Effect of landscape type, elevation, vegetation period, and taxonomic plant identification level on diet preferences of Alpine mountain hares (Lepus timidus varronis)

Diet is important for understanding the ecology and evolution of populations. When examining animals' diets, the lowest taxonomic rank (i.e., species level) is generally used. However, it is questionable whether dietary description varies with respect to the plant taxonomy or with the extent of plant species diversity in landscapes. We studied the diet of the Alpine mountain hare (Lepus timidus varronis) by analyzing the botanical composition of fecal pellets and comparing the results with the availability of food plants. Overall, Alpine mountain hares selected ligneous plants, whereas grasses were neutrally consumed or avoided. Plant identification at the genus and family level revealed the most information, whereas little additional information was gleaned by identifying food plants at the species level. In low-diversity spruce forests and at higher elevations, hares exhibited greater diet breadth compared to high-diversity vegetative mosaics or at lower elevations, even if they had access to the same types of plants. This is likely due to the hares' need to diversify their diet when plant quantity is low. Greater diet breadth and selection of a larger number of different plant types at the beginning of the plant vegetation growth period suggested that more food plants suitable for Alpine mountain hares were available during this time compared to the end of the vegetation period.