Local and seasonal variations of roe deer diet in relation to food resource availability in a Mediterranean environment

摘要

Feeding behaviour patterns of European roe deer are well known but not in their southern range, where in contrast to Central and northern Europe the climate is characterised by mild winters, but hot and dry summer months. Spatial and temporal variations of the roe deer diet were investigated by analyses of 597 faecal samples in a coastal area in Italy. The aim was to evaluate the adaptive strategies of dietary intake to seasonal availability of different forage types in areas of fairly natural Mediterranean scrubwood and different areas dominated by agricultural habitats. A wide range of plant taxa (151 species/genera) was used, belonging to eight categories. A gradient was found from a diet dominated by woody plants and fruits in natural habitats to one characterised by cultivated plants in the agricultural areas. Usage of forage categories in areas dominated by woodland was proportional to their availability, whereas diet selection was found in the agricultural habitats, particularly marked in summer, the time at which food quantity and quality decreased due to harvest and drought. As to seasonal variation, the summer and autumn diets included more deciduous browse, whereas the winter diet was characterised by an increasing use of cereals and grass. In most areas, half-woody browse and fruit were preferred; grass and cereals were used less than expected by their availability. Most probably, selective behaviour patterns are linked to the difference of quality between plants together with their variable abundance, which is more evident in agricultural areas than in the woodland.