Scarlet Macaws
Scarlet Macaws are highly prized in the Pueblo cultureSteve Parsons/PA Wire

The skeletal remains of scarlet macaws found at ancient Pueblo settlements suggest the emergence of political hierarchies among Native Americans occurred much earlier than first suspected.

The feathers of scarlet macaws are highly valued in the Pueblo culture and were often purchased from the Mesoamerican people in the mid-11th century.

It was thought that the Pueblo people did not bring these luxury items, along with other valued goods such as chocolate and turquoise, back to their settlements in the south west of the US until around 1040 AD – the beginning of the Chaco florescence period, an era of rapid architectural expansion and what was thought to be the commencement of political hierarchical systems among the Pueblo people.

However, after radiocarbon dating items including macaw skulls from the Chaco Canyon, scientists are beginning to see things differently. The largest of the Chaco Canyon's establishments was the Pueblo Bonito, which had 650 rooms, according to the findings published in the Proceedings of the National Academy of Sciences.

The remains of 30 macaws were found in this establishment, including 14 in one room that scientists believe was a sort of aviary judging by the guano present. It was thought that the birds were obtained during the Chaco florescence period, but advances in technology have helped the team pinpoint a more accurate date, around the late 800s to mid-900s – 150 years earlier than previously thought.

Adam Watson, a post-doctoral fellow in the American Museum of Natural History's Division of Anthropology and lead author on the paper, said his team believe that trading the South American parrots could have been the catalyst for the establishment of hierarchy within the society.

Watson said: "By directly dating the macaws, we have demonstrated the existence of long-distance networks throughout much of this settlement's history.

"Our findings suggest that rather than the acquisition of macaws being a side effect of the rise of Chacoan society, there was a causal relationship. The ability to access these trade networks and the ritual power associated with macaws and their feathers may have been important to forming these hierarchies in the first place."