Plant macrofossils methods and studies: rodent middens

Rodent middens are caches of objects including edible plants, insect and vertebrate remains, small pebbles, and feces, brought to the den site for a variety of reasons including food, curiosity and den protection; then they are cemented into black tarry masses by rodent urine. Once dried, the exterior of the midden hardens into a protective coating that can preserve a paleoecological record for thousands of years in dry rock shelters of arid regions. The study of plant macrofossil records derived from rodent middens is expanding our knowledge of the desert paleoecology by providing data on the nature and timing of vegetation responses to environmental change. This article focuses on the late Pleistocene and Holocene vegetation of the arid regions of North America, as reconstructed from plant macrofossils sampled from packrat middens.