Wombat

(Redirected from Vombatidae)

Category: Marsupials

A wombat is any of the three species of large, thick-set herbivores belonging to the family Vombatidae. Wombats are most closely related to the Koala, more distantly to the kangaroo and possum groups.

Wombats have sharp front teeth to slice off tough native grasses, and broad cheek-teeth to grind their low-grade fodder into a fine paste. Unlike those of any other marsupial, wombat teeth grow continuously — so unlike a kangaroo or wallaby, even an old wombat can still fed itself. The squat, muscular form that all wombats take is well adapted to burrowing underground. The flattened claws make effective digging instruments, and both the flattened plate of gristle over the rump and the head make useful compacting tools.

Wombats have an extraordinarily slow metabolism, taking around 14 days to complete digestion, and can survive quite comfortably on a diet that would be insufficient for most other mammals of their size. They do not move quickly unless it is essential. When required, however, they can easily out-run a human, and summon immense reserves of strength — the typical defence of a wombat against a predator underground (such as a Dingo) is to crush it against the roof of the tunnel until ribs crack or the predator stops breathing. The toughened rear hide and lack of a tail presents a difficult problem for any predator following a wombat into a tunnel.

The ancestors of modern wombats evolved sometime between 55 and 26 million years ago (dates are vague as no useful fossil record has yet been found for this period) and about 12 species flourished until well into the ice ages. The best-known of these are the diprotodons — giant wombats the size of a Hippopotamus and the largest marsupials ever known. Humans arrived in Australia while diprotodons were still common, and are believed to have played a major role in their extinction through both hunting and habitat change.

Wombats, like all the larger living marsupials, are part of the Diprotodontia, which has two suborders: the large and diverse Phalangerida (kangaroos, possums, and relatives), and the Vombatiformes (Latin for "wombat-shaped things"). Five of the seven known Vombatiforme families are extinct, only the Koala and the three species of wombat survive.

All three modern wombats are around a metre long and weigh between 20 and 35 kg.

The Common Wombat is widespread in the cooler and better watered parts of southern and eastern Australia, and in mountain districts as far north as the south of Queensland, but is declining in Western Victoria and South Australia. Common wombats can breed every two years and produce a single cub, which leaves the pouch after six to nine months but follows the mother about and breast-feeds for another year.

The Southern Hairy-nosed Wombat is found in scattered areas of semi-arid scrub and mallee from the eastern Nullarbor to the SA-NSW border area. It is the smallest wombat at around 775 to 935 mm and 20 to 32 kg, and the young often do not survive dry seasons. It is classified as vulnerable: a healthy population still remains but appears to be ageing: it is feared that the consistently sparse rainfall of recent years has prevented successful breeding. (It takes three consecutive good seasons for a Southern Hairy-nose to reach near-adulthood.) Wombat specialists are concerned that a continuation of the current trend to dryer climate in arid southern Australia could be a serious threat to the Southern Hairy-nose Wombat.

The slightly larger Yaminon, or Northern Hairy-nosed Wombat, is critically endangered. It is now restricted to a tiny range within the Epping Forest National Park in central Queensland and only an estimated 113 individuals survive.

[edit] Order Diprotodontia

• Suborder Vombatiformes
  • Family Phascolarctidae: Koala
  • Family Vombatidae
    • Common Wombat, Vombatus ursinus
    • Southern Hairy-nosed Wombat, Lasiorhinus latifrons
    • Yaminon or Northern Hairy-nosed Wombat, Lasiorhinus krefftii
• Suborder Phalangerida (about 115 species in 9 families)

[edit] See also

• The Secret Life of Wombats, James Woodford, Text Publishing, 2002, ISBN 1-877008-43-5.