09-28-2021 Cassowary chicken RESEARCH AND TECHNOLOGY POLICY ANDY MACK
MADRID, 27 (EUROPA PRESS)
Humans of New Guinea from the late Pleistocene, 18,000 years ago, could have collected cassowary eggs near maturity and then raised the birds to adulthood.
It is the result of the examination of eggshells obtained in archaeological sites to determine the stage of development of the embryos when the eggs were broken. It is published in the Proceedings of the National Academy of Sciences.
“This behavior that we are seeing is thousands of years before the domestication of the hen – related in a statement Kristina Douglass, associate professor of anthropology and African studies at the State University of Pennsylvania (Penn State), in the United States – And it is not a small bird, but a huge, intractable, flightless bird that can gut you. Most likely it is the dwarf variety that weighs 20 kilos. “
The researchers, from the United States, New Zealand, South Africa and the United Kingdom, report that “the data presented here may represent the first indication of human management of the breeding of an avian taxon anywhere in the world, predating by several millennia. the early domestication of chickens and geese “.
Cassowaries are not chickens, in fact they are more like velociraptors than most other domesticated birds. “However, cassowary chicks are easily attached to humans and are easy to keep and raise to adult size,” the researchers report. The bond occurs when a newborn bird decides that the first thing it sees is its mother. If that first glance matches that of a human, the bird will follow it anywhere.
According to the researchers, cassowary chicks continue to be traded in New Guinea.
Eggshells are part of many archaeological sites, but according to Douglass, they are rarely studied by archaeologists. The researchers developed a new method to determine the age of a chick embryo when an egg was collected, which they reported in a recent issue of the ‘Journal of Archaeological Science’.
“I’ve been working with archaeological eggshells for many years,” Douglass explains. “I discovered research on turkey eggshells that showed changes in eggshells throughout development that were an indication of age. that this would be a useful approach. “
The allocation of the age of the embryos / chicks depends on the three-dimensional characteristics of the interior of the shell. To develop the method necessary to determine the developmental age of eggs when shells break, the researchers used ostrich eggs from a study conducted to improve ostrich reproduction.
Researchers at South Africa’s Western Cape Government Oudtshoorn Research Farm collected three eggs each incubation day for 42 days for study and provided Douglass and his team with samples of 126 ostrich eggs.
They took four samples from each of these eggs for a total of 504 shell samples, each with a specific age. They created high-resolution 3D images of the shell samples. By inspecting the inside of these eggs, the researchers created a statistical assessment of the appearance of the eggs during the incubation stages. They then tested their model on modern ostrich and emu eggs of known age.
The interior of egg shells changes throughout development because developing chicks obtain calcium from the shell. The pits begin to appear in mid-development. “It depends on time, but it’s a bit more complicated,” explains Douglass. “We use a combination of 3D imaging, modeling, and morphological descriptions.”
They then turned to the shell collections inherited from two sites in New Guinea: Yuku and Kiowa. They applied their approach to more than 1,000 fragments of these eggs that are between 18,000 and 6,000 years old.
“What we found was that a large majority of the eggshells were collected in late stages,” reveals Douglass. “The eggshells appear very late; the pattern is not random. They were either eating baluts or hatching chicks.” . A balut is a nearly developed embryonic chick that is often boiled and eaten as street food in some parts of Asia.
The original archaeologists found no indication that the cassowaries were in a corral. The few cassowary bones found in the sites are only those of the fleshy parts – leg and thigh – suggesting that they were hunted birds, processed in nature and that only the meatiest parts were taken home.
“We also looked at the burning of the eggshells,” Douglass continues. “There are enough samples of late-stage eggshells that show no burns, so we can say they hatched and didn’t eat them.”
To successfully hatch and raise cassowary chicks, people would have to know where the nests were, know when the eggs were being laid, and remove them from the nest just before hatching. According to Douglass, in the late Pleistocene, humans collected these eggs on purpose, and this study suggests that people did not just collect the eggs to eat their contents.