HEAD OF THE RABBIT-LIKE REITHRODON.
HEAD OF THE RABBIT-LIKE REITHRODON.
The HAMSTERS, forming the sub-family CRICETINÆ, are very nearly related to the true Mice and Rats, but differ from them at the first glance by their possession of large internal cheek-pouches, those organs being entirely wanting or very small in the Murinæ. Their molars, three in number in each series, are also tuberculate when young and regularly rooted. As age advances they become more and more worn away, so as to exhibit folds of enamel. They are stoutly-built rat-like animals, generally with short tails, with the upper lip cleft, and with short limbs, of which the hinder have five, and the anterior four, toes, the thumb being represented by a small wart. The Hamsters are confined to the Old World, and chiefly inhabit the temperate parts of Europe and Asia; two or three species occur in Africa. They live generally in corn-fields, where they dig deep burrows with numerous chambers, into which they can retreat to take their repose, and in which they pass the winter, previously, however, taking care to lay up a good store of provisions in some of the chambers of their domicile.
HAMSTERS.⇒LARGER IMAGE
HAMSTERS.
⇒LARGER IMAGE
The best known species is the HAMSTER(Cricetus frumentarius,seePlate 28), a rather pretty little beast, of about ten inches long, with bright, prominent, black eyes, short, membranous ears, and a tapering hairy tail, about two inches and a half in length. The fur, which is thick and somewhat lustrous, is usually of a light yellowish-brown colour above, with the snout, the neighbourhood of the eyes, and a band on the neck reddish-brown, and a yellow spot on each cheek; the lower surface, the greater part of the legs, and a band on the forehead are black, and the feet white. Many varieties occur. This Hamster is widely distributed, ranging from the Rhine, through Europe and Siberia, to the Obi; and in most localities where it occurs it appears in great numbers, and causes great injury to the crops. Its burrows are exceedingly spacious, and consist of numerous passages and chambers. In its temper it is exceedingly irascible, and at the same time very courageous, defending itself bravely against its enemies, and standing boldly on the defensive the moment any danger appears to threaten it. Its diet is by no means of a purely vegetable nature, but it will destroy and devour all sorts of small animals that come in its way. Besides the corn, which forms its chief winter provender, green herbage, peas and beans, and roots and fruits of various kinds, are welcome articles of diet, and in confinement it will eat almost anything.
MOLAR TEETH OF THE HAMSTER.
MOLAR TEETH OF THE HAMSTER.
The Hamsters pass the winter in their burrows in a torpid state, but waken up very early in the spring, generally in March, but frequently in February. At first they do not open the mouths of their burrows, but remain for a time subsisting on the stores laid up during the preceding autumn. The old males make their appearance first, the females about a fortnight after them, the latter about the beginning of April. They then set about making their summer burrows, which are not so deep or so complicated as the winter dwellings; and shortly afterwards the sexes pair. The young are produced twice in the year, in May and July; their number varies from six to eighteen. They have teeth when first born, and their development as babies is very rapid. Their eyes open in little more than a week after birth, and in another week they begin to burrow in the ground, and then their hard-hearted parent drives them off to take care of themselves.
The other species of this sub-family generally very closely resemble the Hamster, both in appearance and manners. Most of them are found in Central Asia and Siberia, extending southwards as far as Persia and South Tartary.Cricetus songarushas been obtained at Kumaon. The recorded African species belong to two peculiar genera: they areSaccostomus lapidariusandfuscus, andCricetomys gambianus.
