colour, and may easily be mistaken for it; then from the hind quarters
forwards they begin to assume the redder tint. As the adult Harvest
Mouse weighs only about a sixth of an ounce, it is not surprising that
it should be able to sit on an ear of corn to which its capable little
hands and prehensile tail have enabled it to climb with ease. But the
familiar name must not delude us into supposing that it is only found
in or about cornfields. It is also a denizen of the tall, rank herbage
along ditches and untrimmed hedgerows. In winter it is frequently found
about the lower parts of wheat and oat stacks.
Where the Harvest Mouse occurs it may be watched at close range by
the quiet observer. Though as a rule timid and gentle in demeanour, it
becomes at times savage and cannibalistic. It lacks the offensive odour
of the House Mouse. Its voice is of a low chirping character, and has
been likened to that of the wren.
With a more intimate knowledge of the structure of the various species
of Mice, it has been found necessary to break up the old Linnean genus
_Mus_ into several smaller genera. In this process our little Harvest
Mouse becomes the sole British representative of the genus _Micromys_.
*Wood Mouse* (_Apodemus sylvaticus_, Linn.).
An alternative name for the Wood Mouse is Long-tailed Field Mouse, and
but for the fact that Linnæus dubbed it _Mus sylvaticus_, it would be
better to adopt Pennant's designation, for it is much more an inhabitant
of the field, the hedgerow, and the garden than of the wood. It is,
indeed, the cause of something approaching despair to the keeper of the
kitchen garden; for this is the miscreant that ploughs up and eats the
newly sown peas that have not been rolled in red lead or soaked in
paraffin. He has also a great fondness for strawberries at the moment
they have become ripe.
The Wood Mouse is about three and a half inches long from the long
snout to the base of the tail; and the tail by itself falls only a
very little short of that length. The fur on the upper parts is a dark
yellow-brown; the under parts white. In adults the line of demarcation
is always distinct. There is a spot of buff or orange on the chest
whose development in certain local races has enabled recent systematists
to make five species out of this one. It has large and prominent dark
eyes--for it is chiefly of nocturnal habits--and its long oval ears have
the inner margin turned inwards at the base. The tail is dark brown
above, and whitish below. It is the commonest of the British mammals in
country places, but less frequent in Ireland. It is common in Europe as
far north as Sweden and Norway.
As a rule it constructs its burrows underground or under the roots of
trees, and here it stores up great quantities of nuts, haws, grain, and
smaller seeds for use in winter, when it becomes inactive, though it
does not really hibernate. But if there is a house handy to which it
can gain entrance in late autumn, it prefers to become the guest of
those whose garden has been a boon to it through the spring and summer.
We have had them spend the winter cosily in our rolled-up tennis
nets, stowed away in a shed to keep them dry in the off-season; and
as potatoes were stored in the same place they consumed a number of
these. On several other occasions Wood Mice were detected attempting
impudently to enter the dwelling house by the back door. Once an entire
family--mater, pater, and five active youngsters--succeeded in this
enterprise; but they left incriminating evidence of their presence,
though they were suspected of being ordinary House Mice. Accordingly a
break-back trap, baited with cheese, was set one evening, and within
half an hour its loud clap proclaimed its effectiveness. This trap
appeared to show that the Wood Mouse is a simple-minded, unsuspecting
creature, for it was reset with the same uneaten bit of cheese-rind for
bait again and again, and no sooner was the trapper's back turned than
another member of the family was secured. Seven times it sprang, and
then its inaction appeared to be due to the fact that there were no more
possible victims, for we saw no further traces of the mice. Its general
resemblance to the House Mouse frequently leads to its being mistaken
for that species.
There are several litters of young during the year, and these vary
in number from five to nine--an alarming rate of increase; but,
fortunately, the Barn Owl that hunts the hedgerow inch by inch, every
evening, takes a heavy toll that keeps the numbers down. The Fox, the
Weasel, the Hedgehog, and the Viper also do their part.
The Wood Mouse is a very active creature, running and jumping in zigzag
fashion, climbing high in the bushes in order to obtain berries, leaping
from considerable heights, and swimming well when occasion requires.
