High population density in bank voles stimulates food hoarding after breeding

Abstract

The effects of conspecific density (i.e. risk of intraspecific competition) on hoarding behaviour were studied in breeding pairs of bank voles,Clethrionomys glareolus.I simulated high population density by using odours of conspecifics, to exclude the direct effects of exploitation or interference competition for food. The pairs of bank voles hoarded only at the end of their breeding season. Hoarding was not correlated with whether the voles had a litter during the experiment or their litter size, but was more likely at the high population density and for pairs with small females. This may indicate that smaller females especially make caches in the autumn, possibly to ensure better winter survival under high population density. I discuss the hoarding behaviour of bank voles in relation to their territorial behaviour and food resources during the breeding season and predictable population changes during winter.