In this study, I investigated the effects of seed size and habitat on post-dispersal predation of Quercus chrysolepis and Lithocarpus densiflora acorns in central coastal California. Tagged acorns were located at five distances across two forest-grassland ecotone sites. Although Q. chrysolepis acorns were nearly twice as large as those of L. densiflora, there was no significant difference in predation between the species or sites. There was, however, a significant difference in acorn predation between habitats, with both species having much higher rates of predation in the forest than in the grassland. While predation occurred across the forest-grassland ecotone, acorn burial only occurred in the forest. These results suggest that habitat had a stronger effect on post-dispersal predation than seed size.