Although an accomplished excavator, it often makes use of unmortared
stone walls for its runs and stores. It wanders widely in its search
for berries, bulbs, and grain. In the matter of berries, it is not the
juicy pulp that it desires but the seeds, which it will carefully pick
out. It prefers the larger grains from the cornfield to those of a
grass-meadow. It is both timid and gentle in disposition, and on account
of its short sight, it may be approached closely and caught with the
hand.
[Illustration: _Pl. 58._ _G 90._
*House Mice.*
A fierce battle between rival males.]
[Illustration: _Pl. 59._ _G 91._
*Wood Mouse.*
Apodemus sylvaticus.]
Its stores of food are often communal, a colony of mice contributing,
for it is not always of solitary habit. These stores are of the most
varied character. Of the very miscellaneous items on its menu a few may
be mentioned: leaves of clover and dandelion, with flower-buds of the
latter, nuts of all kinds, apples, grapes, gooseberries, crocus and
hyacinth bulbs (Millais says the Dutch were taught to multiply hyacinths
by division of the bulbs through observing the effects of this mouse's
attacks), acorns, rose and bramble seeds, slow-worms, eggs and--putty!
It has been known to enter beehives, and not only to eat the honeycomb,
but impudently to construct its nest there. Deserted birds' nests are
often adapted to its use, either as a dining-room when seeking haws in
the hedges, or as a permanent habitation, in this case roofed with moss.
The breeding nest is a globular structure of dry grass, and is usually
built in a separate chamber of the underground run, but occasionally is
on the surface or under a heap of hedge _débris_. Some of the burrows
may extend as much as three feet underground.
* * * * *
Towards the end of last century, Mr. de Winton called attention to
what was considered to be a new British mouse--the Yellow-necked Mouse
(_Apodemus flavicollis_), distinguished from the Wood Mouse by its
larger size, the head and body measuring four and a quarter inches,
and the brown spot on the chest commonly found in the Wood Mouse
developed into an orange cross whose arms are connected with the upper
side coloration--described as golden brown. This is a feature that at
once attracts attention where this form occurs; but there is another
distinction out of sight--there being three additional bony joints in
the tail, that is thirty instead of the twenty-seven in the tail of
an ordinary Wood Mouse. Whether it is a really distinct species or
the typical form of the Wood Mouse is at present open to question. It
is found chiefly in the southern and eastern portions of England, but
its distribution also includes Northamptonshire, Herefordshire, and
Northumberland.
Other local races have been distinguished also as distinct species or
sub-species under the name of Hebridean Field Mouse (_A. hebridensis_)
with the white of the under parts tinted with buff; Fair Isle Field
Mouse (_A. fridariensis_), like the Yellow-necked but without the
collar; St. Kilda Field Mouse (_A. hirtensis_) with brown under parts;
and Bute Field Mouse (_A. butei_), darker, with shorter tail and ears.
*House Mouse* (_Mus musculus_, Linn.).
The most familiar, the most widely distributed and most numerous of the
mammals of our country, the Common or House Mouse, stands in little need
of nice description. Although of a timid and retiring nature, it can on
occasion exhibit not only bold familiarity, but actual friendliness to
mankind to which it has been attached for ages, preferring to live in
palace or hovel with human beings to the open-air life of woods and
fields. Not that he is not to be found in the open air; but then it is
mostly in the immediate neighbourhood of a house, where he can make his
runs in ricks of corn--mountains of food. It is this easy method of
despoiling man of his goods that caused the Mouse in ancient days to
attach himself to the huge creature that is so impotent in ridding
himself of small adversaries. The domestic Mouse is considered to have
had its home, its place of origin, in Asia, whence it has spread to
every part of the world where man has gone. In most cases, it may be
presumed with safety, it has travelled cosily stowed away in his stores
and merchandise, so that as soon as the human migrant has built himself
a home he finds that the Mouse is in occupation, and demanding a share
of his food. In spite of all his serious depredations, our literature
teems with evidence that the victim has always retained some kindly
feeling for his pretty four-footed oppressor.
For the sake of uniformity, let us say that the head and body of the
House Mouse measure a little more than three and up to four inches,
and the tapering, flexible, and sparsely haired, scale-ringed tail may
slightly exceed that measurement. It has a pointed snout, the bright,
bead-like eyes are black, the large, sensitive brownish ears are nearly
half the length of the head, and the soft, brownish-grey fur is only
a little paler on the under parts. Outdoor specimens are often more
yellow-brown in coloration. As compared with the Wood Mouse we have
this more dusky and uniform coloration, shorter whiskers, smaller eyes,
stouter and less flexible tail, and shorter legs. The thumb of the hand
is reduced to a mere tubercle.
