Colours of Wildlife: Wombat
Created | Updated Sep 14, 2014
Wombat
Willem is a wildlife artist based in South Africa. He says "My aim is simply to express the beauty and wonder that is in Nature, and to heighten people's appreciation of plants, animals and the wilderness. Not everything I paint is African! Though I've never been there, I'm also fascinated by Asia and I've done paintings of Asian rhinos and birds as well. I may in future do some of European, Australian and American species too. I'm fascinated by wild things from all over the world! I mainly paint in watercolours. . . but actually many media including 'digital' paintings with the computer!"
Today I make another departure to bring you a critter not from South Africa but from that other great southern land, Australia! This is a Wombat – to be precise, a Common Wombat, Vombatus ursinus. The name 'Wombat' comes from the Aboriginal Darug language. The scientific name comes from just a Latinized version of Wombat and the species name 'ursinus' means 'like a bear'. Wombats occur in southern and eastern Australia as well as in Tasmania and Flinders island. Apart from the common wombat there are two more wombat species, the Northern and the Southern Hairy-Nosed Wombats. While the common wombat has a naked rubbery patch on the front of its snout, the hairy-nosed wombats have snouts covered in soft fur. The northern hairy-nosed wombat is highly endangered, only occurring in a small patch of forest in Queensland, but there are efforts at conserving it by establishing a new colony and giving them protection against predators.
Marsupial Bear or Badger?
The wombat is somewhat bear-like. Indeed, it is a relative of the Koala Bear. But neither wombats nor koalas are at all closely related to bears. Wombats are also badger-like: early Australian settlers often called them badgers, and just about any place name in Australia bearing the name 'badger' such as Badger Creek or Badger Corner was actually named in honour of wombats rather than badgers. Real badgers don't occur in Australia.
The principal badger-like aspects of the wombat are its strong, compact body, its general toughness, and its long digging claws. An adult wombat has a total body length of about a metre/yard and can weigh 20-35 kg/45-80 lbs. Its claws come in handy since wombats dig themselves elaborate burrows. These are usually 3-4.5 m/10-15' in length but can be as much as 30m/100'. At the end of each tunnel, there is a sleeping chamber that the wombat lines with comfy tree bark. When chased by a predator, a wombat will run for its burrow. Once inside it is hard to get out. The back of its body, presented to its attacker, is covered with very tough skin. It also has a very short tail that can't be grabbed hold of. If its attacker persist, the wombat will kick at it with its strong, clawed feet, or squash its attacker's head between its back and the tunnel wall or roof.
The big difference in lifestyle between wombats and badgers is that wombats are not carnivores, but herbivores. They eat mainly grass. They have unusual teeth: they have two gnawing incisors at the front of each jaw, like the gnawing teeth of rodents. There is a long gap behind these and the grinding cheek teeth. Wombats will use the gnawing front teeth to nip off grass leaves which they then chew with the cheek teeth. They will use their strong, clawed feet to dig out grass roots. They also eat sedges, herbs, tree bark and fungi.
Furthermore, wombats are generally very relaxed and placid creatures. They live life slowly! They have a very low metabolic rate, and take very long to digest their food: a meal of grass can take two weeks from being ingested to being eliminated (interestingly, in the form of characteristic cubical faeces)! Wombats roam and feed during the night, resting in their burrows by day. They will sometimes lie just outside their burrows on sunny mornings to bask in the sun. They will sometimes feed outside on cool or overcast days. These behaviours help them regulate their body temperature, avoiding both excessive heating as well as cooling. All of this means that they don't need much energy for survival. Not needing much food, they can survive comfortably in the sparsely vegetated Australian outback. Nevertheless, wombats are absent from the more arid parts of the continent.
In spite of its general slow movements, a wombat can put on a burst of speed if necessary. When fleeing from humans, Tasmanian devils or dingoes, wombats can reach speeds of up to 40 kph/25 mph. They will fight back against attackers using their claws and teeth. They may also barrel into attackers using their sturdy bodies to bowl them over.
The major difference between wombats and badgers is that wombats are marsupials. Marsupials include most of the Australian mammals like kangaroos, koalas, bandicoots and phalangers. The opossums of the Americas are also marsupials. Marsupials are a group quite distinct from all other mammals, and very distantly related to them. Indeed, wombats are more distantly related to badgers, than badgers are related to horses, mice, whales, cats, bats, and ourselves!
Most mammals (like badgers, ourselves and others mentioned in the previous sentence) are placentals, meaning they carry their babies inside themselves for relatively long periods, feeding the unborn babies through the specialized tissue of the placenta. Marsupials don't have placentas. After being impregnated, they carry their babies inside themselves for only a few weeks or sometimes mere days. The mother's body then 'rejects' the unborn baby so to speak, and it is born in an almost unformed condition, still an embryo for all purposes. It only has a pair of reasonably well-developed forelimbs. With these, right after birth it climbs through its mother's fur towards her nipples. If it completes this perilous journey, it latches on to a nipple with its mouth and effectively fuses with it. The baby remains there for the next part of its development. Most marsupials have protective skin folds or pouches, which cover and shelter the baby for the weeks or months it will need for growth and development until it is somewhat less helpless.
The pouch of a kangaroo is well known of course, and opens towards the front. The wombat's pouch opens to the rear, because if it opened to the front, it would get full of dirt while a wombat digs its burrow! Wombat moms usually give birth to just a single baby, after a gestation of only 20 or 21 days. It remains in her pouch for six to seven months. Then it gets out and walks around by itself but still remains with its mother for another seven or eight months, after which it weans. Wombats are sexually mature at the age of eighteen months.
The other mammalian group, apart from the placentals and the marsupials, is the Monotremes, which today only include the Platypus and the Echidnas. These are unique among the mammals in laying eggs from which their young hatch. They don't have nipples either, but milk that oozes from their skin and is lapped up by their babies. Interestingly, these mammals also occur in Australia as well as Tasmania and New Guinea. Marsupials as well as Monotremes used to occur much more widely in the world, but have become extinct and replaced by placentals everywhere else.
Giant Wombats of Yesteryear
Wombats, like Koalas and kangaroos, belong to a section of the Marsupials called the Diprotodontia (meaning 'those with two front teeth'). This group was much more diverse and abundant in the past. Along with giant kangaroos and giant predators called marsupial lions (again, only extremely distantly related to true lions), there were also giant wombats and wombat relatives. These existed in a great variety of species, and ranged from only slightly larger than the modern-day wombat, to truly huge forms, Diprotodon being as large as a rhinoceros, reaching a body length of 3m/10' and a weight of over a ton. It was the largest marsupial that we know of. We still don't know exactly how these lived, or why they died out. The Diprotodon survived until relatively recent times and certainly was known to the Aborigenes before the arrival of Europeans. There are some people who believe these giant wombats inspired the legend of the strange creature called the Bunyip … indeed, a few people (cryptozoologists) believe they still survive in remote and unexplored parts of Australia! That is very, very unlikely though.
