_Perognathus hispidus_]
[Illustration: POCKET GOPHER
_Geomys bursarius_]
Muskrats are usually harmless animals and their presence in marshes
and along watercourses lends a pleasant touch of primitive wildness to
the most commonplace situations. They appear to have so adapted their
habits to the presence of men that they go on with their affairs with
curious indifference to their human neighbors. In irrigated country
or elsewhere where banked ditches are built their habits render them
serious pests, as their burrows and tunnels drain ponds or cause
destructive washouts.
An interesting chapter in the history of these animals began in 1905,
when four Canadian muskrats were introduced on a nobleman’s estate
in Bohemia. Since then they have increased rapidly and spread over a
large area in Bohemia and beyond its borders. The streams in the region
they occupy are controlled by grassy banks, and dams are built to form
ponds for fish culture, which is a large industry there. The muskrats
persistently tunnel into the banks and dams, causing them to give way,
thus causing heavy losses to the owners.
They also work havoc among river crabs and mussels, which have great
economic value, and interfere with the fish and their spawning beds.
To cap the climax of their misdeeds, they are reported to feed on
grain and vegetables and to destroy the eggs of domestic poultry and
of wild-fowl. It is reported also that these expatriates in their
foreign environment have become larger animals than their ancestors,
and that their fur has greatly deteriorated in quality. The measures
prescribed by the Agricultural Council of the Kingdom of Bohemia for
their control are apparently without much success. This instance is a
good illustration of the danger attending the introduction of an animal
from its native habitat into a new region.
=THE WOODRAT= (=Neotoma albigula= and its relatives)
(_For illustration, see page 526_)
In the East known as woodrats, in the West, where much more numerous
and better known, these animals are called “mountain rats” or
“trade rats.” Despite a certain superficial resemblance in size and
appearance, woodrats are not related to those exotic parasites,
the house rats, with coarse hair and bare tails, but are far more
attractive and handsome animals, clothed in fine soft fur, delicately
colored above in soft shades of gray, buffy, or ferruginous, while
below they are usually snowy white or buffy. The tail is fully haired
and in some species almost as broad and bushy as that of a squirrel.
Their prominent black eyes and large ears give them an air of vivacious
intelligence which their habits appear to confirm.
Woodrats are peculiar to North America, where they occur from
Pennsylvania and Illinois to the Gulf coast, spreading thence to the
Pacific and as far north as the headwaters of the Yukon, and south
through Mexico and Central America to Nicaragua. They are not plentiful
in the southern Mississippi Valley and eastward, where they live among
cliffs and broken ledges of rock in the deciduous forests, and well
deserve their common name. In this region their presence is rarely
suspected except by hunters or others familiar with woodland life.
Far more numerous and widely known in the Western States and throughout
most of Mexico, they have adapted themselves to life under every
climatic condition, from the most sun-scorched deserts of the southwest
and the splendid redwood forests of the humid coastal region in
northern California to the tropical lowlands farther south.
They live nearly everywhere on the mountain slopes, even to timber-line
at 13,800 feet on Mount Orizaba. They thrive in an extraordinary
variety of situations, not only where they may find shelter among
rocks, but also where they must seek safety in nests made on the
surface of the ground or in burrows dug by themselves. They are
prolific animals and each year have several litters containing from two
to five young.
The presence of woodrats is generally indicated by accumulations of
odds and ends filling the crevices of the rocks about their retreats
or piled about the entrances of their burrows, such accumulations
including small sticks, pieces of bark, leaves, cactus burrs, bones,
stones, and any other small objects which may be found in the vicinity.
Sometimes these piles of fragments seem to be made merely for amusement
or to work off surplus energy, as they form useless gatherings, such as
heaps of small stones, frequently containing a bushel or more, piled
on the rounded tops of small protruding boulders in open desert areas,
or small heaps of sticks and other material scattered aimlessly about
their haunts.
In the desert where cactuses of many kinds abound woodrats’ nests are
often made at the bases of these or other thorny plants and are covered
with such a protective coating of cactus burrs as to deter the most
insistent enemy. In the heavy forests of northern California woodrats
build huge conical nests of sticks several feet in diameter on the
ground, rising to a height of five feet or more.
In southern California and elsewhere some species make great nests
of sticks eight to twenty feet from the ground in live oaks and
other trees. The stick-pile nests on the ground usually have several
entrances, with trails leading from them, and the underground burrows
usually have two or more openings.
As may be surmised from their habits, woodrats are skillful climbers,
both in trees and on the rough rock walls of the cliffs they inhabit.
Their only notes appear to be shrill squeaks and squeals when
quarreling among themselves at night. They also express annoyance or
alarm by a rapid drumming on the ground with their hind feet, just as
is done by some of the hares and rabbits.
