Parrot feathers found at a thousand-year-old burial tomb in Peru provide new evidence for an expansive live bird trade network across the Andes Mountains that pre-dates the Inca Empire, a new study suggests.
The study, published earlier this month in Nature Communications, used parrot DNA, atomic isotope analysis, and spatial modeling to reconstruct the journey of the feathers from the Amazon Rainforest to the arid coastal desert of modern-day Peru.
Researchers say the study is a testament to the surprising complexity and interconnectedness of ancient civilizations—and also to the importance of cross-disciplinary research.
The feathers were found at Pachacamac, a religious center of the ancient Ychsma people in Peru and a major archaeological site of study. That’s where George Olah, a conservation biologist who happened to be studying macaw population genetics in the Amazon, first saw them.
“ I immediately recognized, those are my study species feathers,” Olah said. “I’ve been collecting them for months. I was just really intrigued that they’d find them in a tomb like that in such a different environment.”
Olah reached out to Izumi Shimada, one of the lead archaeologists on the site, to ask about the feathers, and the research began. The first step was to determine if these were truly parrot feathers. The preservation of DNA over thousands of years is a tricky business that depends on a lot of factors, like climate and location. But the arid coast of Peru offers great protection.
“ In a dry coastal environment, you get really good preservation,” said Aleksa Alaica, a multispecies archaeologist who peer-reviewed the study. “It very much varies by context, but the stars aligned in this particular type of study, where they had both the macroscopic and chemical preservation.”
Using DNA evidence, the researchers identified feathers from four species of Amazonian parrots. They also found high genetic diversity in the actual nucleotide mix of the feathers, which is indicative of a wild population of birds. In places like the southwestern United States, for example, researchers have found feathers from parrots bred in captivity that have very low nucleotide diversity due to inbreeding.
Balazs Tisza
So, the parrots were wild. But their natural habitat is not the dry desert climate of Peru’s western coast. How could the feathers have gotten there? They must have been transported from the Amazon, either on live birds or having been collected from the ground.
“Our ancient habitat modelling confirmed that the western side of the Andes was just as inhospitable to these species one thousand years ago as it is today,” said Olah. “These parrots are strictly rainforest dwellers with a natural home range of around 150 kilometres. The fact that they ended up more than 500 kilometres away, on the other side of South America’s highest mountain range, proves human intervention. They do not naturally fly over the Andes.”
To test this, the researchers checked the feathers’ isotopic signatures, which revealed their diets. Typical wild parrots have a “C3” signature, based on the isotope of carbon in the plants they eat. But these feathers had a “C4” signature, which points to foods like maize – common on the coast, but not in the rainforest. That meant that the birds had to have been brought across the Andes alive, and kept for about a year at least.
“Feathers molt usually once a year,” Olah said. “The feather is more like a snapshot of diet when the feather was actually growing. If you just capture a bird in the Amazon, the feather would still have the same isotope signature as in the rainforest. So we know that when these feathers were growing, the birds were in the coastal region.”
The Andes, however, are not hospitable. Travelers would have had to endure difficult high-altitude climbs while carrying large, presumably squawking parrots—and the harsh climate would not have been suitable for the parrots themselves over the long journey. In order to cross the mountains, the researchers suggest, the transporters likely took a route that veered north.
“ The northern portion of the mountain range is considerably lower,” Shimada said. “And furthermore, it is not incredibly cold or rugged.”
This northern route also has archaeological evidence to support it, because it coincides with the Chimú civilization, an expansive polity with heavy political and cultural influence.
George Olah
“These ties have deep historical roots,” the researchers state in the paper. The Chimú were “known to have had outposts and trade relationships with the Chachapoyas people of the upper Amazonian slopes, a region inhabited by the identified parrots and whose people were known for their bird-capturing skills. This suggests a sophisticated, multi-stage network: birds sourced by the Chachapoyas could have been traded to…Chimú (where the captive birds might have been reared at a larger scale) and then transported south to Pachacamac via established coastal routes.”
The genetic and isotopic findings of the study were initially surprising to the researchers, but the subsequent proposal of a trade network was not.
“This study is in line with more recent excavations and airborne imaging studies in the Amazon that are showing incredibly sophisticated villages, towns, and even cities united to each other and across to the Andes through vast networks of roads,” Beth Scaffidi, a biological anthropologist at University of California, Merced, told Refractor. “Studies like this one continue to peel back the veil and demonstrate a complex continuum of Andean-Amazonian relationships going back hundreds, if not thousands, of years before the Inca.”
And the fact that these complex journeys were undertaken for something as simple as parrot feathers supports the idea that we as humans have always had tastes that run toward the rare.
“ To this day, I think the population the world over have a certain sense about something exotic,” Shimada said. “We tend to put value on something exotic, wouldn’t you think so? And I believe that’s the key. The macaw feathers are incredibly vivid. They really wake your senses. But beyond that, you have to realize these are feathers from birds that live so far away. Most of us only heard about Amazonia. We have never been there. It’s really an exotic area, and colorful birds living in exotic land – all that adds up to create fascination. I believe that’s really what underlies the longstanding cultural interest in acquiring these birds’ feathers.”
Source: Australian National University
