In addition to consuming seeds, many granivorous small mammals also cache seeds in shallowly buried scatterhoards, and seeds of many plant species are known to germinate and establish aggregated clusters of seedlings from these caches. Scatterhoards made by desert heteromyid rodents provide the primary source of seedling recruitment for Indian ricegrass (Achnatherum hymenoides), a perennial bunchgrass species occurring widely across the southwestern deserts of
Individual seedlings within clumps at Flanigan had significantly higher survival rates than seedlings growing singly in 2 of 4 plots, but single seedlings had higher survival than seedlings in clumps on another plot. There was an overall inverse effect of clump size on seedling survival. However, one or more seedlings survived its first year in nearly all clumps, and individual seedlings within intermediately-sized clumps of 41-60 seedlings had significantly greater survival (56%) than those in smaller or larger clusters (all < 45%), suggesting that clumping of seedlings may benefit fitness. Although individual seedlings within caches were not counted at the Hot Springs Mountains study site, whole caches had significantly higher survival curve functions than single seedlings. Overall, results suggest that benefits accruing to Indian ricegrass due to seed-caching desert rodents often extend past the seedling establishment phase and into the longer-term survival of the plant.