Biological Faculty, M.V.Lomonosov Moscow University, Vorob'evy Gory, Moscow 119899, Russia

Abstract

During 25 years ecology and population dynamic of two brown frog species (Rana temporaria and R.arvalis) in Moscow region, Solovki island and South Ural were studied. We compared life cycles characteristics, namely biotope preferences, diet, migration, enemies, hibernation places using own and available literature data. Then we analyse how these parameters are changed among the species area and ecological niches were compared. We found that these two species do not compete in any stage of life cycle. Ecological niches are very closed and differences are determined generally by abiotic factors. So, R.temporaria prefers more wet biotope and more sensitive to acidity (low pH value). Differences in spawning time do not associate with interference in spawning places. We conclude that interspecific competition did not take place neither in the past nor in present and the reason of differences in ecological niches are determined by separate ways of evolutionary development of these species.