Exploitation of Food Resources by the Eurasian Badger (Meles meles) at the Altitudinal Limit of Its Alpine Range (NW Italy)

Abstract

Food availability has been suggested to be the main factor shaping the altitudinal limits of species distributions. We analyzed the badger (Meles meles) diet in the western Italian Alps and, particularly, at the altitudinal limit of its range, with the main aim of highlighting any reduction in earthworm availability with altitude which could act as a limiting factor for badgers. Earthworms were by far the main food resource of badgers, followed by fruit. The two-month importance of these two items in badger diet was inversely correlated. Earthworm consumption was negatively correlated with air temperature. The seasonal pattern of earthworm use by badgers seemed to be influenced by the reproduction and estivation times of some epigeic species, rather than by climatic conditions per se. The eating of fruit by badgers was at least in part independent from the availability of earthworms. The badgers' efficacy in preying upon earthworms also in adverse conditions and their reliance on a wide variety of food resources suggest that worm availability might play a minor role in shaping the altitudinal limit of the species on the Alps.