Other African forms constitute the small sub-family of the TREEMICE(Dendromyinæ), which are entirely confined to the southern portion of the continent. They are characterised by having the incisors rounded and grooved in front, the infra-orbital opening not narrow below, and the coronoid process of the lower jaw very small. The ears are clothed with hairs; and the feet, which are five-toed, are furnished with long claws, which are serviceable to the little rat-like animals in climbing up the trunks of trees. The BLACK-STREAKEDTREEMOUSE(Dendromys mesomelas) is a rather pretty little species, of a greyish colour, with a black line down the middle of the back. It is slender in form, with a long, scaly tail, rounded ears, and the two outer toes in each foot shorter than the rest.Steatomys pratensis, from Mozambique, is stouter in form than the preceding, and has a short, densely hairy tail; and inLophuromys ater, from the same locality, the incisors are not grooved, and the fur is developed into fine flattened bristles.
The GERBILLES(Gerbillinæ) are distinguished from all other Muridæ (although approached byHapalotis) by the great length of the hind limbs, which are converted into powerful leaping organs, somewhat as in the Jerboas and Kangaroos, although not quite to the same extent. Like all the preceding forms, they have the molars furnished with roots, but not with tuberculate crowns, these being divided into transverse plates formed by separate elliptical or rhomboidal coats of enamel. The incisor teeth are narrow, the infra-orbital opening as in the Murinæ, and the tail long and hairy.The Gerbilles are plump little animals, with a short neck, a broad head, and a pointed muzzle. The feet are five-toed, but the thumb on the fore feet is reduced to a mere wart-like process with a flat nail. They are confined to the Eastern hemisphere, and, indeed, to the African continent, the south of Asia, as far as India, and the south-east of Europe, where they live both in cultivated districts and in the driest deserts, and often occur in great numbers, when they may cause considerable damage to the neighbouring crops. They shelter themselves during the day in shallow burrows, and come forth in the evening in search of their food, which consists chiefly of grain and roots. They store up great quantities of the ears of corn in their subterranean dwellings, and in many places the poorer inhabitants search after these stores, and by digging them out procure a good supply of grain. They are very prolific, the females producing large families several times in the year.
MOLAR TEETH OF THE GERBILLE.
MOLAR TEETH OF THE GERBILLE.
Several other forms of Muridæ, with rooted molars, have been distinguished, and all are inhabitants of the Eastern hemisphere. The generaPhlœomysandNesokia, each including a single species, form the group PHLÆOMYINÆ, characterised by having broad incisors and the molars divided by transverse plates of enamel. The characters of the skull are as in the Murinæ.Phlœomys Cumingiiis from the Philippine Islands;Nesokia Griffithiiinhabits Northern India.Platacanthomys lasiurus, the only known species of the group PLATACANTHOMYINÆ, resembles a Dormouse in its form, and is nearly allied to the preceding species, but has the fur of its back mixed with long, flattened, bristle-like spines. It is a native of the Malabar coast.
SKULL OF THE WATER-MOUSE.
SKULL OF THE WATER-MOUSE.
The WATERMICE(Hydromyinæ) are of particular interest, as being a small group, exclusively confined to the Australian region, and presenting the exceptional character among the Rodents of having only two molars on each side in each jaw. These teeth, are rooted, and divided into transverse lobes by ovate enamel lobes; the front tooth is much larger than its fellow. TheHydromysare small rat-like animals of slender form, with long tails, rather densely clothed with short hairs, and short limbs. The hind feet have much stronger claws than the fore feet, and their toes are partially webbed. Five species of this group are known from Australia and Van Diemen’s Land, where they inhabit the banks of the streams. The best known are the Yellow-bellied and the White-bellied Water Mice (Hydromys chrysogasterandleucogaster), both of which inhabit New South Wales, and the latter is also found in Van Diemen’s Land. The Sooty Water Mouse (H. fuliginosus) is an inhabitant of Western Australia.
In the SMINTHINÆ—a group which includes only the genusSminthus, founded for the reception of a rat-like Rodent (S. vagus) first discovered in the Crimea, but now known to range from Hungary, Finland, and Sweden, through Russia to the banks of the Irtisch and Yenisei, and into Tartary (Bokhara)—we find another exceptional character of the molar teeth. There are four of these teeth on each side both above and below, the first and fourth of which are much smaller than the intervening ones. In this animal the ears are rather long and pointed, the legs are rather short, and the tail is about as long as the body, and clothed with short hairs.
