THE MAIN FACTORS DETERMINING THE DOMINATI ON OF FEMALES IN THE GROUPSOF COMMON VOLES MICROTUS-ARVALIS FROM OBSCURUS OF DIFFERENT SEXES (RODENTIA, ARVICOLINAE)

The formation of social structure in common voles, form obscurus, was studied under laboratory conditions from January to August, 1989. Two males and two females were placed in an enclosure. 12 experiments were carried out. A complex of indices (age, body mass, sex ratio in litte rs, phase of estrous cycle and the parameters of behavior in open fiel d and in the pairs placed on neutral territory) was studied to reveal factors determining the domination of females in groups. The levels of exploratory activity, emotionality and stress-reactivity are the most significant factors determining the domination. The manifestation of territorial behavior depends on individual features and physiological state of animal, in particular, on the phase of estrous cycle. The rea lization of reproductive potential in females is influenced by the pre sence of stable social structure and the composition of groups.