A wallaby is any of about thirty species of Macropodidae family. It is an informal designation generally used for any macropod that is smaller than a kangaroo or wallaroo that has not been designated otherwise.
Forest-dwelling wallabies are known as "pademelons" (genus Thylogale) and "dorcopsises" (genera Dorcopsis and Dorcopsulus). The name "wallaby" comes from the Eora, who were the first human inhabitants of the Sydney area. Young wallabies are known as "joeys", like many other marsupials. Adult male wallabies are referred to as "bucks", "boomers", or "jacks". An adult female wallaby is known as a "doe", "flyer", or "jill". A group of wallabies is called a "court", "mob", or "troupe". Although members of most wallaby species are small, some can grow up to six feet in length (from head to tail).
Wallabies are herbivores whose diet consists of a wide range of grasses, vegetables, leaves, and other foliage. Due to recent urbanization, many wallabies now feed in rural and urban areas. Wallabies cover vast distances for food and water, which is often scarce in their environment. Mobs of wallabies often congregate around the same water hole during the dry season.
Their powerful hind legs are not only used for bounding at high speeds and jumping great heights, but also to administer vigorous kicks to fend off potential predators. The Tammar wallaby (Macropus eugenii) has elastic storage in the ankle extensor tendons, without which the animal’s metabolic rate might be 30-50% greater. It has also been found that the design of spring-like tendon energy savings and economical muscle force generation is key for the two distal muscle–tendon units of the Tammar wallaby (Macropus-Eugenii). Wallabies also have a powerful tail that is used mostly for balance and support. The tails are also known to knock even the strongest of predators with one tail whip
Wallabies face several threats. Wild dogs, foxes, and feral cats are among the predators they face. Humans also pose a significant threat to wallabies due to increased interaction. Many wallabies have been involved in vehicular accidents as they often feed near roads and urban areas.
Wallabies are not a distinct genetic group. Nevertheless, they fall into several broad categories. Typical wallabies of the genus Macropus, like the agile wallaby (Macropus agilis), and the red-necked wallaby (Macropus rufogriseus) are most closely related to the kangaroos and wallaroos and, size aside, look very similar. These are the ones most frequently seen, particularly in the southern states.
Rock-wallabies (genus Petrogale), rather like the goats of the northern hemisphere, specialise in rugged terrain and have modified feet adapted to grip rock with skin friction rather than dig into soil with large claws. There are at least fifteen species and the relationship between several of them is poorly understood. Several are endangered. Captive rock wallaby breeding programs like the one at Healesville Sanctuary have had some success and a small number have recently been released into the wild.
The banded hare-wallaby (Lagostrophus fasciatus) is thought to be the last remaining member of the once-numerous subfamily Sthenurinae, and although once common across southern Australia, is now restricted to two islands off the Western Australian coast which are free of introduced predators. It is not as closely related to the other hare wallabies (genus Lagorchestes) as the hare wallabies are to the other wallabies.
New Guinea, which was until fairly recent geological times part of mainland Australia, has at least five species of wallaby.
Natural range and habitat
Wallabies are widely distributed across Australia, particularly in more remote, heavily timbered, or rugged areas, less so on the great semi-arid plains that are better suited to the larger, leaner, and more fleet-footed kangaroos. They also can be found at the island of New Guinea.
Wallabies of several species have been introduced to other parts of the world, and there are a number of breeding feral populations, including:
Hawaii has small feral population of wallabies in the upper regions of Kalihi Valley of the island of Oahu arising from an escape of zoo specimens of brush-tailed rock-wallaby (Petrogale penicillata) in 1916.
In the Peak District of England, a population was established in around 1940 by five escapees from a local zoo, and as of late March 2009 sightings were still being made in the area. At its peak in 1975 the population numbered around sixty individuals.
There is also a small population on Lambay Island off the east coast of Ireland. This group was introduced by Dublin Zoo after a sudden population explosion in the mid 1980s.
Populations in the United Kingdom that, for some periods, bred successfully included one near Teignmouth, Devon, another in the Ashdown Forest, East Sussex and one on the island of Bute and Lundy. It has recently been reported by walkers in the Lickey Hills Country Park area of Birmingham that a pair of wallabies have been released or are loose there (East Tunnock Rambling Club Meeting, December 2010).
In France, in the southern part of the Forest of Rambouillet, 50 kilometres west of Paris, there is a wild group of around 30 Bennett's wallabies. This population has been present since the seventies, when some individuals escaped from the zoological park of Émancé after a storm.
Mother wallaby with joey in the Tasmanian summer rain
Three wallabies (one grey with joey in pouch, and one white) in captivity in England
As mentioned above, the term wallaby is not well defined and can mean just about any macropod of moderate size. In consequence, the listing below is arbitrary and taken from the complete list of macropods.
^Biewener, A. A.; Baudinette, R. V. (Sep). "In-Vivo Muscle Force and Elastic Energy-Storage during Steady-Speed Hopping of Tammar Wallabies (Macropus-Eugenii)". Journal of Experimental Biology198 (9): 1829–1841.Cite uses deprecated parameters (help);Check date values in: |date= (help)
^Biewener, A. A.; McGowan, C. Card, G. M. Baudinette, R. V. (Jan). "Dynamics of leg muscle function in tammar wallabies (M-eugenii) during level versus incline hopping". Journal of Experimental Biology207 (2): 211–223. doi:10.1242/Jeb.00764.Cite uses deprecated parameters (help);Check date values in: |date= (help)