Diet differentiation between European arvicoline and murine rodents

Small European muroid rodents are generally divided into species which feed on seeds and/or invertebrates and species which feed on green plant material; however, there is considerable plasticity in feeding behavior among species. Here, we analyze diets of 14 low-latitude rodent species from Western Europe based on published studies. The 77 studies were submitted to principal component analysis in order to compare diet plasticity within and between the 14 species. We observed variations in food composition of arvicoline and murine rodents which are associated with differences in morphology and habitat use. Most arvicoline rodents eat mainly green matter of the herbaceous layers of open habitats whereas most murine species are able to use a greater diversity of high energetic plant tissues from denser habitats, where they can exploit the different vegetation layers. Despite its phylogenetic position among arvicoline rodents, the bank vole (Myodes glareolus) shows morpho-physiological and ecological traits which tend to be more similar to murine species. These intermediate evolutionary characters seem consistent with the fact that bank voles are able to exploit a wide spectrum of trophic resources from low energetic lignified tissues to high calorific invertebrate prey. This results in a very diverse diet, which is intermediate between true herbivorous arvicolines and typical seed- and invertebrate-eating murine species. More investigations on genetic affiliation and ecological driving forces will help understand this intermediate position of bank vole diet, and further investigations among other arvicoline species will help determine if bank voles and other Myodes species are unique.