As early as 18,000 years ago, humans in New Guinea may have collected cassowary eggs near maturity and then raised the birds to adulthood, according to an international team of scientists, who used eggshells to determine the developmental stage of the ancient embryos/chicks when the eggs cracked.
“This behavior that we are seeing is coming thousands of years before domestication of the chicken,” said Kristina Douglass, assistant professor of anthropology and African studies, Penn State. “And this is not some small fowl, it is a huge, ornery, flightless bird that can eviscerate you. Most likely the dwarf variety that weighs 20 kilos (44 pounds).”
The researchers report today (Sept. 27) in the Proceedings of the National Academy of Sciences that “the data presented here may represent the earliest indication of human management of the breeding of an avian taxon anywhere in the world, preceding the early domestication of chicken and geese by several millennia.”
Cassowaries are not chickens; in fact, they bear more resemblance to velociraptors than most domesticated birds. “However, cassowary chicks imprint readily to humans and are easy to maintain and raise up to adult size,” the researchers report. Imprinting occurs when a newly hatched bird decides that the first thing it sees is its mother. If that first glance happens to catch sight of a human, the bird will follow the human anywhere.
According to the researchers, cassowary chicks are still traded as a commodity in New Guinea.
Importance of eggshells
Eggshells are part of the assemblage of many archeological sites, but according to Douglass, archaeologists do not often study them. The researchers developed a new method to determine how old a chick embryo was when an egg was harvested. They reported this work in a recent issue of the Journal of Archaeological Science.