Instead, the higher lake levels could mean more surface water due to decreased evaporation rates during the Wisconsin. Packrats collect the native vegetation and secure it in their nests using their urine, which hardens into a substance known as amberrat . This method is very efficient in locations where pollen cores can t be extracted. Two supplementary techniques are used in conjunction with packrat middens. First, the material in the midden must be dated to place its construction in temporal context.
Radiocarbon dating is used most often.
Second, the pollen from packrat middens can also be extracted to verify the macrofossil assemblage found in the midden itself. All rights reserved. Last updated 19.Apr.2000.