Turkey bones may help trace fate of ancient cliff dwellers

DENVER -- Researchers said they have found a new clue into the mysterious exodus of ancient cliff-dwelling people from the Mesa Verde area of Colorado more than 700 years ago: DNA from the bones of domesticated turkeys.

The DNA shows the Mesa Verde people raised turkeys that had telltale similarities to turkeys kept by ancient people in the Rio Grande Valley of northern New Mexico -- and those birds became more common in New Mexico about the same time the Mesa Verde people were leaving their cliff dwellings, according to a paper published last month in the journal PLoS One.

That supports the hypothesis that when the cliff dwellers left the Mesa Verde region in the late 1200s, many migrated to northern New Mexico's Rio Grande Valley, about 170 miles to the southeast, and the Pueblo Indians who live there today are their descendants, the archaeologists wrote.

The cliff dwellers would have taken some turkeys with them, accounting for the increase in numbers in New Mexico, the authors said.

Researchers long have debated what became of the people sometimes called Ancestral Puebloans, who lived in the elaborate Mesa Verde cliff dwellings and other communities across the Four Corners region, where the states of Arizona, Colorado, New Mexico and Utah meet.

Archaeologists believe the Ancestral Puebloans were a flourishing population of about 30,000 in 1200, but by 1280, they were gone, driven off by a devastating drought, social turbulence and warfare.

Because they left no written record, their paths are not known with certainty.

Many archaeologists and present-day Pueblo Indians believe the Ancestral Puebloans moved to villages across New Mexico and Arizona, and their descendants live there today.

Scott Ortman, a University of Colorado archaeologist and a co-author of the PLoS One paper, said the turkey DNA supports the explanation many migrated to an area along the Rio Grande north of present-day Santa Fe, New Mexico.

"The patterns that we found are consistent with several other studies and several other lines of evidence," he said in an interview.

Jim Allison, an archaeologist at Brigham Young University who was not involved in the paper, agreed the findings mesh with other evidence of a southeastward migration.

But a weakness of the study is the number of DNA samples used, he said.

Researchers examined DNA from nearly 270 sets of turkey remains -- some from before 1280 and some from after that date.

But only 11 sets of remains came from the Rio Grande before 1280.

"It would have been really nice to have 10 times as many," Allison said, but they were not available.

Ortman acknowledged the turkey DNA alone is not conclusive evidence of migration to the Rio Grande Valley.

The New Mexico turkeys could have come from someplace other than the Mesa Verde region, or turkey-herding communities already could have sprung up in New Mexico before the Ancestral Puebloans left their Mesa Verde communities, he said.