Humans, Not Climate Change, Wiped Out Australian Megafauna (phys.org)

"New evidence involving the ancient poop of some of the huge and astonishing creatures that once roamed Australia indicates the primary cause of their extinction around 45,000 years ago was likely a result of humans, not climate change," reports Phys.org. schwit1 quotes their report on new analysis of a prehistoric sediment core from the Indian Ocean off the coast of Australia. The core contains chronological layers of material blown and washed into the ocean, including dust, pollen, ash and spores from a fungus called Sporormiella that thrived on the dung of plant-eating mammals, said CU Boulder Professor Gifford Miller, who participated in the study... Fungal spores from plant-eating mammal dung were abundant in the sediment core layers from 150,000 years ago to about 45,000 years ago, when they went into a nosedive, said Miller... "The abundance of these spores is good evidence for a lot of large mammals on the southwestern Australian landscape up until about 45,000 years ago," he said. "Then, in a window of time lasting just a few thousand years, the megafauna population collapsed."

The Australian collection of megafauna some 50,000 years ago included 1,000-pound kangaroos, 2-ton wombats, 25-foot-long lizards, 400-pound flightless birds, 300-pound marsupial lions and Volkswagen-sized tortoises. More than 85 percent of Australia's mammals, birds and reptiles weighing over 100 pounds went extinct shortly after the arrival of the first humans, said Miller... "There is no evidence of significant climate change during the time of the megafauna extinction."
The article adds that last year Miller also identified the first direct evidence that humans preyed on Australian megafauna -- burned eggshells from a 400-pound bird.

Comments

Ah, the noble savage

[johannesg]

Serene, peaceful, in tune with nature, never takes more than he gives... And wipes out numerous complete (and unique) species.

Considering that Europeans still have to suffer demands for reparation for such things as slavery, colonisation, and the crusades, one cannot help but wonder if a demand for compensation for the irreparable damage to the ecosystem made by the aboriginals is also possible.

This shouldn't surprise anyone

[quonset]

We can look to our recent history and see the same extinction process created by man. The passenger pigeon, Tasmanian tiger, the Dodo, Great auk, Quaggas, Carolina parakeet and so on. Even today there are several species who are literally on the brink of going extinct, including the northern white rhino of which the last known male of its species is under 24 hour guard to protect it from poachers. Had it not been for Teddy Roosevelt, the American bison would most likely also be extinct, slaughtered by the literal tens of thousands as short as 130 years ago.

Man-made extinction also occurs in human populations. How many different Native American tribes were exterminated either because of Europeans or their Native American allies? How about those of Central and South America or those in the Far East?

We can see the same extinction process in places like Borneo where the habitat of orangutans is being wiped out due to illegal farming or clear cutting for palm oil trees, and similar processes under way in Madagascar where many animals exist in no other place on the planet, such as the ring-tailed lemur of which only an estimated 2,500 still survive.

Anyone who says man doesn't and can't have an effect on the environment is simply blind to reality.

Re: Not so innocent after all

[Layzej]

Yet, you got lied to and believed that climate change wiped out the Australian megafauna.

Lied to? By whom? Seems like Human impact has been the favoured explanation since before the turn of the century: Pleistocene Extinction of Genyornis newtoni: Human Impact on Australian Megafauna. Largely on account of the fact that climate change was modest over the period of extinction: "More than 700 dates on Genyornis eggshells from three different climate regions document the continuous presence of Genyornis from more than 100,000 years ago until their sudden disappearance 50,000 years ago, about the same time that humans arrived in Australia. Simultaneous extinction of Genyornis at all sites during an interval of modest climate change implies that human impact, not climate, was responsible."

Most people were probably not aware of this one way or another before reading this Slashdot post. Those that looked it up on Wikipedia would have found that Humans are thought to be the cause: "Analysis of oxygen and carbon isotopes from teeth of megafauna indicate the regional climates at the time of extinction were similar to arid regional climates of today and that the megafauna were well adapted to arid climates.[5] The dates derived have been interpreted as suggesting that the main mechanism for extinction was human burning of a landscape that was then much less fire-adapted; oxygen and carbon isotopes of teeth indicate sudden, drastic, non-climate-related changes in vegetation and in the diet of surviving marsupial species. However, early Australian Aborigines appear to have rapidly eliminated the megafauna of Tasmania about 41,000 years ago (following formation of a land bridge to Australia about 43,000 years ago as ice age sea levels declined) without using fire to modify the environment there,[7][8][9] implying that at least in this case hunting was the most important factor. It has also been suggested that the vegetational changes that occurred on the mainland were a consequence, rather than a cause, of the elimination of the megafauna.