Wombat

Wombats[1]
Fossil range: Pleistocene to Recent
Common Wombat in the snow
Common Wombat in the snow
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Infraclass: Marsupialia
Order: Diprotodontia
Suborder: Vombatiformes
Family: Vombatidae
Burnett, 1829
Genera and Species
  • Vombatus
    • Vombatus ursinus
  • Lasiorhinus
    • Lasiorhinus latifrons
    • Lasiorhinus krefftii
  • †Rhizophascolomus
  • †Phascolonus
  • †Warendja
  • †Ramasayia

Wombats are Australian marsupials; they are short-legged, muscular quadrupeds, approximately 1 metre (39 in) in length with a very short tail. They are found in forested, mountainous, and heathland areas of south-eastern Australia and Tasmania. The name wombat comes from the Eora Aboriginal community who were the original inhabitants of the Sydney area.

Contents

Characteristics

Wombats dig extensive burrow systems with rodent-like front teeth and powerful claws. One distinctive adaptation of wombats is their backwards pouch. The advantage of a backwards-facing pouch is that when digging, the wombat does not gather dirt in its pouch over its young. Although mainly crepuscular and nocturnal, wombats will also venture out to feed on cool or overcast days. They are not commonly seen, but leave ample evidence of their passage, treating fences as minor inconveniences to be gone through or under, and leaving distinctive cubic scat.

Wombats are herbivores, their diet consisting mostly of grasses, sedges, herbs, bark and roots. Their incisor teeth somewhat resemble those of the placental rodents, being adapted for gnawing tough vegetation. Like many other herbivorous mammals, they have a large diastema between the incisors and the cheek teeth, which are relatively simple. The dental formula of wombats is:

Dentition
1.0.1.4
1.0.1.4

Wombats' fur colour can vary from a sandy colour to brown, or from grey to black. All three known extant species of wombats average around 1 m (39 in) in length and between 20 and 35 kg (44 and 77 lb) in weight.

Female wombats give birth to a single young in the spring, after a gestation period lasting 26–28 days. They have a well-developed pouch, which the young leave after about 6–7 months. Wombats are weaned after 15 months, and are sexually mature at 18 months of age.[2]

Ecology and behaviour

Wombats have an extraordinarily slow metabolism, taking around 14 days to complete digestion, which aids their survival in arid conditions.[2] They generally move slowly, but when threatened they can reach up to 40 km/h (25 mph) and maintain that speed for up to 90 seconds. Wombats defend home territories centred on their burrows, and react aggressively to intruders. The Common Wombat occupies a range of up to 23 ha (57 acres), while the hairy-nosed species have much smaller ranges, of no more than 4 ha (9.9 acres).[2]

Dingos and Tasmanian Devils prey on wombats. The wombat's primary defence is its toughened rear hide with most of the posterior made of cartilage. This, combined with its lack of a meaningful tail, makes it difficult for any predator that follows the wombat into its tunnel to bite and injure its target. When attacked, wombats dive into a nearby tunnel, using their rump to block a perusing attacker. They can even crush a predator against the roof of the tunnel.[3]

Evolution

Wombats, like all the larger living marsupials, are part of the Diprotodontia. The ancestors of modern wombats evolved sometime between 55 and 26 million years ago (no useful fossil record has yet been found for this period). About 11 species flourished well into the ice ages. Among the several rhinoceros-sized Giant Wombat (Diprotodon) species was the largest marsupial to have ever lived. The earliest human inhabitants of Australia arrived while diprotodons were still common. The Aborigines are believed to have brought about their extinction through hunting, habitat alteration, or probably both.

Species

There are three living species of wombat:[1]

Wombats and humans

Wombats were often called badgers by early settlers because of their size and habit. Because of this localities such as Badger Creek, Victoria and Badger Corner, Tasmania were named after the wombat.[6]

The town Wombat, New South Wales, the asteroid 6827 Wombat, a soccer team in Brisbane and the British anti-tank rifle L6 Wombat (by an awkward acronym) are named after the animal.

They can be awkwardly tamed in a captive situation, and even coaxed into being patted and held, possibly becoming quite friendly. Many parks, zoos and other tourist set-ups across Australia have wombats on public display, and they are quite popular. However, their lack of fear means that they may display acts of aggression if provoked, or if they are simply in a bad mood. Its sheer weight makes a charging wombat capable of knocking an average-sized man over, and their sharp teeth and powerful jaws can result in severe wounds. The naturalist Harry Frauca once received a bite 2 cm (0.79 in) deep into the flesh of his leg—through a rubber boot, trousers and thick woollen socks (Underhill, 1993).

Gallery

Further reading

References

  1. ↑ 1.0 1.1 Groves, C. (2005-11-16). Wilson, D. E., and Reeder, D. M. (eds). ed.. Mammal Species of the World (3rd edition ed.). Johns Hopkins University Press. pp. 43-44. ISBN 0-801-88221-4. http://www.bucknell.edu/msw3. 
  2. ↑ 2.0 2.1 2.2 McIlroy, John (1984). Macdonald, D.. ed.. The Encyclopedia of Mammals. New York: Facts on File. pp. 876–877. ISBN 0-87196-871-1. 
  3. ↑ http://www.dpiw.tas.gov.au/inter.nsf/webpages/bhan-53f7kj?open
  4. ↑ http://animaldiversity.ummz.umich.edu/site/accounts/information/Lasiorhinus_krefftii.html
  5. ↑ http://www.arkive.org/species/GES/mammals/Lasiorhinus_krefftii/more_info.html
  6. ↑ Lady Wild Life, Common Wombat, http://ladywildlife.com/animals/commonwombat.html, retrieved on 2008-09-01 

External links