TEETH OF SMINTHUS.
TEETH OF SMINTHUS.
In the remainder of the Muridæ, the molars, which are again only three in number on each side, are generally rootless, although occasionally the growth of the teeth stops and they close up below. The molars are composed of triangular prisms placed alternately. Two groups are thus characterised, namely, the Voles and the Zokors.
The VOLES(Arvicolinæ), which, next to the true Rats and Mice, form the most important group of Muridæ, are represented in the northern parts of both hemispheres. The brain-case in these animals is rhomboidal when looked at from above, the frontal region of the skull is much contracted, and the zygomatic arch stands out very far. The infra-orbital opening is as in the Murinæ. The molars are so constructed of alternating triangular prisms that the whole margin is enclosed by deep angular folds of enamel. These are mouse- and rat-like Rodents of a rather stout build, with the limbs and tail of moderate length, or short, and the latter more hairy than in the true Murines. The ears are short, often nearly concealed beneath the fur.
The true Voles (genusArvicola) number about fifty known species, which have been arranged by various writers under a considerable number of sub-genera, generally corresponding to differences in mode of life. Three species, representing three of these groups, are found in Britain, and may serve to illustrate the natural history of the Voles. The largest of these is the well-known WATERVOLE, or Water Rat, as it is more commonly called (Arvicola amphibius), an animal rather smaller than the Common Rat, and having, like all the Voles, the muzzle considerably blunter, and the tail a good deal shorter and more hairy. Although thoroughly aquatic in its habits, the feet of the Water Vole are not webbed; they have five toes, but the thumb in the fore feet is very short. The general colour of the fur is reddish-brown, mixed with grey on the upper surface, and yellowish-grey beneath; the ears are nearly concealed in the fur; and the incisor teeth are deep yellow in front, and very strong, presenting a considerable resemblance to those of the Beaver, to which great Rodent the Voles were formerly considered to be related. It is very widely distributed, being found in all parts of Europe, and stretching right across Central and Northern Asia, to China, the Amoor region, and the Sea of Okhotsk. In Ireland, however, it is not found. Its habits vary a little in different localities, but in general it haunts the banks of rivers, in which it burrows to a considerable distance. In the water it is very active, swimming and diving with the greatest facility, and it is here that it seeks its food, which appears to consist exclusively of vegetable substances. Professor Bell says:—“A decided preference is shown, during the summer months, for the inner or concealed part of some species of sword-flags, which is very succulent and sweet-tasted. As this portion is usually below water, the animal gnaws the plant in two near its root, when it rises to the surface, and being conveyed to some sound footing, is consumed at leisure. In default of its more favourite food, it will make a satisfactory meal on the common duckweed. Only the green and fleshy leaf is eaten, the roots and other fibrous parts being rejected. While feeding on this plant, the creature sits like a Squirrel on its haunches near the water’s edge, and taking up a lump of the soft and slimy-looking mass in its fore paws, eats a small part only, and letting the remainder fall, takes up some more in the same manner.” The accusation sometimes brought against the Water Vole of eating worms and insects, and even of destroying fish-spawn, young fishes, and even young ducks, seems to be entirely unfounded. In the winter the Water Voles will feed on turnips, mangel-wurzel, and other roots, and also upon the bark of osiers and willows, to which they do considerable damage; and in some localities they appear to frequent gardens at all seasons of the year, burrowing in the ground, and feeding luxuriously upon the produce of the gardener’s labour. Their greatest activity is in the twilight, but in quiet situations they are to be seen abroad during the day. The female produces from two to six young at a litter: twice in the year in Britain, according to Professor Bell; three or four times in the course of the summer, according to Brehm and other Continental naturalists.
MOLAR TEETH OF THE WATER RAT.
