Stick-nest rat middens and a late-Holocene record of White Range, central Australia

Abstract

Stick-nest rat middens are preserved piles of macrofossils that record changes in plants and animals during the late Holocene at White Range. The builders, Lesser Stick-nest Rats (Leporillus apicalis), after at least 2500 years in the area, became extinct during the Modem radiocarbon period. The rats' collection of plant and animal material provides an ecological survey of the site during this period. The species composition of the vegetation has apparently responded to increased Aboriginal populations, fire incidence or rainfall in the last 2500 years. A dramatic increase in tree and shrub material between 2510 +40 BP and 835 +62 BP at the expense of herbs is possibly related to increasing moisture availability. The middens record a collapse of trees and shrubs by 606+136 BP then a strong recovery. Grasses have generally decreased in importance throughout the record. Bones of the Central Rock Rat (Zyzomys pedunculatus), which is currently restricted to the western MacDonnell Ranges, were found in middens dated at 433 +60 BP. Information about long-term changes in Australia's arid areas is accessible using the middens of stick-nest rats and provides a useful long-term perspective for environmental management.