It is very active and silent in its movements, emerging from a tiny
hole in floor-board or skirting and gliding without sound over the
floor, ascending with ease table-legs or walls, and then, if alarmed,
springing with a prodigious leap back to its hole. Concrete floors will
not suffice to keep it out of a house, for it will climb the outer walls
and enter the upper windows, thence making itself secret ways to the
lower floors behind woodwork or plastered walls, till it reaches the
kitchen, the larder or the storeroom. Though it shows by its preferences
that its natural rôle is that of grain thief, it will eat any kind of
human food and much besides: in a word, it is omnivorous.
Its great success as a species is due to this adaptability and to its
astonishing fecundity. It produces four or five litters during the
year, each consisting of five or six, or even up to twelve, blind
and naked young which develop so rapidly that in a fortnight they are
capable of independence. At the age of six weeks they may begin to
breed.
The House Mouse exhibits a considerable range of variation in colour,
both darker and lighter than the type, and many of these variations have
been bred from and their peculiarities perpetuated and accentuated in
confinement as "fancy" mice. Of these the most familiar are the White
Mice, really albinos with pure white fur, pink eyes, feet, and tail.
There are also dark, nearly black variations, and spotted examples.
Sometimes one is surprised at night to find that the house is tenanted
by a musical mouse that runs up the scale in what appears to be an
attempt at a little song. It has been ascertained, however, that these
so-called singing mice are afflicted with a form of asthma, and the
supposed vocal efforts are merely the manifestation of their physical
trouble. We have had experience of musical mice in another way. For
several nights in succession weird sounds came from the pianoforte
which suggested that fairies were using it as a harp, twanging the
wires instead of striking them with the hammers. An examination of the
interior seemed to indicate the actual performer, for a little pile
of Spanish nuts, stolen from the table, was discovered inside; and the
twanging of the notes was caused probably by the mouse climbing them. A
trap baited with a shelled nut put a stop to these performances. Bateson
mentions several cases of hairless Mice, except for a few whiskers.
A local race of the House Mouse found in St. Kilda is sometimes
dignified with species rank under the name of _Mus muralis_. Its
distinguishing features include less slender feet and tail, and
slight peculiarities of the palate.
[Illustration: _Pl. 60._ _G 94._
*House Mouse.*
Mus musculus.]
[Illustration: _Pl. 61._ _G 95._
*Alexandrine Rat.*
An alien stowaway from North Africa.]
*Black Rat* (_Epimys rattus_, Linn.).
Not many years ago a good deal of modified regret was expressed because
it was thought that the Black Rat--the real old British Rat as it was
called--was being exterminated by that vulgar upstart the Brown Rat--the
Hanoverian or Norway Rat. These laments were mainly called forth by its
comparative scarcity in old London warehouses where it had formerly been
very numerous. One would have thought it a matter for rejoicing that
there was a possibility of our having only one species of the rat pest
to contend with instead of two. The disappearance of the Black Rat was
remarked by Pennant as far back as 1778. However, later observations
tend to show that the Black Rat is far from being extinguished even in
the City of London, where the old type of warehouse is being rapidly
replaced by ferro-concrete erections with carefully trapped drains. The
intelligence of the Rat is equal to little impediments of that sort, and
if it cannot get in by way of the basement it can climb walls and enter
by the attic windows.
On the score of sentiment we need not distinguish between the Black Rat
and the Brown. They are both Asiatic aliens, though the Black Rat had
been settled here for several centuries before the Brown Rat followed
in his tracks. Nothing definite is known as to the date of his arrival.
Geologists assure us that he was not among the indigenes, for even the
most recent strata yield no remains of his bones or teeth. He is known
to have been on the other side of the dividing Channel in the thirteenth
century, and to have reached England soon after, and quickly to have
become a nuisance. He had a clear run of over four hundred years in
which to occupy the most remote portions of the island, before he had
to meet with keen competition in the form of the Brown Rat. He reached
Ireland in the twelfth century, if not earlier.
