Parrot DNA shows animal trade networks existed hundreds of years ago

Analysis of the genetic material shows colorful Amazonian parrots were transported alive across the Andes to coastal Peru centuries before the Inca Empire flourished, say scientists.

The trade network spanned hundreds of miles through rainforests, highlands and deserts, according to the study published in the journal Nature Communications.

An international research team analyzed parrot feathers that were discovered at Pachacamac in Peru - one of the major religious centers for the Andean civilization – far outside the birds’ native rainforest range.

Experts say parrots were prized for their vibrant feathers, which held deep cultural value in pre-Hispanic societies and were often used in ritual and high-status burial ceremonies.

Study lead author Dr. George Olah, from The Australian National University (ANU), explained that sequencing of the ancient parrot DNA uncovered a "thriving" network of trade and animal transportation that connected Amazonian forests with arid communities across the Andes.

He said: “Through combining ancient DNA sequencing, isotope chemistry and computational landscape modeling, we have been able to trace how and where these birds were moved across the landscape.

“Our ancient habitat modelling confirmed that the western side of the Andes was just as inhospitable to these species 1,000 years ago as it is today.

"These parrots are strictly rainforest dwellers with a natural home range of around 150 kilometers.

“The fact that they ended up more than 500 kilometers away, on the other side of South America's highest mountain range, proves human intervention.

"They do not naturally fly over the Andes.”

The research marks one of the first successful ancient DNA studies of fragile archaeological feathers, opening new avenues for tracking how organic materials moved through ancient trade networks worldwide.

The research team’s findings show that several species of Amazonian macaw parrots – native to the lowland rainforest just east of the Andes – were captured in the wild, carried high over mountain passes and kept alive on the coast long enough to grow fresh feathers in their new environment.

Genomic analysis identified four Amazonian species in the burial feather assemblage – the Scarlet Macaw, Blue-and-yellow Macaw, Red-and-green Macaw and Mealy Amazon – all native to rainforest habitat hundreds of kilometres from the Pacific coast.

The researcher say transport likely took weeks or even months, as travellers navigated rugged mountain passes and steep plateaus.

Dr. Olah said: “We can now demonstrate with genetic and isotopic evidence that these parrots weren’t just traded as feathers – they were transported alive, across dramatic terrain, into coastal ritual contexts."

By analyzing the chemical signatures contained in the feathers, the research team discovered that the birds’ diets shifted to C4 plants - such as maize - and marine protein, showing they were kept alive after crossing the Andes.

Dr. Olah said: “Our analysis reveals the parrots were fed the same nitrogen-enriched diet consumed by their captors – a clear sign of prolonged care after their removal from the rainforest.”

Landscape modeling further identified likely trans-Andean corridors and river routes used to transport the birds, revealing sophisticated overland and river exchange networks.

Dr. Olah added: “This discovery challenges long-held assumptions that pre-Inca societies were isolated or fragmented.

“Instead, we see evidence of organized exchange, ecological knowledge and logistical planning that connected vastly different environments long before imperial roads formalized these connections.”