtful
if more than one litter is raised in a season, the late
young probably being the first litter of females of last
year's brood.
Hibernation.--In
fall the adults become very fat and the young moderately
so. They are always ready to hibernate in case of very
cold or stormy weather or deep snow, but do not enter
their dens to remain unless cold weather comes. In mild
seasons they are sometimes active until midwinter and
may be seen foraging on warm days when there is no snow.
In severe winters, however, they disappear for a long
period and evidently pass completely into the state of
hibernation. They are out with the first warm days of
spring and in March, when a few sagebrush tops were the
only visible vegetation, the writer has seen them sitting
on top of 2 feet of snow through which they had burrowed
to the surface. As soon as the snow is off in spring they
find plenty of food in the dry grasses and roots, and
their store of fat helps to carry them through the mating
season.
Food habits.--The
food of the prairie dogs consists principally of grass,
including seeds, leaves, stems, and roots, but it includes
also everything that grows over the surface of the ground
to a considerable distance around their burrows. The short
blades of grasses are not only eaten off to the ground,
but the roots also are dug up and the tender bottoms of
many species are eagerly eaten. Other little plants are
eaten to the ground and those with edible roots or bulbs
are dug up and exterminated. Often tall plants, grasses,
and weeds that have sprung up in the prairie-dog town
are cut down, if not for food, to keep the ground clear
and the view unobstructed. An old and well-populated prairie-dog
town is often so completely cleared of vegetation that
parts of it have to be abandoned, the animals moving on
toward the best grass on the margins. In this way parts
of the prairie are progressively denuded of vegetation.
The stomachs of prairie
dogs are relatively large, as in all grazing animals,
and at any time of the day except early morning they are
found well filled with finely masticated vegetation, usually
showing a good combination of green and white pulp from
the foliage, stems, and roots of plants, often with streaks
of color from various kinds of flowers and seeds. Many
ripening seeds are included in their food, and fields
of grain tempt them to extend their colonies into this
unusual food supply. When the dog towns are plowed up
and seeded to grain the occupants cling to the old burrows
with great tenacity, opening them up and if left undisturbed
living in the midst of wide grainfields.
Depredations.--An
area occupied by a colony of prairie dogs may usually
be considered stocked to its carrying capacity and of
little or no value for grazing or agricultural purposes.
It may also be considered that the area thus occupied
is just so much withheld from [p.67]
other use, and it is only a matter of determining the
area of land given over to these animals to know the extent
of the loss in grazing. If a well-populated prairie-dog
town is plowed and seeded, prairie dogs will be the ones
to harvest the grain unless they are first destroyed.
Destruction of prairie
dogs.--Fortunately prairie dogs are easily poisoned
by the use of oats or other grains coated with strychnine,
as described for the Richardson ground squirrel, and a
farm suffering severe losses may be reclaimed at comparatively
small expense. Full directions for preparing and using
the poisons will be furnished by the Biological Survey
on request.
Marmota monax rufescens Howell
Rufescent Woodchuck; Groundhog
Marmota monax rufescens Howell,
Proc. Biol. Soc. Washington, vol. 27, p. 13, 1914.
Type locality.--Elk
River, Minn.
General characters.-Heavy-bodied
animals, with short ears, short legs, and short, bushy
tails. Similar in general appearance to the southern and
eastern woodchucks, but more reddish brown above and below.
Upper parts dark brownish gray, sides and underparts strongly
washed with reddish or rusty brown; feet blackish; tail
black or dark brown, longhaired and bushy. Average measurements:
Total length, 548 millimeters; tail, 143; hind foot, 83.11
Weight, about 8 to 12 pounds, but individuals have been
recorded as heavy as 13½ and 18 pounds. (Anon.,
1900; Fellows, 1881.)
Distribution and habitat.--From
the Transition Zone of the eastern United States woodchucks
extend across Minnesota and into southeastern North Dakota
as far as Devils Lake (fig. 6). In revising the group
Howell examined specimens from Fargo, Grafton, and Leonard,
in North Dakota; and at the biological laboratory in 1913
there were skins collected near Stump Lake and Devils
[p.68] Lake. At Wahpeton woodchucks are
reported common along the banks of the timbered river
bottoms. At Fargo and Grafton they are occasionally found.
In 1915, Kellogg collected a half-grown young near Larimore
and obtained a specimen at Grafton. While at Manvel, Grand
Forks County, he saw their burrows and one young that
had been captured. In 1919, Williams reported then becoming
more numerous each year at Grafton. Eastgate says they
are occasionally found in the forest near the biological
laboratory at Devils Lake, but that they are by no means
common. Apparently they fill the forested belts along
the rivers, extending west from the Red River Valley and
thus reaching the Devils Lake and Stump Lake forested
tracts. Although mainly restricted to forested and brushy
locations, where no timber is available they will live
in the open. Steep banks and sidehills are favorite situations,
but in many cases the burrows are found on level ground
or under stumps, trees, or stones. Woodchucks are not
fastidious as to habitat, the one requisite for their
existence seeming to be an ample supply of green food
during the summer season.
| FIG. 6.--Localities where woodchucks
are known in North Dakota |
|
