Wombat

Wombats[1]
Temporal range: Pleistocene to Recent
Common Wombat, Maria Island, Tasmania
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Infraclass: Marsupialia
Order: Diprotodontia
Suborder: Vombatiformes
Family: Vombatidae
Burnett, 1829
Genera and Species

Wombats are Australian marsupials; they are short-legged, muscular quadrupeds, approximately 1 metre (39 in) in length with a short, stubby tail. They are adaptable in their habitat tolerances, and are found in forested, mountainous, and heathland areas of south-eastern Australia, including Tasmania, as well as an isolated patch of about 300 ha in Epping Forest National Park[2] in central Queensland.

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 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 faeces.

Wombats are herbivores; their diet consists mostly of grasses, sedges, herbs, bark and roots. Their incisor teeth somewhat resemble those of the placental rodents (rats, mice, moles, etc.), 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 Upper: 1.0.1.4, lower: 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 (40 in) in length and weigh between 20 and 35 kg (44 and 77 lb).

Female wombats give birth to a single young in the spring, after a gestation period, which like all marsupials can vary, in the case of the wombat: 20–21 days.[3][4] 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.[5]

Ecology and behaviour

Wombats have an extraordinarily slow metabolism, taking around 8 to 14 days to complete digestion, which aids their survival in arid conditions.[5] They generally move slowly. When threatened, however, they can reach up to 40 km/h (25 mph) and maintain that speed for up to 90 seconds.[6] Wombats defend home territories centred on their burrows, and they 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 (10 acres).[5]

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 pursuing attacker.[7] Wombats may allow an intruder to force its head over their back and then use their powerful legs to crush the skull of the predator against the roof of the tunnel, or drive it off with two-legged 'donkey' kicks.

Humans who accidentally find themselves in an affray with a wombat may find it best to scale a tree until the animal calms and leaves. Humans can receive puncture wounds from wombat claws as well as bites. Startled wombats can also charge humans and bowl them over,[8] with the attendant risks of broken bones from the fall. One naturalist, Harry Frauca, once received a bite 2 cm (0.8 in) deep into the flesh of his leg—through a rubber boot, trousers and thick woollen socks (Underhill, 1993). A UK newspaper, The Independent reported that on 6 April 2010 a 59-year-old man from rural Victoria state was mauled by a wombat (thought to have been angered by mange)[9] causing a number of cuts and bite marks requiring hospital treatment. He resorted to killing it with an axe.[10]

Species

There are three living species of wombat,[1] all of which reside only in Australia. They are protected under Australian law.[6]

Name

The name wombat comes from the now nearly extinct Darug language spoken by the Aboriginal Darug people who originally inhabited the Sydney area.[12] It was first recorded in January 1798 when John Price and James Wilson, a white man who had adopted Aboriginal ways, visited the area of what is now Bargo, New South Wales. Price wrote: "We saw several sorts of dung of different animals, one of which Wilson called a Whom-batt, which is an animal about 20 inches high, with short legs and a thick body with a large head, round ears, and very small eyes; is very fat, and has much the appearance of a badger."[13] 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.[14] The spelling went through many variants over the years including "wambat", "whombat", "womat", "wombach" and "womback", possibly reflecting dialectal differences in the Darug language.[12]

Conservation

Human impact on the wombat population is now at a critical level. Wombats suffer from a disease called sarcoptic mite or mange that was introduced to Australia and to wombats by human activity. Mites that cause mange lead to deep skin fissures that become flyblown and septic. This leads to a long, slow and painful death for wombats. In addition they are also being affected by a fungal lung disease for which there is currently no cure. Diseases and viruses brought in by farming activity now affect wombats. Incidents of Coccidia, Clostridium perfringens and tetanus amongst others, are evident in wombats. Some people believe that the distribution of mange is so widespread that only isolated populations and those tended in sanctuaries will, in the long term, survive.

It is only recently that veterinarians have begun to receive training in dealing with native animal health. Behavioural studies on wombats are few and limited in their scope. As a result, wombats are misunderstood and those attempting to rear and rehabilitate injured and orphaned wombats have difficulty getting them appropriate medical attention and in helping others understand the best ways of living with wombats.[15]

Habitat destruction is having a major impact on wombat numbers as well. Water sources and grazing areas being fenced into farms and out of public lands limits the suitable range for wombats to a small strip of land. Although Australia is a big country there are few areas where wombats can live undisturbed. They are restricted to a small section of the east coast of Australia. Unless they are fully protected, their limited distribution will reduce further. This is already evident in the northern Hairy Nose Wombat whose numbers are so low that the species is severely threatened and without human intervention will become extinct.[15]

Efforts are being made for the species' recovery. Xstrata, a Swiss global mining company, has sponsored the Xstrata reintroduction project[14], which is translocating a number of wombats to establish a new colony from Epping Forest National Park to Yarran Downs.[16]

Many parks, zoos and other tourist set-ups across Australia have wombats on public display, and they are quite popular. They can be awkwardly tamed in a captive situation, and even coaxed into being patted and held, possibly becoming quite friendly.

