The effect of increased food supply on the body growth rate and survival of bank voles in an island population

Abstract

Abstract Studies were made of the effect of increased food supply on the growth rate and survival of members of an island population of the bank vole Clethrionomys glareolus (Schreber, 1780), for which purpose comparison was made of the mean weight of individuals, increase in their weight in dry and wet habitats, and survival during the period 1966-1969, when the population was living in natural conditions, and from 1973-1974, when the voles were supplied ad lib. with oats. It was found that during the supplementary feeding period the mean weight of the animals was significantly greater than in years when they fed on the natural food supply only. From 1966-1969 increase in weight was greater in the animals living in the wet habitat. During the experiment, growth rate was uniform in both dry and wet habitats. Survival between trapping series was greater from 1973-1974 than from 1966-1969.