MOLAR TEETH OF THE WATER RAT.
A second British species is the FIELDVOLE, or Short-tailed Field Mouse (Arvicola agrestis), which is less than half the size of the Water Vole, and has the tail only about one-third the length of the body, instead of half that length. In the general form of the head and body the two species are a good deal alike, but the ears project farther beyond the fur in the Field Vole. The general colour of this species is greyish-brown, becoming tinged with reddish or yellowish on the sides; thelower surface is pale grey or dirty white, and the tail is brown above and greyish beneath. The Field Vole is a very abundant species in the northern and central parts of Europe, but is wanting in Ireland and south of the Alps and Pyrenees. It is usually found in damp places, especially in meadows in the neighbourhood of woods and copses, where it forms burrows of considerable extent. Its food consists almost exclusively of vegetable substances, such as roots and herbage, and in times of scarcity it will climb up trees and bushes to feed on the tender parts of the bark. In case of necessity, however, it does not disdain animal food, but will eat insects and meat, and even sometimes kill and devour smaller individuals of its own species. It breeds three or four times in the year, producing from four to six young at a birth, in a small round nest made of moss and leaves, among the roots of the herbage in some hollow of the ground. Their increase, which would otherwise be very formidable, is checked by the smaller predaceous beasts and birds, such as the Weasel, the Kestrel, and the Owls, which destroy them in great numbers. The BANKVOLE(Arvicola glareolus[53]), the third British species, which is chestnut-coloured, with white feet and with a longish tail, closely resembles the preceding species in its habits, but feeds rather on fruits and roots than on herbage, and is far more addicted to a diet of animal food, freely devouring insects, worms, snails, and even young birds and carrion. It is pretty generally distributed over Europe, but not so uniformly as the Field Vole, which it even exceeds in fecundity, the females producing from four to eight young three or four times in the year, in a nest constructed of grass and moss placed in a hollow of the surface of the ground among dense herbage.
SOUTHERN FIELD VOLE.
SOUTHERN FIELD VOLE.
The Continent of Europe is inhabited by several other species of Voles, among which we may notice the little SOUTHERNFIELDVOLE(Arvicola arvalis), which more or less completely takes the place of our common Field Vole in Southern Europe, but also extends over the whole of Central Europe, and into Western Asia. Several of these species, and others to which we cannot specially refer, ascend to considerable elevations on the mountain-sides, but at least one species,the SNOWMOUSE(Arvicola nivalis), lives on the Alps and Pyrenees, at elevations of 4,000 feet and upwards, being most abundant about the limit of perpetual snow, where it not only resides during the short period of summer, when some portion of the surface is freed from its snowy covering, but actually throughout the winter, buried under the snow, through which it makes its way in search of the roots of plants. The ROOTVOLE(Arvicola œconomus) is a large and abundant Siberian species, the range of which extends from the Obi to Kamstchatka. This and some other northern species often migrate in great bodies, after the fashion to which we shall have to refer when speaking of the Lemmings.
In North America, it would appear from Dr. Coues’ monograph, there are about a dozen distinct species of Voles. One of them, confined to the northern parts of the Continent, he identifies with theArvicola rutilusof the Old World, which he regards as a circumpolar species. South of a line running from sea to sea, a little north of the boundary of the United States, comes another form,A. Gapperi, which is regarded as a sub-species ofA. rutilus, to whichA. glareolus(seep. 116) is considered to stand in a similar relation. The most abundant North American species is the MEADOWMOUSE(A. riparius), which is distributed, apparently, over the greater part of the Continent, and takes the place of the Field Vole. On the prairies there is a peculiar species (A. austerus), a sub-species of which (A. curtatus) is found in the Western territories as far as California; the PINEMOUSE(A. pinetorum) inhabits the country east of the Mississippi; and the genus is represented in Mexico by one species (A. quasiater). The Voles are most numerous and abundant in the northern and north-western parts of North America.