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 wild wombat capable of knocking an average-sized adult over, and their sharp teeth and powerful jaws can inflict severe wounds. Wombats are wide-ranging foragers and nocturnal with strong instincts for burrowing. These characteristics, besides their possible danger to humans, make them unsuitable as pets.

Unlike most other Australian marsupials, the wombat has a relatively large brain. This, combined with strong instincts upon maturity, allows a captive hand-raised wombat to be easily released into the wild.

Wombat Day

Since 2005 there has been an unofficial holiday called Wombat Day observed on 22 October, at the beginning of the traditional aboriginal spring planting season.[17]

References

Notes

  1. ^ a b Groves, C. (2005). Wilson, D. E., & Reeder, D. M, eds. ed. Mammal Species of the World (3rd ed.). Baltimore: Johns Hopkins University Press. pp. 43–44. OCLC 62265494. ISBN 0-801-88221-4. http://www.bucknell.edu/msw3. 
  2. ^ "Northern Hairy-nosed Wombat". Department of Sustainability, Environment, Water, Population and Communities. Australian Government. http://www.environment.gov.au/biodiversity/threatened/publications/northern-hairynosed.html. Retrieved 2 July 2011. 
  3. ^ Watson, A (1999). "Vombatus ursinus". Animal Diversity Web. University of Michigan Museum of Zoology. http://animaldiversity.ummz.umich.edu/site/accounts/information/Vombatus_ursinus.html. Retrieved 13 August 2010. 
  4. ^ Green, E; Myers, P (2006). "Lasiorhinus latifrons". Animal Diversity Web. University of Michigan Museum of Zoology. http://animaldiversity.ummz.umich.edu/site/accounts/information/Lasiorhinus_latifrons.html. Retrieved 13 August 2010. 
  5. ^ a b c McIlroy, John (1984). Macdonald, D.. ed. The Encyclopedia of Mammals. New York: Facts on File. pp. 876–877. ISBN 0-87196-871-1 
  6. ^ a b Humble, Gary (1 June 2006). "The Uncommon Wombat". Scribbly Gum. Australian Broadcasting Corporation. http://www.abc.net.au/science/scribblygum/june2006/. Retrieved 13 August 2010. 
  7. ^ "Common Wombat". Department of Primary Industries, Parks, Water and Environment. Tasmanian Government. http://www.dpiw.tas.gov.au/inter.nsf/webpages/bhan-53f7kj?open. Retrieved 13 August 2010. 
  8. ^ Robinson, Georgina (7 April 2010). "Wombat combat: danger is their middle name". The Examiner. http://www.examiner.com.au/news/local/news/general/wombat-combat-danger-is-their-middle-name/1796899.aspx. Retrieved 13 August 2010. 
  9. ^ BBC News (6 April 2010). "Wombat bites Australian bush fire survivor". BBC News Online. http://news.bbc.co.uk/1/hi/world/asia-pacific/8604360.stm. Retrieved 9 April 2010. 
  10. ^ The Independent (7 April 2010). "Australian Man Mauled in Rare Attack". The Independent. http://www.independent.co.uk/news/world/australasia/australian-man-mauled-in-rare-attack-by-wombat-1937850.html. Retrieved 7 April 2010. 
  11. ^ "Lasiorhinus krefftii — Northern Hairy-nosed Wombat, Yaminon". Department of the Environment, Water, Heritage and the Arts. Australian Government. 12 February 2010. http://www.environment.gov.au/cgi-bin/sprat/public/publicspecies.pl?taxon_id=198. Retrieved 13 August 2010. 
  12. ^ a b Butler, Susan (2009). The Dinkum Dictionary: The Origins of Australian Words. Text Publishing. p. 266. 
  13. ^ Reed, Alexander Wyclif (1969). Place-names of New South Wales, their origins and meanings. Reed. p. 152. 
  14. ^ a b "Common Wombat". Lady Wild Life. http://ladywildlife.com/animals/commonwombat.html. Retrieved 1 September 2008. 
  15. ^ a b www.wombatprotection.org.au
  16. ^ "Xstrata reintroduction project". http://www.derm.qld.gov.au/wildlife-ecosystems/wildlife/threatened_plants_and_animals/endangered/northern_hairynosed_wombat/xstrata_reintroduction_project.html. Retrieved 22 April 2011. 
  17. ^ Middleton, Amy (22 October 2009). "The day of the wombat". Australian Geographic. http://www.australiangeographic.com.au/society/happy-wombat-day.htm. Retrieved 13 August 2010. 

Further reading

External links