Somatic characteristics and reproduction potential of snow vole and Tatra vole (Rodentia) in Slovakia

Abstract

Somatic features (morphometric or meristic features, i.e., body weight, length of body, tail, hind foot and ear) and reproduction characteristics (number of embryos in uterus, reproduction potential, duration of reproduction season) are the basic attributes of the biology of a species. In the present paper, biometry of somatic characteristics and reproduction potential of two mountain vole species, the Tatra vole (Microtus tatricus) and the snow vole (Chionomys nivalis) which originate from various sites of Slovakia, were investigated. Among somatic features, the body length, tail length, hind foot length, length of ear and body weight were assessed. The highest variability was found in body length and the lowest one in the hind foot length. These characteristics were evaluated separately for sub-adult and adult individuals, and males and females. Values of somatic features and body weight of both species are larger in males than in females. Throughout the life of these rodents, the ratio between the length of tail and length of body does not vary considerably. The reproductive potential of the two species is, compared to other small mammals, very low and the length of reproductive season is shorter in the extreme conditions of the mountain environment. Thanks to a sufficient data set, it was possible to evaluate the influence of altitude on somatic features as well as on reproduction potential of M. tatricus and it was found that the average values of somatic features and body weight increased with increasing altitude.