All the members of the kangaroo family are purely vegetable feeders, and are mainly confined to Australia and Tasmania, where, before the introduction of sheep and cattle, they took the place of the ruminants of other regions. They are divided into numerous genera, of which the first includes the true kangaroos and wallabies.
The name kangaroo is said to be of Australian origin. The kangaroos and wallabies, which include the largest members of the family, are characterized by the great length and powerful development of the hind limbs as compared with the front pair; and the enormous size of the tail, which is regularly tapering, and evenly covered with fur from end to end. The true kangaroos and wallabies comprise twenty-three living species, as well as several which are extinct; and they are found not only in Australia and New Guinea, but also in some of the islands to the eastward. While the larger species are as tall as a man, the smallest do not exceed the dimensions of a rabbit. They may be divided into three groups, distinguished by size, and partly by coloration. Under the common title of true kangaroo may be included all the larger forms, characterized by their generally uniform and sombre coloration, and their large and massive skulls, in which the hinder portion of the skull is well ossified. The best known of all species is the great grey kangaroo- the "boomer", "old man", or "forester". The entire animal will weigh up to 200 pounds. It is an inhabitant of open plains, and is found over the great part of Australia and Tasmania.
As already mentioned, all the kangaroos are exclusively vegetable feeders, the larger kinds browsing solely on grass and other herbage, while many of the smaller wallabies also eat roots. Although, when feeding kangaroos occasionally move about in an awkward manner on four feet, their habitual position is the upright one, when they are supported by the hind-limbs, aided by the tail; and the whole structure of their skeleton is modified to suit this position. When an animal is resting in the usual position, with the whole of the foot applied to the ground, the knee-joint forms the summit of a solid support from which the whole body is suspended, as it were on pivots. The kangaroo can, however, raise itself so as to be supported only by the tips of the toes and the tail; and when in this position is enabled to take a wide survey of the country, and thus to obtain early warning of approaching danger. When hunting, it springs from the ground in an erect position, propelled by its powerful hind-legs and balanced by its tail, holding its short fore-arms well into the chest, after the manner of a professional runner. Thus it bounds lightly and easily along, clearing any obstacles, such as fallen trees, and even low fences, in its stride. The long tail materially assists them in running, and its measured thumps may be heard on the ground long before the kangaroo itself appears in sight in the thick forest. In general habits the kangaroo resemble sheep and deer. Timid and shy, their senses of sight, hearing, and smell are most acute. Like the hare, they appear to be unable to see an object directly in front of them while running. They are very gregarious, and are always to be met with in smaller or larger droves. Each drove frequents a certain district, and has its own particular camping and feeding-grounds. The 'mobs' do not appear to mix. Their camping-grounds are generally on some open timbered rise, and they have well-trodden runs from one ground to another. They feed early in the morning and at twilight, and also during the night. The kangaroo lies up by day, during the hot summer weather, in damp, thickly-scrubbed gullies; in the winter, on dry, sandy rises. Here, unless disturbed, they will remain quiet for hours; and it is pretty to watch a 'mob' camped up, some of them playing with each other, some quietly nibbling the young shrubs and grass, or basking in the sun half asleep on their sides. About Christmas the young ones appear to leave their mothers' sides, and congregate in 'mobs' by themselves. When on the move, kangaroos invariably follow a leader; and when once started, it is impossible to divert a drove from the direction they have taken. Except during he pairing-season, when the males engage in fierce contests, these animals are as peaceful and harmless as sheep. When hard pressed, a kangaroo will take readily to the water; and there is an instance on record of one swimming across an arm of the sea two miles in width, -half of the distance being against a strong wind and current.
There is a small kind of spike-grass, brown on the underside, called the kangaroo-grass, to which they are very partial. They will also come at night into the small bush-enclosures, and nibble off the young blades of wheat, oats, etc. When feeding off the ground, they do not always use the fore-paws as a support, but often merely crouch down. Occasionally they may be seen in the upright position, browsing from trees. As regards breeding-habits, it appears that in the great grey kangaroo the pairing-season is either in January or February, although there is some irregularity in this respect. Only a single young is prodeuced at a birth, after an exceedingly short period of gestation; and when first transferred to the pouch of its mother, the length of the offspring is scarcely more than an inch. When the young kangaroo is sufficiently developed to move freely by itself, it becomes detached from the teat to which it at first adhered; but it remains chiefly in the pouch till able to run by the side of its parent. Even then, when danger is near, it tumbles head-over-heels into the pouch for protection. The "joeys" become strong runner; and by Christmas, leave their parents and learn to shift for themselves.
