Influence of predator odour on the feeding behaviour of the root vole (Microtus oeconomus Pallas, 1776)

An experiment carried out under laboratory conditions addressed the influence exerted by the odour of a stoat, Mustela erminea Linnaeus, 1758, on the feeding behaviour of a root vole, Microtus oeconomus Pallas, 1776. Specifically, the impact of the odour on the chewing of rowan (Soi-bus aucuparia) shoots and consumption of food pellets by voles that were not sexually active was observed over a 14-day period. The floors of cages with individuals from the experimental group were sprinkled daily with a distilled-water rinse from a glass clamber in which a stoat had been confined, while cages holding control individuals were sprinkled with distilled water only. The uptake of food was monitored daily by checking the degree to which shoots had been chewed, as well as the amount of food pellets consumed. Stoat odour caused a significant reduction in chewing of the shoots but did not affect the amount of food pellets eaten. There was no significant influence of the scent on body mass, which suggests that the assimilation of food was probably the same for voles in the experimental and control groups. Long-term exposure to stoat scent was not associated with changes in food consumption over time, which suggests that the voles had not become habituated to the presence of the odour over the 2-week period. It would therefore seem that the stoat scent affected the specific feeding behaviour of the voles rather than their overall consumption level.