On Santa Margarita Island, in Lower California, I found the most
curiously located habitations of these animals I have seen, the bulky
stick nests being placed well back in the midst of a mangrove thicket
growing in a tidal lagoon. At high tide the mangroves were isolated
from shore by several rods of water, so that only at low tide were the
rats able to go ashore. In going back and forth they followed certain
lines of nearly horizontal mangrove stems, the discoloration on the
bark plainly indicating the routes which finally led to dry land by
little trampled roads across the muddy ground bordering the shore.
Back a little way from shore others of the same species were living
in burrows guarded by orthodox stick and trash-pile nests among the
cactuses.
Woodrats, especially in northern localities, gather stores of pinyon or
other nuts, potatoes, corn, and any other non-perishable food available
to meet the season of storms and scarcity, concealing these supplies in
cavities in the nests either above or below the ground. They eat many
kinds of fruits, seeds, leaves, and other parts of plants, sometimes
including bark of shrubs or small trees and even cactus pads.
As a rule each nest is occupied by a single rat, but sometimes several
may be found in one, and the well-worn trails that so often connect
the entrances of neighboring nests bear evidence that woodrats have
a social disposition. In most localities woodrats are distributed
sparingly, but occasionally become so abundant in favorable places on
brushy plains that colonies containing hundreds of nests may be found
in limited areas. They sometimes become so plentiful about ranches as
to make serious inroads on grain and other crops. They also give the
Forest Service much trouble by digging up the pine seeds planted in
their great reforesting nurseries.
Woodrats are mainly nocturnal in habits and appear to be extremely
active throughout the night. Each morning in the vicinity of their
nests the light soil shows a multitude of tracks, and in places I have
seen little roads in the sand several hundred yards long which they had
made by repeated trips to a feeding ground.
No sooner is a cabin built in the mountains than they move in and
establish themselves under the floor, or locate a nest near by and use
the house as their nocturnal resort. Throughout the night the patter of
their busy feet may be heard as they race about on the floor or rustle
about the roof, and often over the sleeping forms of their unwilling
hosts.
Their activities are sources of mingled amusement and vexation. Small,
loose articles, including table knives, forks, and spoons, vanish and
all manner of trash, including horse droppings, are brought in, thus
establishing their title to the cognomen of “trade rats.” If the owner
of a cabin leaves it for a few days, he may find on his return that the
rats have taken possession and during his absence have tried to fill
it with trash of all kinds, in order to make a comfortable home for
themselves.
At one cabin in the mountains of New Mexico where I lived one summer
several mountain rats made free of the place and at night persistently
tried to add our shoes to their nest under the floor. An hour or so
after retiring we would hear our shoes scrape slowly across the floor,
and in the morning they would be found stuck toe down in the broad
crack where the floor ended near the wall. In the woodrat country when
small articles are missed from camp it is always worth the trouble to
investigate the nearest rats’ nests.
Woodrats are plentiful on the Mexican table-land, making their nests
under cactuses or thorny agaves, where they are persistently hunted as
game by the natives, who prize them as a special delicacy. I saw them
regularly sold in the markets of the cities of San Luis Potosi and
Aguas Calientes, where the method of marketing them was unique. As soon
as they were dug from their nests, their lower incisors were broken off
close to the jaw to render them powerless to bite, and then the rats
were placed alive in a strong sack and carried to town.
The vendor would sit on a curb at the market and either kill and dress
them there or shout his wares by telling every one who passed that he
had “country rats; very delicious; live ones; fat ones; very delicious;
very cheap.” The natives all praised their delicate flavor and one I
had served me as a special courtesy was really good, tasting like young
rabbit.
=THE HARVEST MOUSE= (=Reithrodontomys megalotis= and its
relatives)
(_For illustration, see page 527_)
In size, proportions, and color the harvest mice, of all our American
species, most closely resembles the common house mouse. Many of them
are decidedly smaller than that animal and they rarely, if ever, exceed
it in size. They may be distinguished from the house mouse by their
browner colors, more hairy tail and especially by a little groove which
extends down the front of each upper incisor.
The mice of this group include many species and have a wide
distribution ranging from Virginia, in the eastern United States, to
the Pacific, and from North Dakota, Montana, and Washington southward
through Mexico and Central America to northern South America.
They reach their greatest development in number and diversity of
species in the region about the southern end of the Mexican table-land,
where I have caught them from the tropical lowlands, near sea level, up
to an altitude of 13,500 feet, at timber-line, on Mount Iztaccihuatl.
[Illustration: KANGAROO RAT
_Dipodomys spectabilis_]
These delicately proportioned and graceful little beasts are habitants
of grassy, weed-grown, and brushy locations, mainly in the open
country. They are equally at home, however, in the beautiful grassy
open forests of oak, pine, and firs which clothe the slopes of the
great continental mountain system of Mexico and Central America.
[Illustration: BANDED LEMMING (_Dicrostonyx nelsoni_)