Parrots’ colorful blue, green, and red feathers were the status symbol, “essential for communicating status, power, and cosmology,” as Olah and his colleagues put it. In the Andes highlands, the Wari—and later the Inca—imported bright-feathered rainforest birds in the millions over several centuries. On the coasts, the Moche and Nasca cultures did much the same.

Parrot feathers feature in headdresses and in tunics made from thousands of feathers sewn onto cotton cloth. The birds themselves show up in tombs and temples as mummified offerings, and they were sculpted and painted onto centuries’ worth of pottery.

The parrot feathers on a handful of funerary headdresses from one of the only unlooted, intact tombs left at Pachacamac recently indicated that the Ychsma were linked to a trade network that once connected huge swaths of two continents across hundreds of kilometers.

Based on parrots and their feathers alone, archaeologists knew there must have been connections that reached from the Amazon basin west to the coastal deserts of Chile and Peru and north to Mexico and the southwestern United States. But the details of that trade—including how live parrots ended up crossing one of the world’s most daunting mountain ranges—were unclear for the centuries before the rise of the Inca Empire and its imperial road networks.

Until recently, archaeologists and historians assumed that the period between the breakup of the Wari Empire and the rise of the Inca was mostly a time when smaller kingdoms and confederations, like Ychsma and its neighbors, squabbled with each other and had influence that didn’t reach much beyond their own region. But based on parrot feathers, these between-empires Andean cultures actually had complex, thriving, and very sophisticated trade relationships without needing to have a system imposed by a central imperial government.

Born in the rainforest, raised in the desert

The headdress feathers came from four parrot species: scarlet macaws, red-and-green macaws, blue-and-yellow macaws, and mealy amazons. (The last are cute little green dudes that really deserve a nicer name; “mealy” is apparently a reference to the dusty “powder down,” grains of keratin formed by the disintegrating tips of their down feathers.) All of them live in lowland tropical forests and palm swamps in the Amazon Basin; Peru’s coastal deserts are practically the opposite of their usual wet, lush habitat.