OLFACTORY DETECTION OF CACHES CONTAINING WILDLAND VERSUS CULTIVATED SEEDS BY GRANIVOROUS RODENTS

We conducted a study to examine the ability of granivorous rodents to detect caches made with wildland (native and nonnative) and cultivated seeds at 3 locations in western Nevada with different vegetation types and rodent community structures. We established artificial caches containing either 2 or 3 species of wildland seeds or cultivated seeds. Five seed species were tested it each site. Under dry conditions, rodents found caches containing cultivated seeds much more rapidly than caches containing wildland seeds. Wet conditions resulted in a similar order of delectability; however, all species of seeds were located much faster in wet conditions than under dry conditions. Natural selection has likely acted on the wildland seeds to reduce their olfactory signal and potentially reduce predation upon those seeds.