Variability of the Ecological and Morphological Characteristics of Field Vole (Microtus agrestis) in the Southern and Middle Urals

Russian Journal of Ecology - The variability of the ecological and morphological characteristics of the field vole was studied on samples collected in its two localities of the Southern Urals and...     

Genomic instability in the bank vole: Population-ecological aspects

Chromosome aberration frequency in relation to population dynamics and demographic parameters was studied for six years in a bank vole population in the Middle Urals. The frequencies of structural chromosome aberrations, chromatid gaps, aneuploidy, and polyploidy in males and females and in animals of different ages did not differ significantly. In the breeding period, the frequencies of structural aberrations and changes in chromosome number increased in the somatic cells of voles. Highly significant differences between the levels of chromosome instability in different years manifested a tendency toward a negative correlation with population size.     

Variability of the Chewing Surface Pattern of M3 and M1 Molars in a Cyclic Population of the Bank Vole

Russian Journal of Ecology -     

Variability of Demographic Parameters in a Cyclic Population of the Bank Vole (<Emphasis Type="Italic">Clethrionomys glareolus</Emphasis>)

Analysis of demographic parameters in a local bank vole population has shown that different relationships exist between them. The level of population abundance is directly correlated with the proportion of sexually mature juveniles, the length of the breeding season, and the age of overwintered individuals. The duration of the breeding season shows a delayed dependence on population abundance in the previous year. Variation in the average age of overwintered voles at different phases of the population cycle is characterized by a delayed dependence on the length of the breeding season in the previous year. Intrinsic factors generate the cyclic dynamics of parameters, while extrinsic factors can modify their dynamics.     

The Diet of the Great Gray Owl,Strix nebulosa,at Different Levels of Prey Abundance during the Nesting Season

Variation in the diet of the Great Gray Owl, a specialist predator, at different levels of prey abundance in different biotopes was studied in the middle Transural region. Microtus voles were found to be the main prey, with shrews being alternative prey. In different plots, two types of change in the diet were observed during the nesting season: (1) substitution of Microtus voles inhabiting meadow biotopes by Microtus voles characteristic of forest habitats, and (2) substitution of the latter by shrews.