In Mexico, nature reserves vary greatly in the size of the property, administration, financial budget and measures to protect against land use change and illegal hunting. We compared two private and two public reserves and observed an influence between the ownership structure and the patterns of removal of large and small seeds from the forest floor by medium-sized mammals and rodents. We hypothesized that removal of all seeds, of large seeds only, and the removal of seeds by the medium-sized mammals would be higher in the private than in the public reserves as a consequence of better conserved populations in the private reserves. We also expected a direct effect of seed removal on seed germination. Medium-sized mammals removed more large-seeds in the private than in the public reserves, whereas removal of small seeds by rodents was lower in the private than in the public reserves, indicating an absence of larger-sized mammals in the latter. Seed germination was higher in control plots where seed removal was prevented by excluding all mammals. We conclude that patterns on seed removal by mammals in reserves can be strongly influenced by the type of ownership and hence the extent of their conservation.