Study of the trophic relations of small insectivorous mammals

The trophic mechanisms of differentiation and the relationships between various species of small insectivorous mammals, as well as their interaction with the populations of their prey, were studied. The stomach contents of 3225 animals of seven different species (Sorex araneus, S. caecutiens, S. minutus, S. isodon, S. minutissimus, Neomys fodiens, and Sicista betulina) caught in Karelia were analyzed. These species inhabit the same territories, and their main staple food objects overlap almost completely. Thus, the specific nature of their diets is quantitative rather than qualitative. At the same time, the trophic relation of the animals with soil invertebrates becomes weaker from the even-toothed and common shrews to the northern birch mouse. The ecological differentiation and separation of the forage between close species of insectivores were shown to be primarily provided by the different horizons of their habitat (soil and surface layers, grass and shrub tiers, etc.).