THE SEASONAL DYNAMICS OF DEMOGRAPHIC AND SPATIAL STRUCTURE IN THE POPULATIONS OF TAMARISK GERBILS (MERIONES TAMARISCINUS) IN SOUTHERN KALMYKIA

The method of marking and recaptures on a study area of 7.4 ha and adj acent territory of 0.5 sq. km. was used to obtain the data on seasonal dynamics of demographic and spatial structure of a local populations of gerbils. The data on the sex-age structure of the population, repro duction, mobility of individuals, size and structure of home ranges ar e given. The high rate of seasonal and yearly renovation of the reside nt part of the population (up to 90%) was revealed. The adult females occupy isolated home ranges in all the seasons. The home ranges of adu lt males throughout the reproductive period are considerably overlappi ng among themselves and with the female ones and are considerably larg er than these latter. The home ranges of some adult males are formed b y several separate areas lying far from each other and connected with home ranges of receptive females. These males are characterized by sig nificant moves whithin the range of population (up to 700 m or, probab ly, more). The ''drift'' of home ranges of resident individuals is rev ealed, its possible causes are discussed. In autumn, the gerbils irres pective of their sex and age occupy isolated home ranges to some exten t overlapping only in some part of youngs of the year. The mean areas of the home ranges in autumn are as follows (M +/- SE): males (n = 23) - 1140 +/- 260 sq. m, females (n = 33) - 1470 +/- 200 sq. m. The stra tegies of the use of space by the individuals of different sex and age are discussed. The obtained data confirm the existing assumption abou t the solitary mode of life of tamarisk gerbils.