Intraspecific and environmental variation mediate seed finding effectiveness among scatter‐hoarding small mammals

About half of all plant species rely on animals such as scatter-hoarding small mammals for seed dispersal. These plants include many keystone species for which small mammals are key primary and secondary dispersal agents as well as seed predators. To predict the regeneration and movement of such plant species, we must understand small mammal seed finding effectiveness, or how many seeds they find and how quickly they find them. The ability of small mammals to find seeds is a critical first step of the seed dispersal or predation process, upon which all other steps depend, but it has received relatively little attention. With a field experiment, we aimed to fill this gap, uncovering environmental, demographic, and intraspecific predictors of seed finding effectiveness. We assayed the behavior of 1296 southern red-backed voles (Myodes gapperi) and 1053 deer mice (Peromyscus maniculatus) to identify and mark individuals with different personalities. Afterward, we established experimental seed stations with white pine (Pinus strobus) seeds and red oak (Quercus rubra) acorns scattered on the forest floor. We recorded the foraging behavior of 23 voles and 18 mice with known personality and assessed the effects of seed availability, environmental factors, small mammal density, and personality on their proportion of found seeds, seed finding rates, and probability of dispersing found seeds. More timid and docile voles found fewer white pine seeds and found them slower. Voles found more red oak acorns and found them more quickly when small mammal density was higher, and individual seed finding rates increased with white pine seed availability. At the community level, forest treatment and small mammal species richness influenced the number of found and removed seeds. These results contribute to identifying the factors that influence seed finding effectiveness, enhancing our understanding of this pivotal first step of seed predation and dispersal. We highlight the effect of personality on the quantity of found seeds and underscore the importance of considering behavioral diversity when predicting seed dispersal and predation rates.