Archaeologists are rewriting the history of the Pacific with new evidence that Polynesian voyagers visited South America at least once, and perhaps repeatedly, long before the first Europeans arrived on the scene.

The new clue involves chickens: Evidence shows that chickens that were genetically nearly identical to those in Hawai'i and other Pacific islands were on the coast of Chile at least a century before the first Spanish and Portuguese visit to the New World.

Added to previous research showing that two species of plants from the Americas are widespread in Polynesia, it supports the case for Polynesia-America contact.

"It is a great testament to the skill of Polynesian navigators," said University of Hawai'i archaeologist Terry Hunt, a co-author of a study that was to be published in yesterday's proceedings of the National Academy of Sciences. Its lead author is New Zealand anthropologist Alice Storey. Hawai'i archaeologists Hunt and Steve Athens are among the co-authors.

"This is huge," said Polynesian Voyaging Society president and traditional navigator Nainoa Thompson. He said the news is a real boost for Hawaiians and the nations of Polynesia — whose boundaries have been described as a triangle with its points at Hawai'i, New Zealand and Easter Island or Rapa Nui.

"When I was in school, the Polynesian Triangle didn't exist. We weren't taught about it," Thompson said.

"Now we're learning that perhaps the triangle is too small. There is evidence of Polynesian presence on the east coast of Australia, a connection with Madagascar, and now South America. Their exploration may actually have been global."

Some kind of contact between Polynesia and South America has long been assumed, because of the presence throughout Polynesia of two American plants — the kumara or sweet potato, known as 'uala in Hawaii; and the bottle gourd, ipu in Hawaiian.

Still, they only prove an east-to-west movement, from South America into the Pacific.

"But until now, there has never been conclusive evidence of a Polynesian 'thing' in the Americas," said study co-author Elizabeth Matisoo-Smith, of the University of Auckland, New Zealand, in an e-mail.

A CRUCIAL BONE

The "thing" ended up being a chicken bone at an archaeological site called El Arenal-1 on Chile's Arauco Peninsula, the earliest evidence yet found of chickens in the Americas.

"In my view, the only plausible explanation for both of these transfers is seafaring Polynesians voyaging from eastern Polynesia to South America and returning," said University of California-Berkeley archaeologist Patrick Kirch.

"Given what we have learned over the past few decades with Hokule'a and other experimental voyages, such feats were well within Polynesian voyaging capabilities," added Kirch, who was not involved in the study but had read the report.

Radiocarbon dating puts the chickens at the site within the 1300s — long before Columbus' 1492 arrival in the Caribbean. And the chickens could have been there earlier, since there is no way to tell whether the Arauco site contains the continent's oldest chicken remains.

The team also conducted DNA studies and found that the Arauco chicken was closely related to chicken remains from archaeological sites in much of Polynesia dated to the same period, including samples found at Kualoa on O'ahu, Anakena on Rapa Nui and in Tonga and Samoa.

It is possible that there was just a single contact — a double-hulled voyaging canoe that landed on mainland South America, traded chickens for sweet potatoes, and departed, never to return. If so, that site would not have been on the Arauco Peninsula.

Matisoo-Smith said it is too cold there, at 37 degrees south latitude, to grow sweet potato.

"We suggest that it was probably one of several contact events — and that Polynesians were the ones doing the voyaging — potentially dropping off the chicken and picking up the sweet potato," she said.

Hunt said that with the known multiple transfers — chickens showing up in the south and sweet potatoes coming from the northern part of South America — repeated voyages seem likely.

Matisoo-Smith said she hopes to develop further evidence of the role of Polynesians in early South America with tests looking for more early chicken remains as well as evidence of Pacific rats in South American archaeological sites.

"I am planning on heading over to Chile in the next year to look through museum collections, not only for chicken but also for any evidence of the Pacific rat (Rattus exulans)," she said. "We have been tracking rat DNA across the Pacific for nearly 10 years now — and pretty much anywhere that Polynesians went (or Polynesian ancestors), the rat went with them — so we would expect to find some exulans bones in South American sites, too."

Sam Gon III, senior scientist and cultural advisor to The Nature Conservancy of Hawai'i, said the study "opens the door for evidence of other forms of cultural exchange" between Polynesia and South America. Polynesians are now believed to have sailed into the eastern Pacific in two major waves, starting about 1,200 years ago, Hunt said.

Reach Jan TenBruggencate at jant@honoluluadvertiser.com.