The Black Rat is of more slender proportions than the better known
Brown Rat, and much smaller, the dimensions of the head and body being
about seven inches, whilst the scaly-ringed and almost hairless tail is
more than eight inches. The long, pointed snout projects far beyond the
short lower jaw; the whiskers are long and black. Though presenting the
appearance denoted by its popular name, the glossy blue-black fur has a
good sprinkling of grey on the upper surface, whilst below it is dark
grey. The large, thin ears are naked, and about half the length of the
head. The feet are pink, with scale-like rings on the underside of the
digits and five pads on the sole. The thumb of the forefeet is reduced
to a mere tubercle.
Although the Rats have much to do with garbage and offensive matters,
they take the greatest of care to maintain their own cleanliness and a
spruce appearance, spending much of their time in cleaning their fur
and paws. One of the reasons for regretting the possible extirpation
of the Black Rat by his more pushful relative, was, no doubt, his less
ferocious ways and well-known milder disposition--a trait which is
obvious to any one who has handled the domesticated albino, or White
Rat, which is generally considered to be of this species.
Where--as in India--the Black Rat lives a more out-of-door life, it
climbs trees and mostly makes its nest in them. With us the doe collects
a good quantity of suitable materials--rags, paper, straw, etc.--and
constructs a roomy nest which she uses for successive broods, which come
at short intervals. Seven or eight is the usual number for a litter, and
there are five or six broods in a year.
In the matter of food, both the Rats are omnivorous, and it is,
therefore, useless to attempt to give a list of substances acceptable to
them. Fish, flesh, fowl, or vegetable, crustacean or mollusc--anything
that can be digested--is eaten by them; and if all else fails they will
eat their own kin. In this matter the Brown Rat, from his superior size
and ferocity, has the advantage, as is emphasised by an incident told by
a professional rat-catcher to Frank Buckland. He said that having had a
successful haul in infested premises he had turned all his captures both
Black and Brown into a large wire cage, intending to have a little sport
next day with a few cronies and a terrier or two. To his astonishment
next morning all the Black Rats had disappeared and only the Brown--or
some of them--remained.
[Illustration: _Pl. 62._ _G 96._
*Black Rat.*
Epimys rattus.]
[Illustration: _Pl. 63._ _H 97._
*Brown Rat's Nest.*
This litter of eight is a medium number.]
A sub-species, the Alexandrine Rat (_Epimys rattus alexandrinus_), with
brown back and dusky underside, is frequently introduced with shipping
from North Africa, and has been recorded from Lundy Island and Shetland.
Another sub-species, the Tree or Roof Rat (_E. rattus frugivorus_),
common in the Mediterranean region, often appears in our ports. It has
long, soft and dense fur, of light grey or brown on the upper parts and
whitish below (pure white to pale yellow), and the feet usually white
above.
The Black Rat is more of a climber than a burrower; more cleanly in its
feeding than its brown rival. The pink-skinned young are born without
fur, sight, or hearing.
*Brown Rat* (_Epimys norvegicus_, Erxleben).
The Brown Rat still has two alternative names applied to it, though the
inappropriateness of one was shown by Pennant more than 150 years ago.
These names are Norway Rat and Hanoverian Rat. Pennant does not mention
the second, but of the first he says that the Brown Rat is quite unknown
in Scandinavia and is not mentioned by Linnæus. The name Hanoverian
appears to have been given to it because it was believed to have made
its entry into England with George I. Writing in 1776, Pennant says:
"This animal never made its appearance in England till about forty
years ago." Recent researches into its distribution make it appear
that the species originated in Trans-Baikal, whence it has spread
westwards, even to America by way of the British Isles. Both species
hit upon an improved method of extending their range over the earth.
The old-fashioned natural way for mammals to spread was for a few
adventurous individuals to make food-finding excursions beyond the
district in which they were born; but climate, mountain ranges, broad
rivers or seas often checked further progress. The Rats discovered that
by keeping close to man they were always in the neighbourhood of food,
whether intended for himself or his domestic animals; and even these
tame creatures would at times serve for the Rats' meals. So when they
found man loading ships with grain and other desirable food they
decided to go with him. Often they contrived to get into his bales
of merchandise and so conveyed to the hold. If not, there were always
mooring ropes which served as bridges from the quay to the vessel. And
so they got themselves conveyed in comfort, sure that wherever the goods
went there would be settlements of their biped friends to house them and
serve their ends generally. Now, wherever man has established himself,
you are almost certain that the Rat is close at hand.