Another American species is the MUSQUASH, MUSK-RAT, or ONDATRA(Fiber zibethicus), which constitutes a genus distinguished from the true Voles by having the tail compressed and nearly naked, the hinder toes united by short webs, and fringed with long hairs, and the enamel folds of the molars united by a line running down the middle of the tooth. The form of the animal is thickset, and in this respect, as in its aquatic habits, it resembles the Beaver, to which it was formerly supposed to be nearly allied. The head is short and broad, the ears project very little beyond the fur, the hind limbs are longer than the fore legs, and terminate in five toes with strong claws, while the fore limbs have only four toes and a wart-like thumb; the fur is very thick and shiny, and the colour is usually brown above and grey below, with the tail, which is nearly as long as the body, black. The fur is well known in commerce. The length of the head and body of a full-grown male is about twelve inches. The name Musk-rat, often given to this species, refers to the musky odour diffused by the secretion of a large gland situated in the inguinal region.
The Musquash, which may be described as a large Water Rat, inhabits all the suitable parts of North America, from the thirteenth to the sixty-ninth degree of north latitude, and is most abundant in the Canadian region, which offers it peculiarly favourable conditions of life in the multitude of rivers and lakes, upon the banks of which the Musquash always takes up its abode. It is a nocturnal animal, passing the day in concealment, and coming forth with the twilight to seek its nourishment, and amuse itself with its fellows. In the water it displays wonderful activity, and, in many respects, presents much resemblance to the Beaver. Curiously enough, the parallelism of habits holds good to a certain extent, even in the construction of their dwellings. The Musquash generally lives in a burrow dug out of the bank of the stream in which he disports himself, and consisting of a chamber with numerous passages, all of which open under the surface of the water. But, under certain conditions, especially in the north, he builds himself a house of a rounded or dome-like form, composed of sedges, grasses, and similar materials, plastered together with mud, and supported upon a mound of mud of sufficient height to raise it above the water. The house contains a single chamber from sixteen inches to two feet in diameter, and is entered by a passage which opens at the bottom of the water. Other passages are said to issue from this, and to lead down into the ground under the bottom of the water; these are made by the animal in his search for the roots of water-lilies and other aquatic plants, which constitute a great part of his nourishment. The Musquash also seeks provisions on land, and in this way often does much mischief in gardens. Fresh-water mussels also form a part of its diet. It passes the winter in its house, which it then furnishes with a soft bed of leaves, grasses, and sedges, and, according to Audubon, ventilates by covering the middle of the dome only with a layer of similar materials, through which the air can pass. Of the propagation of the Musquash very little seems tobe known with certainty. They pair in April and May, and the female produces from three to six young at a birth; but whether this takes place once or several times in the course of the summer is a matter of doubt. They are captured in fall-traps baited with apples, or by traps set at the mouth of their burrows. The Indians sometimes spear them in their houses.
MUSQUASH.
MUSQUASH.
