Buzz
Australia is renowned for its diverse wildlife, many of which appear to have emerged from the depths of imagination. Among these, one group stands out for its unique characteristics: the marsupials. Originating in South America, marsupials have found a unique home in Australia, where they have become iconic. Here are some reasons why.
10. Marsupial Offspring
Marsupials are distinguished by their pouches, into which their newborns crawl after just a couple of weeks’ gestation. This unusual setup has given marsupials some odd features during early development. There’s a particular order of growth that’s common among all vertebrate embryos—that is, most mammals, amphibians, reptiles, fish, and birds. The major internal organ systems come first, then the limbs follow. Marsupials have evolved a different order, in which limbs are the first parts to develop. This is necessary so the newborn can crawl into its mother’s pouch when it’s born so early.
The early birth of marsupial babies has created a unique (and only) mammal that is known to breathe through its skin. The babies of the Julia Creek dunnart, a marsupial mouse, are delivered from the womb after only 12 days of gestation. Their lungs are too underdeveloped to be useful, so they take in all of their oxygen directly through the skin. The lungs take over gradually, and are contributing about half of a baby’s oxygen after three weeks in the pouch.
9. Wallabies On Drugs
Koalas are often accused of being intoxicated by their diet of eucalyptus leaves, but that’s actually a myth. Koalas are just so lazy that they merely appear to be on drugs. The real addicts of the marsupial world are the wallabies of Tasmania.
Tasmania is the world’s largest producer of poppies for legal opiates, and the tens of thousands of acres of plants have caught the attention of the local skipping critters. They turn up, munch, and then spend the day walking around in a daze. The stoned wallabies (a great band name that’s already been taken, we’re afraid) tend to spiral about the place, and leave crop circles in their wake.
8. The Hammer-Toothed Snail Eater
When scientists uncovered a fossil in Queensland, Australia, they were puzzled. The fossil was a marsupial, about the size of a ferret. Yet its teeth were unlike any known in other mammals. It had a large, blunt tooth on each side of its upper jaw, shaped like the head of a hammer. Teeth are a good clue to diet, so what did this newly discovered creature (dubbed Malleodectes) eat?
The answer came from Dr. Scott Hocknull, from Queensland Museum. He noticed the teeth resembled those in an Australian lizard, the pink-tongued skink. The lizard uses its hammer teeth to crush snail shells. The newly found marsupial is no more related to the lizard than we are. Both animals evolved the same solution independently—snails are just that tasty.
7. The Gilbert’s Potoroo
The Gilbert’s potoroo is the world’s rarest marsupial. For 120 years people thought it had gone extinct, until 1994. Forty of the rodent-like creatures (it’s nicknamed “rat kangaroo”) were found that year at Two Peoples Bay Nature Reserve, near Albany. The area was due for urbanization, until Prince Philip, husband of Queen Elizabeth II, campaigned to protect the area due to the noisy-scrub bird. Curiously, that bird was thought to have been extinct, until it was found alive in 1961, prompting conservation efforts and inadvertently saving the potoroo.
The potoroo is still critically endangered. A captive breeding facility has been set up to keep it away from predators, and some have been released to the wild. Cats, foxes, and other animals are a major threat. Conservationists are hoping to learn enough about the potoroo to be able to find other suitable sites, where it might have a better chance to survive and—maybe one day—thrive.
6. Kangaroo Adoption
The pouch is the quintessential feature of marsupials, serving as both a womb and an early-life carry-cot. This unique adaptation ensures the survival of their young. Researchers at Wilsons Promontory National Park were astonished to observe a mother kangaroo adopting another female's joey. Remarkably, the original mother accepted the now orphaned joey, leading to a complete swap between the two mothers.
This behavior marks the first documented instance of such adoption in the wild, though similar occurrences have been noted in captivity. Intriguingly, the adoption was permanent; the kangaroos nurtured their new offspring as their own. Subsequent studies revealed four instances of joey swaps and three adoptions, with no clear familial ties between the involved kangaroos.
