New evidence of pseudosexual behaviour and female aggression in mice: neutral cage interactions in Mus spicilegus and Mus spretus (Rodentia : Muridae)

Intrasexual dyadic interactions performed in a neutral cage were studied in two species of aboriginal house mice. Encounters in the mound-building mou se, Mus spicilegus, were highly agonistic. Females spent equally important proportion of time in agonistic behaviour as did males, in addition, males of this species regularly exhibited pseudosexual behaviour, involving exces sive sniffing and even mounting of their opponents. The above mentioned pec uliar features of the behavioural profile of Mus spicilegus are discussed. In contrast to Mus spicilegus, both sexes of the Algerian mouse, Mus spretu s, were fairly peaceful. However, as in most species of murids, male-male i nteractions were more agonistic than those female-female ones.