are three species of wombat;
The Common Wombat (Vombatus ursinus) is widespread and locally common from south east Queensland to Tasmanian. It is declining in Western Victoria and South Australia. Length to 1100mm, weight 20-35Kg, life span 5-15 years in wild (uncertain), longer in captivity.
The Southern Hairy-nosed Wombat (Lasiorhinus latifrons) has a patchy distribution in semi-arid scrubland and mallee from the far south east of WA to the far south west of NSW. Population classified as vulnerable due to poor breeding conditions. Length to 935mm, weight to 32Kg, life span to 12 years in wild (estimated), longer in captivity).
The Northern Hairy-nosed Wombat or Yaminon (Lasiorhinus krefftii) is critically endangered, being restricted to about 130 individuals in a 300 ha protected area in Qld. Probably the most endangered of all large mammals. Length to 1100mm, weight to 35Kg, life span as per SHN wombat. Struggling to survive because if invasion of African buffel grass which out-competes the native grasses that this wombat feeds on. Population now considered too small for relocation of enough individuals to start a new colony. Captive breeding attempts have proved largely a failure.
Wombats are part of the family of large marsupials known as the Diprotodontia. Their ancestors evolved some 55 to 26 million years ago and included the diprotodon (giant wombat), one of which was the largest marsupial to ever live, about the size of a hippopotamus. When Aboriginal Australians arrived, approximately 55000 years ago, these giant wombats were still common. It is thought that hunting and habitat alteration brought about their extinction.
Ecology and behavior
Wombat gestation is between 21 and 25 days. At birth the 2 gramme 'joey' is blind deaf and hairless. However, it has comparatively well developed forepaws and uses these, along with a good sense of smell to crawl to the mothers' pouch, whereupon it attaches itself to one of the two available teats. Here the teat will expand, keeping the infant secure. The joey will stay in the pouch for an average of 8 months, whereupon it will start to venture out on its own and will also begin to eat solids. Weaning is completed at around 20 months. Wombats will stay with their mother for the first 2-3 years of life.
Wombats have an extraordinarily slow metabolism. It takes about 2 weeks from when food is first eaten to when it is passed. This enables them to extract the maximum nutrition from their very poor diet (mainly grasses) and means they need to spend less time foraging (approx 3-8 hours per day) than a comparable sized kangaroo or ungulate. They are also able to obtain nearly all of their water requirements from plant matter and dew.
Wombats generally move slowly. However, when required the can accelerate rapidly and can reach speeds of up to 40km/h (25mph) and can maintain that speed for up to 90 seconds. This is equivalent to running 800 metres faster than an olympic athlete.
Wombats face few predators other than man. Dingoes and domestic or feral dogs will attack wombats, as will foxes and devils in Tasmania. Smaller wombats may be taken by larger birds of prey and quolls.
Wombats have developed effective defences against predators. Firstly their lower back is covered by a large cartilaginous plate which is all but impenetrable to natural predators (they also have a very short tail to aid protection when being attacked from the rear). Thus they will present their rear when under attack. If possible they will retreat to a burrow. They have been known to trap a predator underground and crush it against the tunnel roof until it is suffocated.
Wombats are thought to be relatively intelligent. Unlike koalas (their nearest relative) they have large brains which completely fill the cranial cavity. They also engage in play, thought be a sign of higher intelligence. They are, however, quite antisocial.
Wombats dig larger tunnels than any other mammal. They have remarkably strong forepaws and long claws and have been known to dig tunnels up to 30 metres (100 feet) long. They will generally rather dig through an obstacle than around it (such as fence posts) and this, coupled with the threat to stock from collapsing tunnels, has meant that in Victoria they are still regarded as vermin and often shot.
Wombats and humans
The main threat to wombat comes from mankind. The main problem is the destruction of natural habitat and the introduction of animals which compete with them for food (sheep, cattle). Many wombats are also killed on roads.
Wombats make poor pets and indeed it illegal to do so in Australia. They are usually quite passive and appear to have little fear of humans. However, this lack of fear means that they will turn aggressive if provoked, and with large incisors and strong paws they can easily inflict injuries.
The Secret Life of Wombats, James Woodford, Text Publishing 2001
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