threatened species

Possum Tragic: Victoria's Vanishing Vertebrate

Deep in the Australian bush, a pair of possums set out on an adventure that will take them across the continent. Grandma Poss makes her granddaughter Hush invisible to keep her safe from predators, but when Hush decides she wants to be seen, Poss must work her bush magic to make her visible again.

Possum Magic, written by Mem Fox and illustrated by Julie Vivas, first appeared on shelves more than thirty years ago. Over the course of three decades this charming piece of children’s literature has worked its way into the country’s collective imagination. With a magical narrative and a host of native characters, Possum Magic has become a pivotal part of childhood in Australia.

Yet this whimsical tale of a disappearing possum is not as far from reality as we may think. Though species like Ringtail and Brushtail Possums are a common sight in Melbourne’s parks and gardens, elsewhere in Victoria their relative, the mountain pygmy possum, is in danger of extinction.

The mountain pygmy possum is just one species currently under threat of extinction.  Image: Matt West

The mountain pygmy possum is just one species currently under threat of extinction. Image: Matt West

At Mount Buller, one of only three populations of mountain pygmy possum in the world is dwindling to invisibility. Australia’s only hibernating marsupial measures up to 29cm from the top of its head to the tip of its tail, and weighs between 30 to 60 grams. Confined to alpine and subalpine regions due to their dependence on winter snow, there are very few populations left in Australia (two in Victoria and one in New South Wales) and less than 2,000 individuals remaining today.

Hibernation is a vital part of life for the mountain pygmy possum.   Image:   Matt West

Hibernation is a vital part of life for the mountain pygmy possum.  Image: Matt West

In 1996, it was estimated that there were 300 adult female mountain pygmy possums at Mount Buller. Over the years their population has fallen rapidly, and in 2007 it was estimated that there were as few as 30 adults surviving. Habitat destruction is one of the key reasons for the dramatic decline in their numbers; the growth of the ski resort at Mount Buller, for example, has negatively impacted on the mountain pygmy possum population. Climate change is affecting snowfall and disrupting hibernation, while wildfires are damaging to their habitats.

This species is now estimated to inhabit a total range of less than seven square kilometres. As the snowline recedes across the country, their numbers continue to fall. Surprisingly, the first record of the species was discovered in 1894: a fossil found in the Wombeyan Caves, New South Wales. For the best part of a century, it was the only evidence that the creatures had ever existed. A living specimen wasn’t found until 1966. Now, nearly fifty years later, we are on the brink of losing them forever. Like Grandma Poss, we need to work some bush magic before our possums vanish completely.

Let us hope that the unique mountain pygmy possum does not disappear like little Hush.  Image: Julie Vivas

Let us hope that the unique mountain pygmy possum does not disappear like little Hush. Image: Julie Vivas

Mem Fox’s earlier drafts of her most famous work featured mice in the leading roles. It wasn’t until late in the process that Hush and her Grandma became possums. Would the tale of Hush the vanishing mouse have become as integral to the Australian psyche? Likely not. The true value of Mem Fox’s and Julie Vivas’ work is to be found not only in the telling of a magical and memorable story, but in reminding children and adults that there is magic to be found in the bush.

 

Banner image courtesy of Julie Vivas

 

The Extinction Of The Thylacine: A Cautionary Account

The thylacine sounds like something out of a children’s book: it was an animal with the body of a dog, a kangaroo’s tail, a pouch, and stripes from its shoulders to its tail. It is said to have had an awkward gait and was rarely seen to move quickly, yet it was a proficient carnivore, preying upon a variety of marsupials under the cover of darkness. Thylacinus cynocephalus (dog-headed pouch-dog), also known by its more common name the Tasmanian tiger, was once an apex predator throughout mainland Australia, Tasmania and New Guinea.

This unusual creature is an excellent example of convergent evolution, which occurs when two unrelated species are put under similar evolutionary pressures and exist in a similar ecological role, producing two species that possess similar features. In other words, similar problems produce similar solutions. Although the thylacine superficially resembled members of the family Canidae (such as wolves and dingoes) with its sharp teeth, raised heels, muscular jaws and dog-like body form, its marsupial pouch, kangaroo-like tail and relatively short legs point towards the fact that this species is only distantly related to its canine doppelgangers. It was the only extant member of the family Thylacinidae, its closest relatives being the Tasmanian devil and the numbat.

One of the few photographs taken of the last thylacine, a resident of Hobart Zoo.  Photo courtesy of Australian Museum.

One of the few photographs taken of the last thylacine, a resident of Hobart Zoo. Photo courtesy of Australian Museum.

The modern thylacine evolved around four million years ago, and although it had previously been found throughout continental Australia, it became extinct on the mainland at least two thousand years ago. The mainland extinction was possibly due to competition with dingoes. However, this is arguably related to the two species’ opposing lifestyles: dingoes typically hunt during the day, whilst thylacines were mostly nocturnal.

The thylacine's last stronghold was the island of Tasmania, but the arrival of Europeans to Tasmania in 1803 spelled the beginning of the end for the marsupial carnivore. When sheep were introduced to the island in 1824, the thylacine began to gain notoriety among farmers as the culprit responsible for attacks on livestock. While Tasmanian tigers would have had some effect on the growing population of sheep on the island, their impact was greatly exaggerated. One infamous photo of a Tasmanian tiger with a chicken in its mouth is now thought to have been staged, with the photographer likely to have created the scene by placing a dead chicken in the mouth of a taxidermied thylacine. Due to the hype surrounding its apparent effect on livestock, a bounty was placed on the thylacine, with the Tasmanian government paying one pound per head. Between 1888 and 1909, over 2184 bounties were paid out to farmers and hunters alike.

The infamous image of a thylacine with a chicken in its mouth - most likely staged.  Photo courtesy of Australian Geographic.

The infamous image of a thylacine with a chicken in its mouth - most likely staged. Photo courtesy of Australian Geographic.

By this time, hunting had taken its toll on the species. Thylacine sightings became infrequent, and zoos around the world sought after the strange animal. Still, the extermination undertaken by farmers and hunters continued. The last known wild thylacine was shot by farmer Wilf Batty in 1930, and then finally, the last captive thylacine died in Hobart Zoo on the 7th of September, 1936. Only then, once the last known Tasmanian tiger had perished, was it placed on the threatened species list. Ultimately, having not been seen in the wild for fifty years, the thylacine was declared extinct in 1986. In addition to the hunting pressure brought about by humans, the demise of the thylacine has been attributed to habitat loss, competition with dingoes and introduced wild dogs, and the concurrent demise of its prey species.

The extinction of this mysterious marsupial is commemorated every year on Threatened Species Day, which falls on the 7th of September: the day that the last known Tasmanian tiger died. Now more than ever is the loss of the thylacine relevant to the struggles we face in trying to combat the extinction of our native animals, and should serve as a reminder not to take our unique wildlife for granted. Victoria is home to an array of species that not only fascinate and inspire, but also play an integral role in their respective ecosystems. Personally, I would have treasured a sighting of a Tasmanian tiger in its natural environment, but sadly this is something that I and countless others will never experience. We need to rally behind our native wildlife today so that as we grow old, we will not look back and wish we had done more.

Australia has the worst mammalian extinction rate of any country in the world, having lost 29 species over the past two centuries. I wonder, what is in store for the next 200 years?

A combination of all known video footage of the thylacine. Courtesy of The Thylacine Museum.

Banner image courtesy of Joseph Gleeson (painter)