From the Ground Squirrels we pass, by a perfectly natural transition, to the MARMOTS (Arctomyinæ), the second sub-family of Sciuridæ. These animals differ from the preceding forms by their broader incisors, shorter tail, and stouter form of body, and by having the third finger longer than the rest. The first upper molar, also, is larger and more persistent than in the Squirrels, and the other molars differ in structure (see figure). The Marmots are all terrestrial animals, living and storing provisions in burrows, which they dig in the ground, and they are strictly confined to the northern parts of the two hemispheres.
STRIPED SPERMOPHILE, OR GOPHER.
BURROWS OF THE PRAIRIE DOG.
The nearest approach to the Squirrels is made by the SPERMOPHILES (Spermophilus), several species of which occur in North America from Mexico to the Arctic regions, but never to the east of the great central prairie region; whilst in the Old World their domain extends from Silesia, through Russia, and across Asia, to the Amoor and Kamstchatka. The Spermophiles are Squirrel-like in form and have rather short tails, but in the American species this organ is generally longer than in those of the Eastern continent. On the thumb the claw is either very small or altogether wanting; the two series of molars are nearly parallel, and the mouth is furnished with large cheek-pouches. The ears are very small. These animals live in society, and prefer a dry, sandy, or loamy soil, in which they can easily make their burrows, which terminate in a chamber lined with grass and herbage, and have, besides, side-chambers, in which provisions can be stored for winter use. Like the other species of the family, the Spermophiles pass the winter in a state of partial torpidity. In the summer they are exceedingly lively and playful. Their food consists of roots, berries, and seeds of various kinds, and their winter stores of these articles are carried into the burrows in their large cheek-pouches. The females are very prolific, producing from four to eight young at a birth, and in some cases even as many as ten have been found. The commonest and most widely distributed of the North American species is the STRIPED SPERMOPHILE, or GOPHER (Spermophilus tredecimlineatus), a pretty little creature of from six to eight inches long, usually of a chestnut brown colour with seven yellowish-white lines running along the back and between these six rows of small squarish spots of the same colour. This species extends its range from the Red River in Canada southwards as far as Texas, and is common on the prairies east of the Mississippi. This and some other species of the genus are said to be very carnivorous in their habits, preying upon small birds and mammals; and the Gopher was even described as feeding upon the flesh of Bisons, which it found lying dead on the prairies. The other American species are more local in their distribution; four of them occur in Mexico, and one of these is only known from that country. Of the Old World species the best known is the SISEL, or SUSLIK (Spermophilus citillus), which is abundant in Central and Eastern Europe and in Siberia. Several other species are known from Asia Minor, Siberia, and Central Asia.
The BARKING SQUIRRELS, or PRAIRIE DOGS, of which two species (Cynomys ludovicianus, see figure on p. 81, and C. columbianus) are found in the United States of America, are of a stouter form than the Spermophiles, and have the ears and tail short. The claws are well developed on all the toes of the fore feet, the cheek-pouches are shallow, and the two rows of grinding teeth converge towards the back of the mouth. These animals are peculiar to North America, where the former inhabits the prairies east of the Rocky Mountains, and the latter is found on the plains of the Columbia river, and in other parts of the western territories as far south as New Mexico. The best known of the two species is the Cynomys ludovicianus, to which the name of the PRAIRIE DOG was first applied: this name being given to it from a fancied resemblance of its voice to the barking of a small Dog. It measures about a foot in length, and its tail is about four inches long. Its colour on the upper surface is reddish-brown, variegated with grey, and with a few scattered black hairs; the tail is flattened, and brownish-black towards the end, and the lower surface is brownish or yellowish-white. These animals live together in great societies, especially upon those portions of the prairies where the so-called buffalo-grass (Sesleria dactyloides) grows most luxuriantly, this grass and succulent roots constituting their chief food. They live in burrows, which they dig in the ground at a distance of twelve or fifteen feet apart; a hard-beaten path runs from burrow to