Resource selection by roe deer: Are windthrow gaps attractive feeding places?

Windthrow gaps are often regarded as attractive feeding places for roe deer Capreolus capreolus L. because they are considered to provide more forage than undisturbed forest stands. However, for temperate lowland forests in Central Europe, differences in the quantity of forage in gaps and undisturbed forest stands have not yet been quantified. In two deciduous forests in northern Switzerland, we studied seasonal forage availability in undisturbed forest stands compared to windthrow gaps, with the timber either cleared or uncleared, created by the storm Lothar in 1999. To assess the attractiveness of windthrow gaps for foraging roe deer, we measured seasonal browse consumption by roe deer in these three forest structure types. The amount of available forage mainly varied between seasons and, to a lesser extent, between forest structure types. Windthrow gaps did not generally provide larger quantities of food resources than adjacent undisturbed forest stands. Browse consumption was not directly related to forest structure type, but seems to be dependent on the vertical structure of the understory vegetation (herb/shrub layer). Within forest structure types, browse consumption was constant over seasons, but browsing on individual plant species varied according to season and study site.