科学美国人60秒:Ancient Americans Bred Symbolically Important Scarlet Macaws

Abandoned pueblos are scattered throughout the southwestern U.S. And at many, archaeologists have uncovered a curious artifact: the skeletons of scarlet macaws. The birds' bright red feathers are known to have been an important status symbol, a signifier of prestige, for people throughout the American tropics and the southwest… both in the ancient world and today.

But macaws are a tropical bird, whose range never extended north of today's U.S.-Mexico border. So how did the pueblo people obtain the birds?

To examine the birds' origin, scientists sequenced mitochondrial DNA found within macaw bones from two sites in New Mexico: Chaco Canyon and the Mimbres region. Turns out, nearly three quarters of the birds had identical mitochondrial genome sequences—meaning the ancient birds came from the same maternal line. That suggests they were all the products of a breeding operation, perhaps in modern-day northern Mexico, rather than a random collection of wild-caught birds. 

"If it was just more random, you know, forgive the word, ‘plucking,’ random macaws from the environment, we would have expected to see a type of diversity that you'd see in the wild."

Richard George, a PhD candidate in anthropology at Penn State.

"When we took our results and compared them to macaws distributed throughout the historic and modern ranges, the results were more analogous to other species of animals that were being bred, like turkeys or dogs or pigs." 

The details are in the Proceedings of the National Academy of Sciences. [Richard J. George et al., Archaeogenomic evidence from the southwestern US points to a Pre-Hispanic scarlet macaw breeding colony]

The discovery adds an additional layer of complexity to our understanding of Southwestern and Mesoamerican cultures: they had the sophistication to breed and manage the distribution of these exotic birds. And it's an example, too, of how modern sequencing technology can unlock historical and cultural secrets, that sat waiting in these bones for more than 800 years.

—Christopher Intagliata