Splitting hairs: How to tell hair of hares apart for predator diet studies

Hares are a major prey for many carnivorous vertebrates worldwide. Their occurrence in the diet of predators is mostly assessed through the analysis of indigested remains (especially hair) in faeces or pellets. In Italy, four hare species are present, locally occurring in sympatry, and several studies confirmed they are preyed upon by 15 carnivorous vertebrates, overall. A reliable identification of hare species in their diet is only possible if specific diagnostic keys of their hair are available. To provide diagnostic features of the four Italian hare species, we collected 218 hair samples from 37 individuals belonging to 13 hare populations. Samples were measured and analysed at the microscope; five indices were assessed. Hair indices of morphology differed significantly across the four species, both in the cortex and in medulla structure. Species discrimination through hair may be crucial especially if the range overlap among hare species will increase, due to environmental/climatic changes and/or human management actions (e.g. restocking).