The seed size/number trade‐off model explains the co‐existence of plants that produce different‐sized seeds by assuming an establishment fitness advantage for larger seeds via enhanced competition or environmental tolerance, and a colonization fitness advantage for smaller seeds. The model predicts a negative relationship between seed mass and plant abundance among co‐existing species in a community. Here, we evaluate the hypothesis that rodent granivory affects the slope of this relationship, causing it to become less negative when granivore pressure is reduced because rodents selectively harvest large seeds.