Is Mus spretus a mutualistic species with oak species or does it parasitize previously established relationships with other rodents?

Abstract Relationships between oak species and rodents have been interpreted in terms of their performance within a range of relationships ranging from the antagonistic extreme called a predation relationship because rodents destroy acorns to the collaborative extreme in which the two species obtain benefits in a relationship called mutualism. In the Iberian Peninsula there are two species of rodents, Apodemus sylvaticusand Mus spretus. A. sylvaticus arrived first, in the Pliocene, and established mutualistic relationships with the oak species that existed there because it partially consumes acorns and initiates them from the basal part, which allows the embryo to be preserved. It brings to the relationship a higher energy expenditure when opening the acorns at the basal end, but in exchange it obtains a stable and persistent source of resources, although with temporal oscillations. Later came M. spretus, in the Holocene. As both species currently share habitat and food, the question we pose in this study is the following: How did M. spretus respond to the mutualistic relationship already maintained by A. sylvaticus and the oak species of the Iberian Peninsula? Did it adopt the same behavior as A. sylvaticus to contribute to the dissemination of acorns that will serve as food? Or, on the contrary, does it parasitize this relationship by behaving as a simple predator of the acorns that A. sylvaticus has contributed to establish and spread? The result we have obtained is that M. spretus has acquired the same acorn processing behavior as A. sylvaticus. Therefore, we can affirm that M. spretusis a species that maintains mutualistic relationships with the oak species settled in the Iberian Peninsula.