For Clues on Climate, Seeing What Packrats Kept

Geoffrey Spaulding and Kenneth L. Cole lifted off from a high plateau in the Grand Canyon, their helicopter laden with so many packrat nests that it could barely climb.

“The chopper gave this sickly shudder as we made our way back across the chasm of the canyon,” Dr. Spaulding recalled. “Thank goodness for those Vietnam-vet pilots.”

To Dr. Spaulding, a geologist with the engineering company CH2M Hill, and Dr. Cole, an ecologist for the United States Geological Survey, the nests were precious cargo. Packrats, which look like brown squirrels with Dumbo ears, are skilled home builders, and their massive nests, known as middens, can last 10,000 to 20,000 years (though they are not usually inhabited the entire time).

from the NY Times