An Experimental Study of Aggression in Captive European Rabbits, Oryctolagus Cuniculus (L.)

Abstract

Aggression in wild and domestic New Zealand White European rabbits, Oryctolagus cuniculus, has been studied in the laboratory. The experimental procedure was to introduce a strange animal into the pen of another rabbit. All possible combinations of sex and type of breed were made in the 580 tests each lasting 150 seconds. Attention was paid to the occurrence of chasing, biting, ripping and mounting. The outcome of the confrontation was classified in terms of win, lose or draw. The data collected has been subjected to statistical analysis. All rabbits, irrespective of type or sex, were found to be able to fight and to be prepared to defend their own home. The incidence of victory of home animals over introduced ones was highly statistically significant (P<0.001) for all combinations of contesting animals with the exception of those in which New Zealand White does were confronted with introduced New Zealand White males. The reversal of home and introduced positions of two individuals reversed the outcome of the contest. Aggression was found to be equally prevalent in both sexes and inter-sexual fighting occurred just as frequently as fighting between members of the same sex. New Zealand White rabbits engaged in mounting more frequently than the wild animals but on the whole domestication did not eliminate their ability to fight. Domestic females paired together and domestic males paired with introduced wild animals of both sexes fought less frequently and less viciously amongst themselves than the other pairings. Rabbits introduced into foreign pens stamped more frequently than home animals. It seems that depending on circumstances stamping may be a part of different behaviour patterns and not necessarily a component of agonistic behaviour. The behaviour of rabbits towards anaesthetised ones placed in their pens was studied and the results suggested that the lack of movement and resistance lessened the severity of the attacks by the home animals. The home individuals frequently chinned, licked and scratched the introduced anaesthetised rabbits although these forms of activity were absent during the confrontations with untreated animals. In the Appendix by M. L. DUDZINSKI & C. B. H. EDWARDS the data is analysed by the principal components method. This method of analysing multivariate data allows the geometrical demonstration of congregations - clustering - of separate behavioural components which is useful in revealing the relation between different categories of behaviour as well as the behavioural characteristics of separate groups of animals.