Cassowaries may have been domesticated before chickens by brave (or foolish) humans

Long before chicken domestication, humans seem to have bred a different species of bird, capable of tearing a person apart with a single kick. Cassowaries make it easy to believe the status of birds as surviving dinosaurs, but according to a new study, these are the beasts humans have chosen to keep into adulthood. As strange as this decision may seem, it could explain the survival of the cassowary and the plight of the rainforests of New Guinea.

Eggshells deposited at Yuku and Kiowa in the New Guinea highlands appear to have been disproportionately harvested just days before they hatched. In the Proceedings of the National Academy of Sciences, the team that discovered this model explains it (almost in time for World Cassowary Day) as the result of people’s goal of raising newborns, not to cook the eggs.

The heaviest birds to have inhabited Earth in recent times – the New Zealand Moa and the Madagascan elephant bird – both quickly became extinct soon after humans arrived on their home islands. One way or another, however, three cassowary species have survived in New Guinea and Australia, cohabiting with humans for tens of thousands of years.

It is simply possible that the survival of cassowaries is the result of humans choosing to raise the young to adulthood as the best way to obtain their meat, rather than hunting wild birds on their own. If so, this has proven to be a very beneficial choice for the health of the tropical rainforests in which cassowaries live, allowing them to continue their vital role as seed sowers.

The shape and color of cassowary eggs change as they approach hatching, and the embryos absorb calcium from the shells. Dr. Kristina Douglass of Penn State University and her coauthors used this fact to study the developmental stages of seashells deposited at the two sites 18,000 years ago.

They also noted that while some shellfish showed signs of cooking; “There are enough samples of late-stage eggshells that don’t show scorching that we can tell they’re hatching and not eating them,” Douglass said in a statement.

Cassowaries live on fruit rather than meat, but their deadly claws still make them a major threat to anything they don’t like, including humans. Douglass suspects the dwarf cassowary variety Casuarius Bennetti were the ones that were bred, rather than the two larger species. Nonetheless, she noted; “It’s not a small fowl, it’s a huge, mean, flightless bird that can gut you.”

There are unconfirmed signs of humans forming a symbiosis with rock pigeons in Gibraltar 67,000 years ago, but that aside, the work presented here represents the oldest evidence of bird breeding in the human history. “This behavior that we are seeing happens thousands of years before chicken domestication,” said Douglass.

Cassowary nests are rare and difficult to find. In addition, the father keeps them and incubates them until they hatch. It would have taken considerable skill to identify the right time to harvest the eggs, and killing the male to reach them would have been risky. Nevertheless, New Guineans continue to breed cassowaries today, taking advantage of the fact that they easily imprint on humans if you are the first to feed them after hatching.