Foraging behaviour of donkeys in encroached pastures in Gran Paradiso National Park, Italy

Abstract

Since the 1950s, land abandonment in mountain areas has caused the progressive encroachment of pastures by woody species (shrubs and trees), resulting in a decrease in forage availability and quality for domestic livestock. The use of hardy species, such as donkeys, could represent a promising method allowing the exploitation of this alternative forage source in the context of silvopastoral systems while contrasting the expansion of shrubs and trees into open pastures. In this study, the feeding behaviour of donkeys was analysed through direct observations by evaluating their selection of different plant species throughout the grazing season. Specifically, we: (1) quantified the consumption of woody plant species; (2) evaluated whether certain woody plants, being palatable to donkeys, are preferentially consumed and their relative consumption increases with their abundance in the feeding station. The results showed a predilection of donkeys for herbaceous forage (89% of the diet), despite highlighting dietary flexibility with a significant ability to consume some woody species and ferns, especially when their abundance in the environment was high. Donkeys could therefore support management strategies aimed at conserving pastures facing shurb and tree encroachment in Alpine agro-ecosystems.