Role of partially consumed acorn remains in scatter hoards and their implication in oaks colonization process.

Abstract

Abstract In previous studies, authors have demonstrated the benefits of rodent participation in the colonization process carried out by oak species. We have observed that certain rodent species (Apodemus sylvaticus and Mus spretus) partially consume acorns, beginning at the basal part and preserving the embryo. Perea et al. (2011) and Yang and Yi (2012) found that during periods of abundance the remains produced after partial consumption are left on the surface without being transported to caches because they see as leftovers. The objective of this study is to know the role played by the remains of partially consumed acorns in the caches. To verify if these remains are seen as offal and are therefore rejected. To test this, we provided rodents with intact, partially eaten acorns to ascertain their preferences for own or foreign remains or the rejection of both. The results indicate that preferences are directed towards consuming first the remains produced by other rodents, then their own, leaving intact acorns for last. The reasons are based on questions of energy balance. Removing the shells from acorns is very costly in terms of energy, so it is preferable to use the shelled remains first, even if they must pass through a layer of fungi and molds to reach the cotyledons. The first remains to be consumed are those of others, because in case of scarcity it is convenient to conserve one's own resources.