Skull variability in the common mole rat Spalax microphthalmus (Spalacidae, Rodentia). 2. Variability of females, sexual dimorphism, and age variation [Russian]

摘要

The variation of 44 skul parameters (measurements) in 182 specimens of the common mole rat Spalax microphthalmus Guld. captured from the same population (Kursk district, Russia, 51 degrees N, 36 degrees 40' E) was analyzed for 1988-1996. The main aim of the work was to check a suggestion on the parallel variability within one sexual group and that related to sex of individuals (sexual dimorphism) in accordance with the hypothesis-of the par. allel morphological variability at various levels, from population to species, and above (Pavlinov et al., 1993). The data were analyzed by nonparametric methods (multidimensional scaling, cluster analysis). The method of analyzind was given in Report 1 (Puzachenko, 2001), attesting to the presence of two groups (large and small) differing in the absolute size of the rostral skull part. The given paper deals with studies of the variability in adult males, sexual dimorphism, and age variation. A probable effect of morphological dimorphism on the population demographic pattern and population ecology is discussed. The skull size correlates with the mass and linear sizes of the animal's body. The difference between "large" and "small" in males exceeds 100 g. Large males took part in reproduction more often and occupied a leading position in the social population hierarchy.