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The wallaby is a pouched mammal that is closely related to kangaroos and are native to Australia, Tasmania, New Guinea, and a few nearby islands. Wallabies are very similar in appearance to kangaroos, except that they are usually smaller, ranging from a little more than 1 to about 4 feet in height.
Like kangaroos they also stand erect, balancing on their powerful hind legs and tail. Their young are carried in a pouch. Among the best-known wallabies are various scrub wallabies and rock wallabies, which have well-padded hind feet that enable them to hop over rock-strewn hillsides, leaping as much as 12 feet (3.7 meters). The short-tailed pademelon, unlike other wallabies, has a tail less than one-third its total length. Wallabies are classified in the order Marsupialia, family Macropodidae, subfamily Macropodinae.
Among the many exotic animals which were introduced to New Zealand, such as Red deer and chamois, there were about 12 species of wallaby. The exact number is not known because those responsible did not always bother to identify the animals they let go. In 1958 it was found that some wallaby skins from Kawan Island, some 30 miles (45 km) north of Auckland, were of the Parma wallaby. This species had once been common in New South Wales but had been extinct in Australia since the 1930s. It is now being threatened again by control measures in New Zealand to protect pine plantations.
The Dorcopsis wallabies, two species of Dorcopsis and two of Dorcopsulus, are ground dwelling but show more resemblances to the Tree kangaroos than to the remaining wallabies. They have a tapered tail which is prop-like. Behind the body it extends parallel to the ground for about one-third of its length then bends downwards to touch the ground at its tip. The Dorcopsis wallabies have functional canine teeth in the upper jaw as do the Tree kangaroos. The larger species weigh 5 to 7 kilograms but the smallest species Dorcopsulus vanheurni weighs 2 to 3 kilograms.
The Hare wallabies Lagorchestes (3 species) are small, swift wallabies of slender build weighing up to 4 kg. The Banded hare wallaby Lagostrophus fasciatus differs from other Hare wallabies, and from all remaining kangaroos and wallabies, in the structure of its incisor teeth and in the mode of union at the front of left and right halves of the lower jaw. These differences apparently reflect different feeding habits to those of other Hare wallabies. The reproductive system resembles that of kangaroo 'rats' rather than that of true kangaroos. The chromosome number is 24, two more than in any other wallaby. The Nail-tailed wallabies Onychogalea (3 species) are a little larger than the Hare wallabies and differ from them in possessing a minute horny spur (the nail) at the end of the tail tip.
The pademelons Thylogale (4 species) and Rock wallabies Petrogale (about 6 species) are a group which have, or are derived from forms with, 22 chromosomes. They are medium to small sized wallabies weighing 4.5 to 11 kilograms. The pademelons have a tapered tail whereas the Rock wallabies have an untapered tail. The hindfeet of Rock wallabies are equipped with pads and granulations and the claws are short, adaptations to rock haunting habits which are absent in the forest dwelling pademelons.
The quokka Setonix brachyurus also has 22 chromosomes but these are of different shapes from those of Rock wallabies and pademelons. The quokka is a stockily built grey-brown wallaby with a short tail and weighs 2 to 4.5 kilograms). The Little rock wallaby Peradorcas concinna is unique amongst wallabies and kangaroos in having more than four molars.
The Scrub wallabies are a group of larger wallabies with 16 chromosomes weighing up to 18 kilograms. The Scrub wallabies are widely distributed in coastal Australia sometimes being found several hundred miles inland.
The Agile wallaby Macropus agilis is of sandy-brown colour with a distinct white stripe across the thigh (hip stripe) and short ears. Bennett's wallaby Macropus rufogriseus fruticus is a large grey wallaby with a reddish tinge in the fur on shoulders and rump, an indistinct white cheek stripe and naked muzzle. It is confined to Tasmania and are distinct from the Red-necked wallaby Macropus rufogriseus banksianus of coastal eastern Australia.
The Black-striped wallaby Macropus dorsalis has a pronounced black stripe down the mid-line of its back and a distinct white hip stripe. It may not be specifically distinct from the much smaller Parma wallaby Macropus parma which may lack the hip stripe and, at best, have an abbreviated back stripe. The Black-gloved wallaby or Brush kangaroo Macropus irma is characterized by a general bluish-grey fur, the hands and feet being black. The tail has a crest of long hairs (the brush) on its upper surface.
The most beautiful of the Scrub wallabies is the whiptail or Pretty-face wallaby Macropus elegans a grey animal of slender form with a very long tapering tail. It has a distinct white face stripe from muzzle to beneath the eye. It is perhaps the most closely related of all the wallabies to the Grey kangaroo with which it will cross yielding a viable but sterile hybrid. The smallest 16 chromosome wallaby is the Tammar or Dama wallaby Macropus eugenii weighing
4.5 to 8.5 kg.
The Swamp or Black-tailed wallaby Wallabia bicolor is derived from the 16 chromosome group of wallabies but has the lowest chromosome number known in marsupials and perhaps the lowest chromosome number of any vertebrate animal. There are eight autosomes and two X sex chromosomes in female animals and eight autosomes, one X sex chromosome and two Y sex chromosomes in males. The X chromosomes are compound structures consisting of an auto-some fused to an original X chromosome. The eight autosomes of the Swamp wallaby result from union of some of the separate chromosomes of its 16-chromosome relatives into single structures. The Swamp wallaby is a sturdily built animal with coarse dark grey fur and an indistinct grey face stripe.
The Dorcopsis wallabies are confined to New Guinea. The Brown hare wallaby Lagorchestes leporides formerly inhabited dry open grassland and saltbush plains in inland southeastern Australia and may now be extinct. The remaining species survive in parts of central and northern Australia and on three small islands off the coast of Western Australia. The Banded hare wallaby formerly had a wide distribution in Western Australia but is now mainly confined to the offshore islands of Shark Bay. The Nail-tailed wallabies have also greatly diminished in numbers since European occupation of Australia but one species is still moderately abundant in tropical areas near the Gulf of Carpentaria, and in the northern parts of the Northern Territory and Western Australia.
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