Visual cues as determinants of perceptual range in root voles Microtus oeconomus

We tested whether the perceptual range of male root voles Microtus oeconomus (Pallas, 1776) could be determined by visual objects in the landscape. This was done by giving single males the choice between three different sized visual cardboard patches randomly arranged around the perimeter of a circle located in agricultural fields. Effects of distance were tested by varying the diameter of the circle. The root voles were able to orient towards patches, but did not choose patches relative to their size. The ability to orient towards patches decreased with increasing distance between the release point and the patches.