BEHAVIOR OF HOUSE MICE IN SEMICONFINED CONDITIONS - INFLUENCE OF SPATIAL SEPARATION AND POPULATION-SIZE

Quantitative scares for 4 behavioural patterns, especially those of an antagonistic nature, were recorded from wild individual of Mus muscul us musculus Linnaeus, 1758 living in semi-confinement in an outdoor en closure divided into four pens. The enclosure was ''permeable'', in th at mice were able to move between pens and between the enclosure and t he outside. The population was monitored by the capture-mark-recapture method. In the spring of 1988 and 1989 the behaviour of mice trapped in the enclosure was studied in unisexual encounters in a neutral aren a. There were no significant differences in scores for behaviour in re lation to the degree of spatial separation of the places of capture of individuals paired together (except in the number of attempts to esca pe noted for females in 1989 and the total activity noted for males in 1988). Males and females did not differ significantly in scores for a ggressive behaviour, but mice were more aggressive and more active in 1989 when the population in the enclosure was smaller, than in 1988, w hen it was larger.