Behavior Of Wild Male Mus Musculus

The first or second male generation of wild house mice doaesticus Ruddy) caught in England were tested for the development of behaviour from weaning to adult, the characteristics of adult male (including dominant and subordinate), the role of substrate odour in maintaining social tolerance between male mice, the effect of kinship on behaviour of male mice, the ability to discriminate between unfamiliar individuals on the basis of kinship, parentage test using DNA fingerprinting etc. These studies are of special interest or update research field in animal behaviour. Four kinds of nonsocial behaviour and sixteen kinds of social behaviour were observed and recorded in both duration and frequency. The main conclusions of this thesis are as the follows.1. After the unrelated weaning male mice were housed together for 12 days, they formed their hierarchy (dominant/subordinate) at the mean age of 52.08 days.2. After the related weaning male mice were housed together for 26 days, they formed their hierarchy (Dominant/subordinate) at the mean age of 61.42 days.3. The changes of other non-agonistic behaviours took place corresponding to the forming of hierarchy, for examples, the decreasing of selfgroom and huddle, the increasing of sniff ano-genital and allogroom.4. Only four of 20 behaviours were showed by male mice after weaning, including allogroom, rattle, chase, and flee.5. It is probable to predict the coming dominant male among male weaning mice on the basis of behavioural index. In unrelated male group, the coming dominant male were more active in social investigation in distant than the coming subordinate. In related group, the coming dominant male were more active in sniffing sawdust substrate and climbing than the coming subordinate.6. Besides the significant differences in agonistic behaviour between dominant male and subordinate, sniffing substrate, social investigation and urine marking of dominant male were also significantly higher than that of subordinate. The subordinate preferred to touch other subordinate rather than the dominant male.7. There was little aggression of dominant male under all conditions (less than 40 seconds against each subordinate per hour observation), contrasting with the high levels of aggression commonly recorded between unfamiliar individuals and neighbouring in the other studies.8. Within the 1-hour observation period, the agonistic and social investigation decreased gradually, while the amicablebehaviour increased gradually. The first 10 minutes of 1-hour observation was the most important for observing the behaviour.9. On the basis of non-agonistic behaviour, especially social investigation and touching, it was probable to discriminate the dominant male in the male group whose hierarchy was unclear by discriminant analysis.10. 23-hour physical separation resulted in the decreasing of sniffing sawdust substrate and climbing, and the increasing of agonistic behaviour and social investigation. However, the dominant maintained most of its behaviours at the original level. The isolation mainly caused the subordinate to change its behaviours, particularly the behaviour towards other subordinate, due to the increasing aggression of himself.11. Mice which were physically separated but maintained with group substrate odours thus appeared to be recognized as familiar group members and tolerated. However, there were difficulties on recognizing males in unrelated groups when mice had not met for 23 hours.12. Removal of substrate odour cues appeared to increase this difficulty further, producing a significant bias in aggression towards unrelated males throughout the time males spent together. In unrelated groups "dispersed" subordinate were consistently attacked by "resident" males (i.e. dominant male and "resident" subordinate) more than "resident" subordinate.13. Dominant males in related groups initially investigated "dispersed" half sibling more than the resident males, but recognized them as familiar group members and did not attack.14. The discrimination between group member of male mice might be achieved by individual odour, not the group odour, and substrate odour might play more important role than body odour in the communication.15. The role of substrate was to help maintain the group stability, i.e. the mutual tolerance. The main function of subordinate substrate was used to communicate with dominant male and other subordinate, and to be recognized as group member.16. There were many significant differences in behaviours between unrelated and related groups when the groups were just set up, such differences as the less sniffing substrate, investigating in distant and agonistic behaviour, and the more investigating nose and body in related groups, compared to the behaviour in unrelated groups. But the differences disappeared in about 3 weeks when the group members became more and more familiar.17. Kinship still existed even both unrelated or related group â– embers lived for a long time. The differences in behaviours between unrelated and related groups was unobvious under thecondition of undisturbed living environment, but once being disturbed, even 24-hour isolation, or removing one individual's odour in substrate, the differences became clear.18. The kin biased behaviours existed only on the first day when three unfamiliar weaning mice were housed together, paternal sibling investigate the ano-genital and body of unrelated male â– ore than the unfamiliar paternal sibling, this ability to discriminate related and unrelated male mice disappeared then.19. The unfamiliar paternal half-sibling might be discriminated by the common cues of paternal kinship through "phenotype Matching" or "recognition alleles". If the mechanism was the former, the template was of paternal characteristics, not maternal. The "kin recognition" template of phenotype matching here might be formed by two ways, one learning from self, the other learning from littermates.20. The similarity coefficient of DNA fingerprinting was not an ideal standard to identify the relationship among offspring and their putative parents, due to many shared bands among them. It was easy to find the real parent of the offspring on the base of the analysis of band sharing among offspring and their putative parent. DNA fingerprinting hybridized by mouse probe under low-stringency hybridization condition generated a novel and highly individual diagram for parentage test.