Is partial acorn consumption a strategy to avoid depletion of caches during pilferage of acorns?

Cache pilferage by competing conspecifics is very common in hoarding behaviour in animals and members of rodent communities use a wide variety of strategies to minimize it. In this study, we investigated one of these strategies. We observed that some rodent species partially consume acorns leaving the embryo intact. We investigated whether this behavior in Mus spretus Lataste 1883 (Algerian mouse), was a strategy to avoid cache pilferage by competing conspecifics. Partially consumed acorn remains generated in underground stores could be seen by competing conspecifics as leftovers and rejected. They would not be consumed and therefore not stolen.
To test the veracity of our hypothesis, we designed three experiments in which we studied preference for intact acorns, acorns partially consumed by the rodent itself or remains produced by other rodent competing conspecifics. We wanted to know whether the leftovers of partially consumed acorns were rejected.
We verified that these remains are more highly valued than intact acorns and even the remains of the rodent’s own previous consumption, thus indicating that our hypothesis is untrue. They are not used as a strategy to avoid theft. However, preference for the remains of other rodents’ acorns could well form part of an anti-theft strategy. If they are being used as a decoy to attract the attention of thieves to prevent intact acorns from being consumed, the intact acorns would remain better preserved in the stores for a longer time. The remains were consumed before intact acorns. We verified that rodents prefer the remains of other rodents’ acorns to their own, and even to intact acorns. This behavior would form part of the strategy aimed at reducing the reserves of other rodents to avoid future competition by conspecifics.