The LEMMING(Myodes lemmus) is one of the most remarkable of the Muridæ, on account of the great migrations which it performs, apparently with no special object. In Norway, where it is best known, they make their appearance in the cultivated districts in such enormous numbers, and so suddenly, that the peasants have always believed them to fall from the clouds. The Lemming is a Vole-like animal, about six inches long, of which the tail makes up about half an inch. It varies considerably in colour, but is usually brownish-yellow, with dark spots above, and with a yellow streak enclosing the eye on each side of the face; the under surface is yellowish. The ears are very short, scarcely projecting beyond the fur; the eyes are small, black, and bead-like; the soles of the feet are hairy, and the claws of the fore feet much stronger than those on the hinder extremities. The Norwegian Lemmings live and breed among the peat mosses of the mountains. They are lively and active little creatures both by day and night, and feed upon the scanty vegetation of their Alpine home—grasses, lichens, the catkins of the dwarf birch, and roots. They are active even through the winter, when they make passages for themselves under the thick covering of snow which then veils the whole country, and thus are enabled to go in search of their ordinary food. They also make their way up to the surface, upon which they may occasionally be seen running, even in the depth of winter. They breed in their burrows and under stones, and must be very prolific, seeing that every predaceous animal in the country destroys and devours them. The Lemming is, in one sense, an exceedingly timid little creature, the slightest disturbance of its quietude, or even the passing over-head of a cloud, being sufficient to alarm it; but when attacked it displays themost dauntless courage, standing on the defensive against both men and animals, and biting very sharply at anything that comes within its reach. From time to time, from some unexplained cause, the Lemmings start in vast swarms from their mountain fastnesses, and make their way in a straight line in some definite direction. Nothing seems to turn them from their course; they go straight on, over hill and dale, and, although said at other times to have an aversion to water, they now swim across any lakes or rivers that come in their way. In this operation many of them lose their lives, for they require smooth water for their navigation, and the least breeze ruffling the surface suffices to send hundreds of them to the bottom. In this way they gradually arrive at the cultivated regions, where they do so much damage to vegetation, that in olden times a special form of prayer and exorcism was in use against them. Their march is accompanied by great numbers of carnivorous beasts and birds of all sorts. Wolves, Foxes, and Wild Cats, and the smaller quadrupeds of the family Mustelidæ, Eagles, Hawks, and Owls, all prey upon them with avidity—even the Reindeer is said to stamp them to death; and the story of his eating them, long discredited, has been confirmed on good authority, while man, with his Dogs and Cats, is not behindhand in the work of destruction. Nevertheless, a great multitude survives all these dangers, and, strange to say, the termination of this painful migration is always the sea, into which the survivors of the march plunge, and, apparently, voluntarily commit suicide. Mr. Crotch, who has published several papers on the Lemming and its migrations, says that in Norway these animals always proceed from the central backbone of the country in an east or west direction, and that in either case the survivors of the march drown themselves, those that go westward in the Atlantic, those that go eastward in the Gulf of Bothnia. His notion is that the migration is in obedience to an inherited instinct acquired at a time when there was land where the sea now rolls; but there are many difficulties in the way of such a hypothesis.
LEMMING.
LEMMING.
Besides the Scandinavian Lemming above noticed, several other species occur in the northern parts of the world. Three species (Myodes lagurus,obensis, andtorquatus) inhabit Siberia; the lattertwo are found in North America, the last also in Greenland. In this species, which has been placed in a distinct genus under the name ofCuniculus torquatus, the third and fourth toes of the fore feet are much larger than the second and fifth (the thumb being rudimentary), and their claws become periodically enlarged to double their ordinary size by an enormous growth during winter of horny matter on the lower surface.
The transition from this to the next family is effected by two genera, which to such an extent combine the characters of the two as to have led different zoologists to place them sometimes in the one, sometimes in the other. Externally they have all the characters of the Mole-rats of the following family; in the characters of the skull and teeth they more resemble the Voles. The ZOKOR(Siphneus aspalax), which may be taken as an example of these forms, is an inhabitant of the Altai Mountains, has the eyes very small, the external ears reduced to mere rudiments, the body cylindrical, as in the true Mole-rats, and the fore-feet armed with very long and strong claws, of which that on the fifth toe is longer than the toe itself. This animal lives in subterranean runs something like those of the Mole, but of much greater extent, and in burrowing in the earth makes use of its strong incisors to cut through the roots it meets with, and when necessary to loosen the earth. The runs pass very near the surface, and are no doubt made for the purpose of feeding on the tender roots of grasses. A species ofSiphneusis said to occur in North China. The other genus (Ellobius) includes two species; one (E. luteus) from the country about the Sea of Aral; the other (E. talpinus) from south-eastern Russia and the west of Asia. The latter abounds in the Crimea. These animals form the sub-family Siphneinæ.