[Spatio-ethological aspects of interactions between small mammals and wood ants]

Mechanisms of interactions between species present one of the central problems of contemporary behavioral and evolutionary ecology. Field observations of possible resource redistribution and mutual behavioral adaptations between representatives of different guilds with substantially overlapping niche parameters are, so far, few. Using the methods of small mammals censuring, with account for their mobility and burrowing activity, at the sites with high and low dynamical density of wood ants Formica aquilonia, as well as in anthills proper, spatial interactions between these animals are revealed for the first time which are based on seasonal transformations of topic competition and synoecism. Species composition and domination structure of small mammals communities appear to be similar in those territories controlled by F. aquilonia and almost free of them. However, judging by animals’ spatial distribution and activity it can be suggested that wood ants, being a disturbing factor, markedly reduce the numbers and burrowing activity of small mammals in their territory and, apparently, hinder mammals dispersion. During seasonal resting of ants, when they move down into the soil, anthills attract a lot of small animals: from October to May up to 84% ant nests are burrowed by murine rodents and insectivore mammals. It seems to be possible that there are trophic relationships between small mammals and wood ants, with mammals consuming nest substrate as well as insects themselves.