The giant 225-kg-bird that used to live in Australia (I mean, where else?) 50,000 years ago went extinct because of humans (who else, right?!), says new study published in Nature Communications.
Australia is notorious for its special collection of unique animals. It is little wonder that it once had an enormous bird weighing around 225 kg with a height of nearly 2 metres walking on its ground. The bird’s egg was comparable in size to a cantaloupe, weighing around 1.5 kg.The bird is known as Genyornis newtoni. And, no, worry not, it could not fly.
The earth allegedly witnessed the existence of other fantastic beasts during the time of the G. newtoni such as the 450-kg kangaroo, a 2-tonne wombat, a nearly 8-metre-long lizard, a 135-kg marsupial lion, and a giant tortoise the size of a modern car. The extinction of these giant animals in Australia has been difficult to prove relative to human predation; evidence does exist of their presence back when humans colonised Australia, but understanding whether humans predated on them has been challenging. According to the authors of this study, though, their findings constitute the first evidence of humans directly preying on the Australian giant bird.
The bird is claimed to have lived in several areas of the country before the settlement of humans. When the latter did establish themselves in Australia, they might have played a role in the extinction of the species, says Professor Gifford Miller, one the authors of the paper. The evidence gathered by the team of researchers indicates the apparent involvement of humans: burn patterns on fragments of eggshells of the birds suggest that humans would cook the eggs which led to a decrease in the bird population as their reproductive success was subject to interference.
The researchers have analysed both burnt and unburnt eggshells. They discovered the former at over 200 sites across Australia while the latter were obtained from more than 2,000 places across the continent in sand dunes where the birds might have once built their nests. Dating techniques put their minimum age at 45,000 years old. The partial blackening of some of the burnt eggshell fragments suggests that the pieces were subjected to a vast range of temperatures. Now, how did the eggs get burnt? Humans. The researchers think they might have been burned in transient human fires (as opposed to wildfires) used for cooking purposes. Also, some of the burnt eggshell pieces were found in tightly-bound groups which makes the cooking theory more believable.
Further analysis seems to support this hypothesis. The eggs have possibly been burnt by a localised heat source. This was concluded from the ‘gradient’ of the decomposition of amino acids which make up the shell. Moreover, the heat gradient differences of individual fragments coming the same cluster amounted to around 500 degrees Celcius, making the possibility of natural wildfires seem unlikely.
The authors think that the conditions they found are consistent with the theory that humans would collect and cook the eggs over fires, thereby ultimately leading to the extinction of the giant bird.