Extinction

Why did the Thylacine and Tasmanian devil disappear from the mainland and why have so many mammals been lost from mainland Australia in the last 200 years?

 

Australian fauna is unlike any species found elsewhere in the world – there are no other mammals like a wombat, Tasmanian devil or Platypus!

 

Australia has unique and special fauna, same as New Guinea, where all 3 of the world’s major lineages of living mammals (Monotremes, Marsupials and Placental mammals) can be found. Monotremes occur nowhere else and the Australian/Papuan region is the global centre of such marsupial diversity.

 

Over the past 1000’s of years, there has been extinction of so many species.

Well known examples are the dinosaurs and in more recent times, the Dodo and the Tasmanian Tiger.

 

Of course there was a mass extinction of Australia’s megafauna such as the huge Wombat (Diprotodon), birds which were 3 x larger than emus like the Dromornis stirtoni, but nothing has caused the rate of loss that we are seeing today caused by us – humans.

 

When people arrived, megafauna disappeared due to increase in fire, drier climates and a change in vegetation. Recent extinctions have been attributed to many factors including habitat loss, disease, fire, European settlement, predation introduced animals such as foxes and feral cats. It’s believed that if foxes and cats had never been brought to Australia, none of the recent animal extinctions (except for the thylacine) would’ve happened

 

Australia has highest rate of mammal extinctions in the past 200 years, including the famous Thylacine or Tasmanian tiger, and unless we act swiftly, we will be adding many more to our growing extinction list!

 

Megafauna Extinctions

During Australia’s megafauna extinctions, the Australian environment changed in many ways. Extinction of Australian megafauna might have disrupted ecosystems. Many played a significant role in managing the ecosystems, like many of our existing fauna. They ate fruit and fungi and provided a very valuable ecological service, dispersing seeds and spores. They also foraged, turned the soil and dug burrows – all necessary activities to improve soil condition and help plants to regenerate. This made them all ecosystem engineers and existing native fauna, still play this significant role.

Diprotodon optatum

The massive Diprotodon optatum, from the Pleistocene era in Australia, was the largest marsupial known. It was the first fossil mammal named from Australia (Owen 1938), and one of the most well known of the megafauna. It was widespread across Australia when the first indigenous people arrived, co-existing with them for thousands of years before becoming extinct about 25,0000 years ago. (Australian Museum)

Giant Birds

The Dromornis stirtoni, was the largest of the huge, flightless birds known only from Australia. It weighed up to 500 kg and was over 3 metres tall, making it heavier than the Giant Moa of New Zealand and taller than the Elephant Bird of Madagascar. (Australian Museum)

Genyornis newton

The Genyornis newtoni was the last of the large, flightless ‘thunder birds’, endemic to Australia. It was a heavily built bird, over 2 metres tall with tiny wings and massive hind legs. If you look closely, they very much resemble our emus and cassowaries!

Thylacine (Tasmanian Tiger)

Thylacines were dog-like marsupial carnivores, whose last representative, the ‘Tasmanian Tiger’, tragically became extinct last century. The thylacine was the largest known carnivorous marsupial of modern times. It is commonly known as the Tasmanian tiger (because of its striped lower back). Native to Australia it became extinct in the 20th century. The late Miocene, Thylacinus potens, was one of the largest of the Thylacines. The thylacine was an apex predator and its closest living relative is the Tasmanian devil.