Wombat – Vombatus Ursinus
Wombats are short-legged, muscular quadrupedal marsupials native to Australia and are about 1 m (40 in) in length, with small, stubby tails. All are members of the family Vombatidae. They are adaptable and habitat tolerant, 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 (740 acres) in Epping Forest National Park in central Queensland.
Evolution and taxonomy
Though genetic studies of the Vombatidae have been undertaken, evolution of the family is not well understood. Wombats are estimated to have diverged from other Australian marsupials relatively early, as long as 40 million years ago, while some estimates place divergence at around 25 million years. While some theories place wombats as a miniaturised relatives of diprotodonts, such as the rhinoceros-sized Diprotodon, more recent studies place the Vombatiformes as having a distinct parallel evolution, hence their current classification as a separate family.
Wombats dig extensive burrow systems with their 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 soil 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 diets consist mostly of grasses, sedges, herbs, bark, and roots. Their incisor teeth somewhat resemble those of the placental rodents (rats, mice, etc.), being adapted for gnawing tough vegetation. Like many other herbivorous mammals, they have a large diastemabetween their incisors and the cheek teeth, which are relatively simple. The dental formula of wombats is 188.8.131.52.0.1.4 × 2 = 24.
Wombats’ fur can vary from a sandy colour to brown, or from grey to black. All three known extant species average around a metre 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. They have well-developed pouches, which the young leave after about six to seven months. Wombats are weaned after 15 months, and are sexually mature at 18 months.
A group of wombats is known as a wisdom.
Ecology and behaviour
Wombats have an extraordinarily slow metabolism, taking around eight to 14 days to complete digestion, which aids their survival in arid conditions. 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. 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).
Dingos and Tasmanian devils prey on wombats. Extinct predators were likely to have included Thylacoleo and possibly the thylacine. Their primary defence is their 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 rumps to block a pursuing attacker. A wombat may allow an intruder to force its head over the wombat’s back, and then use its powerful legs to crush the skull of the predator against the roof of the tunnel, or drive it off with two-legged kicks, like those of a donkey.
- Common wombat (Vombatus ursinus)
- Northern hairy-nosed wombat or yaminon (Lasiorhinus krefftii)
- Southern hairy-nosed wombat (Lasiorhinus latifrons)
More Info in WIKIPEDIA