Scale-dependent trade-offs in foraging by European roe deer (Capreolus capreolus) during winter
We studied food preferences of and patch and habitat selection by European roe deer (Capreolus capreolus) by snow-tracking radio-tagged individuals. To account for the possible biases caused by patch/habitat selection on measures of food preference, we adopted a new method in which diet choice is compared with availability within each forage patch successively rather than to some home-range or study-area average. There was no difference in food preference between males and females or between day and night. When compared with that in random sites 50 m from feeding sites (patch scale), selection was random with regard to cover; however, the food availability index was higher for feeding sites than for random sites. Roe deer selected feeding sites with more cover during cold weather, whereas the food availability index had no effect at this scale (habitat scale). Roe deer selected more open habitat and feeding sites closer to human settlement at night and as snow depth increased. Females tended to select foraging sites that were more hidden than those of males. There was direct evidence of a trade-off between selection of food availability and both canopy cover and distance to human settlement but not between food availability and concealment cover.