Aggression and coping. Differences in behavioural strategies between aggressive and non-aggressive male mice

In populations of wild house mice extremely high and low aggressive males are abundant, which is the result of diversifying natural selection. The aggressive mice are more succesful under stable conditions (like within a family group, called a deme), whereas non-aggressive males function better under changing conditions (i.e. migratory circumstances). These findings implicate that not only aggression, but also the absence of aggresion belongs to the functionally significant equipment with which animals interact with the social environment. A second implication is that aggressive and non-aggressive male mice may differ more fundamentally in their general interaction with the environment, regarding their different succes under different conditions. Therefore, the following questions are addressed in this thesis: 1) do aggressive and non-aggresive mice respond in alternative ways to various interactions, 2) do aggressive and non-aggressive male mice differ more generally in behavioural strategy in response to non-social situations and 3) can the supposed difference be interpreted in terms of different, but equivalent coping styles? ... Zie: Summary