[Reproductive success of males of the ICR outbred line during propagation against the background of antigenic stimulation].

Diversity of viruses, bacteria, microscopic fungi, and endo- and ectoparasites is an inevitable environmental factor that influences the host reproduction and that is determined not only by negative effects of infectious diseases but also by activation of protective mechanisms, which provide a confrontation to the pressure of parasites. In the present work, hemocyanin was injected into males of the ICR outbred line in order to study reproductive consequences of antigenic stimulation of males. Intact females were added to control and antigen-stimulated males at the initial stage of antibody formation.

[Factors of stress in a local population of water vole].

Physiological mechanisms of stress have a multiple influence on the implementation of the adaptive capacity of individuals. From this perspective, analysis of factors determining the stress level of animals in changing environment acquires important ecological and evolutionary significance. In the paper the results are presented of long-term studies carried out at a site of irrigative channel being populated by water voles every year.

[Reproductive physiology of the European mink: progesterone profile during pregnancy].

Reproductive physiology of the European mink, an endangered mustelid species, has been so far scarcely investigated. This study confirms that in European mink embryo implantation occurs on the day 12 of pregnancy. Progesterone profile during pregnancy has been compared in European mink and domestic ferret.

[Genetic divergence of Vipera berus and Vipera nikolskii (Reptilia: Viperidae, Vipera) populations in lower Volga and adjacent territories assessed according to the sequences of cytochrome oxidase III 12S ribosome RNA genes].

The nucleotide sequences of mitochondrial genome fragments containing the genes coding for cytochrome oxidase subunit III (COIII) and 12S ribosomal RNA of common European viper and Nikolsky's viper from various habitats (Saratov, Samara, and Penza oblasts; Chuvash Republic; and the Republic of Mordovia) were determined. According to the sequencing data, all samples clustered into two groups except for a number of individuals carrying single mutations in the genes in question. One group comprised V.

[The dynamics of white-backed woodpecker (Dendrocopos leucotos) distribution in the north of the lower Volga region].

Several depressions were identified in the dynamics of white-backed woodpecker (Dendrocopos leucotos) distribution in the southern part of the range in the Volga Region, which were due to anthropogenic deforestation over large areas. One of the last destabilizations occurred in the first half of the 20th century when the southern limit of the breeding range receded northward by 100-300 km. Gradual afforestation in the region resulting from ameliorative measures stabilized the limits of the breeding range and northward expansion of the woodpecker.