There is evidence that the Mungo Lakes area was once the home of megafauna such as the Giant Kangaroo. This episode delves into the reasons why these very large animals no longer exist. Students will hear the different reasons why the megafauna disappeared which includes both natural and human impacts.
The megafauna mystery (5:36)
Warning – Aboriginal and Torres Strait Islander viewers are warned that the following video may contain images and voices of deceased persons.
(gleeful piano music)
[Screen reads – Question? Were humans responsible for the decline and eventual extinction of Australian megafauna?]
Ivan Johnston – Discovery Ranger, Mungo National Park
We do find lots of giant kangaroos, giant emus, and giant wombats, we have found these here in these layers of soil.
Melissa
Giant beast once roamed Willandra Lakes Region, and the rest of Australia, and much of the world. This was during the Pleistocene Epoch, between 10,000 and 2 million years ago. Most of the megafauna became extinct towards the end of the Pleistocene Epoch, with Africa the last remaining stronghold of large mammals into the modern era.
This important and worldwide wave of extinction seems to have coincided with the arrival of humans in various continents. And the role of hunter gatherers in wiping out the megafauna has been a hot topic of scientific debate. Fossils of extinct megafauna are not very common at Willandra Lakes compared to some other parts of New South Wales.
The giant species which have left their remains buried in the Willandra Lakes sediment include wombat-like, diprotodons. A short-faced, giant kangaroo, the large wallaby. Too large, Macropus kangaroos. And the genyornis, a very short, stout, flightless bird. Genyornis have been useful in working out, when Australian megafauna became extinct, because it was widespread and left numerous fossils in the form of eggshells.
Back when Australia was much wetter, genyornis and other giant flightless birds dominated the land, but as the continent grew more arid, kangaroos and other macropods took over. All genyornis eggshells have been dated to older than 46,000 years.
[Screen reads: Question? How did Indigenous Australians use fire to hunt animals?]
So, did human hunting, or widespread firing of the landscape wipe out megafauna as some researchers believe? Or was it climate change, the main factor as other scientists say.
Dr Jim Bowler – Geologist, University of Melbourne
That's a big question. It's one that is hotly debated shall we say. There is now strong evidence that there was sufficient overlap between the continuation of the megafauna and human population, so, the two overlapped for quite some time. So, the disappearance of the megafauna, there's a very strong presumptive evidence that people played a large part. Whether they were actually diminished because of human occupation is another question.
The other component is one of climate change. Now, the time that those large fauna disappeared about 45,000 years ago, was also, this is hotly debated, was also a time, when the dunes out here began to blow, big desert expansion at the same time. So, I believe it was a conjunction of both, human activity, but the change in vegetation, because these animals were browsers, they lived off the vegetation. Once you change the vegetation, you'll have to bound to impact humans, plus the big vegetation change, I think that was probably the joint answer.
Melissa
It's generally thought from the archaeological record that people first arrived in Australia about 50,000 years ago, perhaps as long as 60,000 years ago. Many of the megafauna were slow moving, and perhaps easily hunted, but they would have been vulnerable to changes in the environment also.
Harvey Johnston – Archaeologist, NSW Office of Environment and Heritage
Environments change when new elements come into them. So, when foxes or cats or dingoes, or people come to a new environment they've never been, it changes everything, it changes all the interactions. And I think that some of the extinctions are quite complex, but they're to do with that change. Some of it's to do with directly hunting and eating, some of it's to do with the ecosystem change, some of it might be do with fire change, so, I think that's a very complex area.
Melissa
However, there is little evidence to show that early Australian people hunted the big animals. The earliest signs of people at Willandra Lakes are about 45,000 years old. And preserved in their campsites are the remains of what they ate. None of the Willandra Lakes megafauna had been found in campsites. Ancient menu included shellfish, yabbies, fish, and a vast array of small mammals, including hair wallabies, bettongs, bandicoots, bilbies, and native rats.
These species could be caught in either the lake, or in the lunette burrows. Larger kangaroos are less common in the remains, but perhaps these were caught and eaten away from the lakes. Maybe megafauna too, were hunted and eaten on the plains.
Harvey
A group of people that I've worked with for a number of years have found, here at Mungo and in this region of Australia, and right across the Southern part of Australia, burnt, genyornis eggshell, which is extinct emu.
Woman
Yeah.
Harvey
And the extinct emu is burnt fragment of this, and we've got really good dates on when people were burning these fragments, these shells, and it's between 48 and 50,000 years ago, you find large numbers of these burnt genyornis eggshells. We got samples, hundreds of samples. In fact, thousands of dated samples from genyornis across Australia. (gleeful piano music continues)
List of sources and acknowledgements
Image: Recreation of mega fauna. Provided by ©Australian Postal Corporation 2008. Designer: Peter Trusler.
Image: Time line of the Pleistocene. Source image retrieved from www.wikimedia.org Megafauna from Peter Trusler.
Image: Extinct and Non Extinct Megafauna around the world.
Image: Megafauna and humans. Provided by Michael C Westaway and painted by Laurie Bernie.
Image: Magalania lizard chasing glenyornis. Retrieved from www.abc.net.au/news
Video: Building the Lake Mungo Lunette. Provided by National Parks and wildlife www.visitmungo.com.au
Image: Fire. Retrieved from www.wikimedia.com
Video: Forces shaping Willandra Lakes. Provided by National Parks and Wildlife www.visitmungo.com.au
Image: Recreation of Lake Mungo. Provided by Giovanni Caselli
Image: Human Migration Map. Source image retrieved from www.genographic.nationalgeographic.com
Image: Willandra Lake 45,000 years ago. Source image retrieved from www.donsmaps.com
Narration: Voice over by Melissa Ellis, Southern Cross School of Distance Education.
Credits
NSW Government Public Schools, Learning Systems, DART connections, Southern Cross School of Education. Virtual Excursions 2017.
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