Researchers hypothesize that these adoptions may result from kangaroos being overwhelmed by predators, leading to misidentification of their own young in moments of panic. While the exact cause remains uncertain, this phenomenon underscores the complexity of kangaroo social behaviors and the importance of not assuming that a joey in a pouch is related to the kangaroo carrying it.
5. Djarthia and the Little Mountain Monkey
As previously mentioned, marsupials actually trace their origins to South America. One species migrated to Australia around 55 million years ago, giving rise to all the marsupials there today, including koalas, kangaroos, and wombats. This pioneering creature, similar to a mouse, is known as Djarthia.
Interestingly, some of Djarthia’s early descendants may have returned to South America. The little mountain monkey, also called Monito del Monte, is a small tree-climbing marsupial found in the forests of Chile and Argentina. Scientists had long suspected that it might be more closely related to Australia’s marsupials than to its South American relatives, and the discovery of Djarthia fossils in 2008 has made this theory almost certain.
4. Wombat Poo
Animals have a variety of ways to mark their territory. While we are most familiar with scent marking through urination, wombats take it a step further by using their feces. They leave small piles of droppings wherever they want to assert their dominance, often on rocks, logs, and even mushrooms.
The issue with most animal droppings is that they can easily roll away, but wombats have solved this by producing their scat in the form of small cubes. Each bowel movement results in four to eight of these pellets, which they strategically place around nose-height so other wombats are sure to notice. The feces are coated with a sticky mucus and have a smell described as 'sweet' and 'peaty.'
You might not be thinking, 'Wombat feces sounds awesome, can I get some?' but surprisingly, you can. An Australian souvenir company sells paper made from wombat droppings. They started by making paper from kangaroo waste, but after customer requests, they began producing wombat-poo paper, which is now the most popular. The paper is made by boiling the poop and processing the fibrous pulp.
3. Koala Grunts
When you hear the word 'koala,' do you think 'aw'? If not, perhaps you’re missing the koala charm (or maybe it’s because we told you that they eat their mother's poop). Despite their cuteness, male koalas produce a grunt that resembles the sound of an old motorcycle struggling to start. It's commonly believed that this grunt is used to ward off other males who have ventured into the grunter's territory.
To understand the koalas' vocalizations, Dr. Bill Ellis and his team equipped several with GPS trackers and observed their responses to various calls. They discovered that the distinctive grunts are primarily used by males to attract females, rather than to deter rivals. Additionally, young koalas emit a 'yip' when separated from their mothers, prompting the mothers to retrieve them.
Despite their endearing appearance, koalas' grunts were utilized in the production of 'Jurassic Park' as the vocalizations for the T. rex.
2. Feral Wallabies
If you're interested in observing wallabies, there's no need to travel to Australia. You can visit Scotland, where a population of up to 60 has inhabited an island in Loch Lomond since the 1940s. These wallabies have become a popular tourist attraction, though local conservationists advocate for their culling due to their consumption of vegetation that sustains native wildlife.
Scotland is not the only place wallabies have made their home. The Peak District in Southern England once hosted a population of them, having been released in 1940 after private zoos were banned in the UK. Their numbers peaked at 50, but a harsh winter in 1963 cut their population in half, and they never fully recovered. The last known female wallaby was seen alive in 2009. A similar group was introduced in Hawaii, but they likely also became extinct.
1. Chlamydia Is Devastating Koalas
Koala populations in Australia are in decline. Various factors contribute to this, including habitat loss, dog attacks, and vehicle collisions, but perhaps the most devastating threat is chlamydia. In some areas, up to 90% of koalas are infected, and the disease is both unpleasant and dangerous. It can lead to blindness, infertility, and even death. Koala chlamydia can be treated with antibiotics, just like in humans, but the koala hospitals are struggling to keep up. These animals seem especially vulnerable to the disease, and the reason remains unclear.
Hope remains, though. Researchers are working to better understand the koala's immune system, including by mapping its genes. Early findings have shown promise, and vaccine trials are underway. Australia's wildlife, including koalas, contributes $1 billion to the tourism economy, so the efforts to save them have widespread support.
