Lab News

Ancient Turkeys Were Natural Recyclers

by Robin Lyle, Volunteer Researcher
November 20, 2006

A thousand years ago, domesticated turkeys at Albert Porter Pueblo scratched on the ground for corn, seeds, berries, nuts, and insects. Because they lacked teeth, it was essential for them to pick up small, naturally occurring rocks to help them grind foraged foods in their gizzards. But these objects weren’t the only things that appealed to them; it seems they also had an eye for all things colorful, shiny, and unique—including projectile points!

In a recent study of gizzard stones from Albert Porter Pueblo, we've found that these highly adaptive birds recycled many cultural materials in addition to naturally occurring stones. The accompanying photograph shows stone and pottery artifacts that were ingested by the Albert Porter turkeys and later retrieved as gizzard stones by Crow Canyon archaeologists.

Stone and pottery artifacts recycled as gizzard stones, Albert Porter Pueblo. Note the two projectile points (top). Photo by Robin Lyle.

Pieces of sandstone from broken masonry were turned into turkey gizzard stones, but they proved soft and wore out easily. Middens (areas where refuse was discarded) and structure floors were rich with broken pottery that turkeys recycled into gizzard stones. Colorful pebbles, liberated from conglomerate sandstone by tool makers, were also in the turkey's eclectic gizzard. This coarse sandstone was favored by villagers for grinding tools, but as pieces broke off, the turkey recyclers were there, picking them up.

Flakes of chert, mudstone, and quartzite make up the largest percentage of gizzard stones recovered from Albert Porter Pueblo. The ancient turkeys clearly had free access to work areas where stone tools were manufactured and discarded. Turkeys are highly visual foragers and would have been attracted to these colorful objects. As gizzard stones, these flakes are broken and worn smooth, but are still recognizable as the by-products of tool manufacture.

Interestingly, two gizzard stones from Albert Porter Pueblo were projectile points. One is a tiny, deeply notched chalcedony point, distinctly shaped by a flintknapper. Unfortunately, some enterprising turkey snatched it up while no one was watching.

But, you may ask, shouldn’t we classify these artifacts as projectile points, flakes, ground stone, or pottery? The staff at Crow Canyon must determine the last use to which an artifact was put. In the case of these small objects, the turkey recyclers have the final claim. They’re all gizzard stones!