MORPHOMETRIC VARIATION IN POPULATIONS OF CALOMYS-MUSCULINUS

Adult specimens of Calomys musculinus were selected by using discrimin ant functions. Variation in seven selected cranial mensural variables of these specimens from different localities, different habitats, and different years was examined using multivariate statistical analysis. In males, analysis of geographic trends indicated a relative character homogeneity between localities and a general correspondence between t he samples of the same years. Significant inter-annual variation withi n localities was revealed. In females there was no significant variati on between localities and between yearly samples. It is suggested that the differences in the character states reflect differences in the co urse of development of the males in different years, possibly as the r esult of a demographically driven social selection pressure.