Differences in food hoarding among six species of heteromyid rodents

Storing food is an important adaptation of heteromyid rodents to desert env ironments of southwestern North America. These rodents store seeds in burro ws (larder hoarding) and in small, widely scattered caches buried at shallo w depths in soil (scatter hoarding). Laboratory trials were done with five species from one site and two species from two other sites to test the hypo thesis that larger species would larder hoard relatively more seeds than sm aller species. Subjects were tested in arenas consisting of a sand-filled b ox for scatter hoarding and a nest box for larder hoarding. Chisel-toothed and Merriam's kangaroo rats (Dipodomys microps and D. merriami) from one si te larder hoarded more than sympatric dark kangaroo mice (Microdipodops meg acephalus) and long-tailed and little pocket mice (Chaetodipus formosus and Perognathus longimembris). Chisel-toothed kangaroo rats larder hoarded mor e than Merriam's kangaroo rats and little pocket mice larder hoarded more t han dark kangaroo mice. These results were consistent with reported informa tion on the relative aggressive behaviors of the species. For subjects from the other two sites, Ord's kangaroo rats (D. ordii) larder hoarded more th an the smaller Merriam's kangaroo rats. Pocket mice made larger scatter hoa rds than kangaroo rats and placed these scatter hoards closer to edges and corners of arenas than kangaroo rats. Differences among species in food-hoa rding behavior should be considered in future studies of the community ecol ogy of desert rodents.