A unified model of social organization, spatial distribution, and demographic parameters in the bank vole was developed. It is based on social relations among females, among males and also between reproductive females and males. In the model, social status and reproductive condition of an individual depend exclusively on interactions with its nearest neighbours. A result of interactions between two neighbours remains "local", i.e., it cannot affect other, more distant individuals. The simulated variables show similar trend and scatter as those found in a growing real population of the bank vole. The relevance of the model for theories of population dynamics is discussed.

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Eight species of carabids (six of them represented by two subpopulations) were sampled. It appeared that the mean number of ripe eggs in the ovaries could be regressed on the specific body weight (ranging from 20 to 285 mg dry wt.): the mean decreased in heavier species, and was higher in the autumn breeders than in the spring breeders. The rate of disappearance of ripe eggs from ovaries, estimated at the end of the reproductive season, was regarded as the egg deposition rate. It turned out to be inversely correlated with the actual female mobility. The calculated fecundities in the separate species and subpopulations with the same type of development could be satisfactorily regressed on the specific body weight. Thus, the developmental type, the specific body weight, and actual female mobility are involved in egg production and deposition.

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