Plant Diversity Affects Rodents’ Selection of Different-Sized Seeds

Environmental changes may affect animal hoarding behavior through changes to plant diversity. Food hoarding behavior in small mammals can affect the seed dispersal process and thus the regeneration of the plant population. However, little is known about how small mammals select seeds of different sizes under different forest types. Here, we tracked the fates of 3360 seeds in the field. We used a generalized linear mixed model to analyze the effects of small mammals on three fates (predation in situ, predation after dispersal, hoarding after dispersal) and two dispersal distances (predation distance after dispersal and hoarding distance after dispersal) of different seeds by size and forest type. The results showed that small mammals consume smaller seeds in situ and cache larger seeds after dispersal. The predation distance after dispersal and hoarding distance after dispersal of the large seeds were significantly higher than those of small seeds. Forest types with dense vegetation conditions exhibited lower hoarding rates after dispersal, while those with poor vegetation conditions had increased predation and hoarding distances after dispersal. Our results suggest that larger seeds are dispersed to further distances, potentially enhancing plant population regeneration. However, seeds are more often scatter-hoarded and dispersed over longer distances in forests with poor vegetation conditions, which may also benefit plant population regeneration. These results provide insights into how seed size and forest type influence seed predation and dispersal by small mammals.