Mr. A. W. Rees, in his interesting "Creatures of the Night," has
summarised the chief characteristics of this species in a paragraph.
He says: "Brown Rats are an insufferable nuisance. There is no courtesy
or kindness in the nature of the Rat; no nesting bird is safe from his
attacks, unless her home is beyond his reach in some cleft of a rock
that he cannot scale or in some fork of a tree that he cannot climb. He
is a cannibal--even the young and the sick of his own kind become the
victims of his rapacious hunger--and he will eat almost anything, living
or dead, from the refuse in a garbage heap to the dainty egg of a
willow-wren in the tiny, domed nest amid the briars at the margin of
the river."
As compared with the Black Rat he is more heavily built, and the
combined length of head and body is eight or nine inches, whilst the
thicker, scaly-ringed tail is only equal to, or less than, the length
of the body alone. His head is proportionately shorter, with blunter
muzzle, much smaller ears and more prominent though smaller eyes. The
fur on the upper parts is grey-brown with a tawny tinge, and dirty white
on the under parts. The ears, feet, and tail are flesh-coloured. It
sometimes occurs with black or blackish fur, and is then frequently
mistaken for the Black Rat; but the relative length of tail to body is
a superficial character by which they can be separated at once. There
is a black race of this species on the east coast of Ireland to which
some authors have given the distinctive name of _Epimys hibernicus_. It
appears to have extended its range from Ireland to the Hebrides. In one
form or other the Brown Rat has extended to nearly every part of the
British Islands and their islets.
[Illustration: *Skeleton and Molars of Brown Rat.*]
The Brown Rat becomes a parent at the age of six months, and produces
four or five litters in a year. Ordinarily these consist of from four to
ten blind, deaf, and naked young; but much larger litters are on record,
the highest of which we have seen a note being twenty! Sometimes the
young grow up hairless or blind. Some years ago we disturbed a nest in
the garden from which issued half a dozen young Rats about four inches
long (head and body), all blind. They moved about in a very uncertain
manner, and were easily despatched. Similar cases have been recorded.
At the meeting of the Zoological Society in December, 1902, a hairless
Rat was exhibited on behalf of Mr. G. A. Doubleday, one of three
captured at Leyton, Essex, in the same condition. The skin, which was
slate coloured, was wrinkled into folds all over the body. Millais
mentions a hairless Rat with yellow skin.
In the country--where it is known as the Barn Rat--the Tawny Owl and the
Weasel are the farmer's best friends as Rat-catchers, though they do not
always get the consideration that their services merit. The Weasel tribe
are admittedly also destroyers of poultry; but the depredations of the
Rat in this connection are much more serious. They do much mischief in
chicken-runs, and being good swimmers and divers, even ducklings afloat
are not safe from them. If a pair of ducks have made their nest on
an island for safety, rats will swim to it and feast on the eggs, or,
should these be hatched, kill the ducklings and eat them. It is more
than probable that much of the destruction of pheasant and partridge
eggs debited to the account of the Hedgehog, has really been carried out
by the Rat. Jordan ("Forest Tithes") says he has known a Rat or Rats
take a dozen eggs from a wild duck's nest and bury them in the soft
peaty bottom of a moorland runnel, close to the nest. "I traced the
whole proceeding and dug the eggs out with my fingers."
It does not matter where it is living, in town or country, the Rat is
equally destructive to property and live stock. We have known them to
destroy a crop of garden peas by ascending the pea-sticks, night after
night, lacerating all the pods that had fair-sized peas within, and
eating out every one. They skulk along the hedgerows until they reach
the "cave" where the farmer has stored his mangolds to secure them from
frost. Scores of them will burrow through the cover of earth and eat
their fill of the succulent roots. Well is it for the farmer if the
Weasels have not been exterminated on his land, for they are the most
efficient guardians of his hoard. Hawks and Foxes render similar service
if the Rat wanders out into the open moorland; but the Rat rarely
ventures far from cover of some sort.
[Illustration: _Pl. 64._ _H 100._
*Brown Rat.*
Epimys norvegicus.]