Food habits of the bank vole and phenological phases of plants in an oak hornbeam forest

Abstract

The contents of 139 stomachs of the bank vole trapped in a TilioCarpinetum community were subjected to microscopic analysis. It was found that in spring voles consume mainly green vegetative parts of plants (68%), insects (21%) and seeds (5%). Similar proportions are maintained in summer but the share of seeds increases to 11%. Hence in these two seasons the bank vole belongs to herbivorous-insectivorous animals. In autumn green food fills the stomachs in 38% and tree and herb seeds constitute jointly 40% of food mass. The amount of animal food decreases to 15%. In winter the proportion of green food is identical as in autumn but the share of seeds increases to 56% at the expense of animal food which constitutes barely 6%. It was observed that some herb species are preferred in the period of full development (A. nemorosa) while other are mainly consumed in the phase of slow vegetation. Comparison of the amount of consumed food with its availability indicates that some types of food are specially preferred (e.g. acorns). It was calculated that in the autumn-winter period population of voles including 30—40 individuals/ha may destroy from 1.2 to 1.5% of seed crop. In that period such population consumes under the form of seeds from 27,300 to 36,400 kcal, i.e. approximately 3.9% of total calories present in tree seeds available in 1 ha of Tilio-Carpinetum forest