PREDATORY BEHAVIOR IN FEMALES OF 2 STRAINS OF MICE SELECTIVELY BRED FOR ISOLATION-INDUCED INTERMALE AGGRESSION

The study sought to determine whether females of two strains of mice s electively bred for high (Turku Aggressive, TA) and low (Turku Non-Agg ressive, TNA) levels of isolation-induced intermale aggression display differences in predatory behaviour. Additional subjects used in the s tudy were females of the parental strain (Normal, N). Another aim of t he present research was to investigate whether predatory aggression is associated with the postpartum period in the TA and TNA females. Test ing consisted of dropping a live cricket into the home cage of the exp erimental females. The results showed that the predatory behaviour of individually housed TA and TNA females did not differ significantly. T he only difference found between the two groups of females was in digg ing behaviour, the TA females showing more of this activity element on the first day of testing. Experience was found to affect the behaviou r of the mice, attacking and consuming increased over trials whereas s niffing and the latency to attack decreased. In another experiment, TA and TNA females were tested for predatory aggression on the third day postpartum The TA and TNA females were found to differ in all other o bserved behaviour variables but sniffing. The TA females spent more ti me chasing, tail-rattling, attacking, and consuming, as well as showin g shorter latencies to the first attack. The TNA females spent more ti me digging, grooming, and nursing. The results suggest that the mechan isms determining the dispositions for predatory and maternal aggressio n in females and isolation induced intermale aggression and predatory aggression in males are not entirely different.