Ancient humans’ taste for the eggs of a giant bird may have caused the species to go extinct, according to scientists who looked at burnt fragments of eggshells to find the connection between the bird’s extinction and humans.
In the new study – published online Friday (Jan. 19) in the science journal Nature Communications – a team of scientists from Australia and the United States, observed the burn patterns on the eggshells of the 500-pound bird called Genyornis newtoni.
Genyornis newtoni was about seven feet (2.1 metres) tall and weighed approximately five hundred pounds (about 226 kilograms) – which means that its eggs were probably 3.5 pounds (1.58 kg) heavy, and likely the size of a cantaloupe. The giant birds, as well as other massive animals, are a group known as megafauna (made of large or giant animals).
Despite the impressive size of some ancient animals – like the wombat that was the size of a car and the 1,000-pound (453 kg) kangaroo – they were no match for humans, since roughly 85 percent of these animals went extinct because of human activity.
Gifford Miller, a geology professor at University of Colorado, Boulder, said that the new study provides the first evidence that ancient humans hunted Australian megafauna.
According to Professor Miller, even though there was proof that most Australian megafauna still lived on the continent when people arrived on the scene, the lack of evidence with regard to human predation on massive animals in Australia led scientists to believe that no human-megafauna interaction ever existed.
It is still unclear when humans first arrived in Australia. However, scientists do known that the earliest people landed on the northern coast, and that they had scattered across the continent by 47,000 years ago.
Scientists used a technique called optically stimulated luminescence dating to study the eggshell fragments from the nesting sited of Genyornis newtoni. The technique determines age by examining quartz grains in the eggshells to find out when they were last exposed to sunlight, the scientists explained. Based on the results, the eggshells are between 44,000 and 54,000 years old.
The Genyornis newtoni eggshells form 200 sites (of the 2,000 sites that were sampled) were burned and blackened, the scientist found. They looked at the amino acid decomposition of the eggshells, in order to rule out the possibility of a wildfire.
The eggshells were not burned uniformly, but rather more burnt at one end than the other – which indicated cooking fires. They were also burned at temperatures of 1,000 degrees Fahrenheit (about 537 degrees Celsius), a lot hotter than those of bush fires – again indicating human involvement.
Image Source: colorado.edu