Kangaroos
A kangaroo is a marsupial from the family Macropodidae (macropods, meaning 'large foot'). In common use the term is used to describe the largest species from this family, especially those of the genus Macropus, Red Kangaroo, Antilopine Kangaroo, Eastern Grey Kangaroo and Western Grey Kangaroo. Kangaroos are endemic to the continent of Australia. The smaller macropods are found in Australia and New Guinea.
Larger kangaroos have adapted much better to changes brought to the Australian landscape by humans and though many of their smaller cousins are endangered, they are plentiful. They are not farmed to any extent, but wild kangaroos are shot for meat, leather hides, sport, and to protect grazing land for sheep and cattle.
Although there is some controversy, harvesting kangaroo meat has many environmental and health benefits over sheep or cows grazed for meat.
The kangaroo is a national symbol of Australia: its emblem is used on the Australian coat of arms, on some of its currency, as well as by some of Australia's best known organisations, including Qantas. The kangaroo is important to both Australian culture and the national image and consequently there are numerous popular culture references.
The word kangaroo derives from the Guugu Yimidhirr word gangurru, referring to a grey kangaroo. The name was first recorded as "Kangooroo or Kanguru" on 4 August 1770, by Lieutenant (later Captain) James Cook on the banks of the Endeavour River at the site of modern Cooktown, when HM Bark Endeavour was beached for almost seven weeks to repair damage sustained on the Great Barrier Reef. Guugu Yimidhirr is the language of the people of the area.
A common myth about the kangaroo's English name is that 'kangaroo' was a Guugu Yimidhirr phrase for "I don't understand you." According to this legend, Lieutenant Cook and naturalist Sir Joseph Banks were exploring the area when they happened upon the animal. They asked a nearby local what the creatures were called. The local responded "Kangaroo", meaning "I don't understand you", which Cook took to be the name of the creature. The Kangaroo myth was debunked in the 1970s by linguist John B. Haviland in his research with the Guugu Yimidhirr people.
Male kangaroos are called bucks, boomers, jacks, or old men; females are does, flyers, or jills, and the young ones are joeys. The collective noun for kangaroos is a mob, troop, or court. Kangaroos are often colloquially referred to as roos.
Description
There are four species that are commonly referred to as kangaroos:
- The Red Kangaroo (Macropus rufus) is the largest surviving marsupial anywhere in the world. Fewer in numbers, the Red Kangaroo occupies the arid and semi-arid centre of the continent. A large male can be 2 metres (6 ft 7 in) tall and weigh 90 kg (200 lb).
- The Eastern Grey Kangaroo (Macropus giganteus) is less well-known than the red (outside of Australia), but the most often seen, as its range covers the fertile eastern part of the continent.
- The Western Grey Kangaroo (Macropus fuliginosus) is slightly smaller again at about 54 kg (119 lb) for a large male. It is found in the southern part of Western Australia, South Australia near the coast, and the Darling River basin.
The Antilopine Kangaroo (Macropus antilopinus) is, essentially, the far-northern equivalent of the Eastern and Western Grey Kangaroos. Like them, it is a creature of the grassy plains and woodlands, and gregarious. In addition, there are about 50 smaller macropods closely related to the kangaroo in the family Macropodidae.
Europeans have long regarded kangaroos as strange animals. Early explorers described them as creatures that had heads like deer (without antlers), stood upright like men, and hopped like frogs. Combined with the two-headed appearance of a mother kangaroo, this led many back home to dismiss them as travelers' tales for quite some time.
The first kangaroo to be exhibited in the western world was an example shot by John Gore, an officer on Captain Cook's Endeavour in 1770. The animal was shot and its skin and skull transported back to England whereupon it was stuffed (by taxidermists who had never seen the animal before) and displayed to the general public as a curiosity.
Kangaroos have large, powerful hind legs, large feet adapted for leaping, a long muscular tail for balance, and a small head. Like all marsupials, female kangaroos have a pouch called a marsupium in which joeys complete postnatal development.
Behavior
Kangaroos are the only large animals to use hopping as a means of locomotion. The comfortable hopping speed for Red Kangaroo is about 20-25km/h (13Ğ16 mph), but speeds of up to 70 km/h (44 mph) can be attained, over short distances, while it can sustain a speed of 40 km/h (25 mph) for nearly two kilometres. This fast and energy-efficient method of travel has evolved because of the need to regularly cover large distances in search of food and water, rather than the need to escape predators.
Because of its long feet, it cannot walk correctly. To move at slow speeds, it uses its tail to form a tripod with its two forelimbs. It then raises its hind feet forward, in a form of locomotion called "crawl-walking."
The average life expectancy of a kangaroo is about 4Ğ6 years.
Kangaroos In the News ...
Newly sequenced DNA - how the kangaroo got its bounce BBC - August 20, 2011
Researchers have laid bare the DNA of a kangaroo species for the first time. An international team of scientists, writing in the Biomed Central journal, Genome Biology, say they have even indentified a gene responsible for the kangaroo's hop. The group focussed on a small species of kangaroo that inhabits islands off Australia's south and western coasts. The tammar wallaby (Macropus eugenii) is only the third marsupial to have its genome sequenced. Making up the trio are the Tasmanian devil and the South American opossum.
Australia's marsupials 'have American roots' BBC - July 28, 2010
The characteristic koalas, kangaroos, possums and wombats of Australia share a common American ancestor, according to genetic research from Germany. A University of Muenster team drew up a marsupial family tree based on DNA. Writing in the Public Library of Science (PLoS) Biology journal, they suggest a single marsupial species moved from the Americas to Australia. Marsupials differ from other mammals in that mothers carry their young in a pouch after birth. As well as the familiar Australian species, the family includes the opossums and shrew opossums of North and South America, and also has a presence in Asian countries including Indonesia and Papua New Guinea.
Marsupials Not From Down Under After All Live Science - July 29, 2010
All living marsupials - such as wallabies, kangaroos and opossums - all originated in South America, a new genetic study suggests. Yep - the animals most famous for populating Australia actually started out on another continent altogether. But marsupials Ğ a group of mammals known for toting their young in belly pouches on the females Ğ are still common in South America, too. The recent study used new genetic data about some of these species to trace the family tree. The two recently sequenced marsupial genomes of the South American opossum (Monodelphis domestica) and a kangaroo, the Australian tammar wallaby (Macropus eugenii), provide a unique opportunity to apply a completely new approach to resolve marsupial relationships.
Wallaby
A wallaby is any of about thirty species of macropod (Family Macropodidae). It is an informal designation generally used for any macropod that is smaller than a kangaroo or wallaroo that has not been given some other name.
Very small forest-dwelling wallabies are known as pademelons (genus Thylogale) and dorcopsises (genera Dorcopsis and Dorcopsulus). The name wallaby comes from the Eora Aboriginal tribe who were the original inhabitants of the Sydney area. Young wallabies are known as "joeys", like many other marsupials.
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 were introduced in New Zealand, where they are seen as a pest and are often hunted. There are also a few populations of wallabies in the British Isles, the largest of which can be found on the Isle of Man where there is a breeding colony of around 100.