burrow, and would seem to give evidence of the sociable disposition of the animals; and at the mouth of every burrow there is a little hillock, formed by the earth thrown out of it, which serves the occupant as a watch-tower. These burrows are usually so numerous upon favourable pieces of ground that the space occupied by them is quite populous, and presents a scene of considerable animation when the inhabitants are out in the pursuit of their business or their pleasure, and hence they are in common parlance spoken of as “towns” or “villages.” Their curious appearance is heightened by the almost constant presence in them of numerous small Owls, of the species known as the Burrowing Owl (Athene cunicularia), a widely-spread species, which in some places digs its own subterranean habitation, but on these prairies saves itself the trouble by taking possession of the deserted abodes of the Prairie Dogs. These birds are diurnal in their habits, and are to be seen mixed up with the Prairie Dogs in their settlements. Another inhabitant of the burrows is the Rattlesnake; and some of the earlier observers thought that the Prairie Dogs, Owls, Rattlesnakes, and some other animals, such as Horned Frogs and an occasional Tortoise, occupied the same burrow, and lived there on the most amicable footing. Unfortunately, this paradisaic picture is an imaginary one. It is true that the Rattlesnake does take up his abode in the Prairie Dog’s burrows, but he either selects a deserted one, or dispossesses, and perhaps devours, the rightful owner; and his object in his residence among the lively little Marmots is anything rather than peaceful, as they constitute his favourite food. The little Burrowing Owl has also been said by some writers to feed on the young Prairie Dogs; but this is not proved, and the food of the Owls is known to consist chiefly of Grasshoppers and Crayfish. According to the latitude in which they live, the Prairie Dogs seem to be more or less subject to torpidity during the winter.
The true MARMOTS (Arctomys) are nearly related to the Prairie Dogs. They are stout in the body, have a short tail, and a rudimentary thumb with a flat nail; and are either entirely destitute of cheek-pouches or have mere indications of those organs. The rows of molar teeth are placed nearly parallel to each other in each jaw. The skull is broad and flat above, with a depression between the orbits; and the post-orbital processes are larger than in any other Sciuridæ. The Marmots are confined to the Northern hemisphere, but over it they are widely distributed in both continents. Of the Old World species, the best known are the BOBAC (Arctomys Bobac) and the ALPINE MARMOT (A. Marmota), of which the former extends from the south of Poland and Galicia over the whole of Southern Russia and Siberia to the Amoor region and Kamstchatka, whilst it is found in elevated situations as far southward as Cashmere, Tibet, and the Himalayas; and the latter inhabits only the higher regions of the Alps, Pyrenees, and Carpathians. In North America the common species is the WOODCHUCK (Arctomys Monax), the distribution of which is from the Carolinas northward to Hudson’s Bay, and westward from the Atlantic coast to Missouri, Iowa, and Minnesota; the Rocky Mountain region is inhabited by a distinct species (A. flaviventer); and a third very large species, the HOARY MARMOT, or WHISTLER (A. pruinosus), which measures from twenty-three to twenty-five inches in length of body, appears to be most abundant in the north-western parts of the continent, and is said to range northward as far as the Arctic Circle. The Marmots live usually in large societies in extensive burrows, which they form underground; and in some localities, as on the great plains of Russia and Siberia, their dwelling-places are described as producing a remarkable effect, owing to the multitude of little hillocks formed by the earth thrown out of their burrows. During the summer they are in a state of constant activity, playing and running about in search of food in the neighbourhood of their dwellings. The winter they pass in a state of torpidity, in a comfortable chamber lined with soft herbage, and protected from the outside cold by the closure of the main passage leading into their abode. For a time after their retirement for the winter they continue active in their domicile, and feed upon the stores of food which they have laid up during the summer; and as a preparation for their winter sleep, they become exceedingly fat during the autumn. The Marmots are the largest members of their family, and, indeed, some of them may be reckoned among the larger Rodents. The Alpine Marmot measures more than twenty inches in length, and the Bobac about fifteen inches, exclusive of the tail.
ALPINE MARMOT.