A seven-feet-tall bird known as Genyornis newtoni dwelled in the Australian continent some 50,000 years ago. The researchers are claiming to have found strong evidence that human activities were responsible for the extinction of this bird that weighed around 500 pounds. Researchers are suggesting that humans harvested the eggs of this flightless bird. The study reveals that as humans ate the cantaloupe-sized eggs, it slowly deteriorated the reproduction ability of the birds and, thus, was unable to sustain their population.

Pieces of eggshells found at over 200 locations across Australia were studied by the researchers, with several of them recovered within small clusters of 10-feet diameter. This displays a scenario where humans would have disposed of eggshells in an around the fries that might have been created for cooking the eggs. Only one side of the eggshells’ gradients was burnt and had amino acid decomposition, which would have been not possible had the eggs been destroyed by wildfires.

“We instead argue that the conditions are consistent with early humans harvesting Genyornis eggs, cooking them over fires, and then randomly discarding the eggshell fragments in and around their cooking fires”, said Gifford Miller, the lead author and a professor at University of Colorado at Boulder.

Miller added that these are the first secure evidence that human preying resulted in the extinction of the megafauna in Australia. The eggshells are likely to be 54,000 to 44,000 years old, which falls in the time period of the humans’ arrival in Australia.

Changes in climate and intrusion of humans have been considered as the reasons for the extinction of Australian megafauna. However, the giant birds survived more drastic weather changes in the earlier time periods compared to those that occurred when they went extinct. Thus, human harvesting can be considered as the reason for their extinction.