Diets of the Eurasian badger Meles meles were studied by scat analysis in three localities of eastern and central Poland, representing pristine forests and rural landscapes with little wood cover. In spring, earthworms constituted 82–89% of biomass consumed by badgers in all localities. In summer and autumn, the proportion declined to 56% in the pristine forest, and to 24% in the mosaic of forests, fields, and orchards. Supplementary resources at this time were amphibians (in forests) or garden fruits (in a rural landscape). Literature on badger diet composition in Europe showed that earthworms and vegetable matter were the dominant food types of badgers, but their roles changed with latitude. The share of earthworms grew from nil at 37–40°N to 40–70% at 55–63°N; the opposite trend was observed for vegetable food. Also, of two major supplementary resources, vertebrates were taken by badgers more often at northern latitudes, and insects in the south. In consequence, the food niche of badgers was broadest at 45–55°N and became narrow at both lower and higher latitudes. Moreover, in the temperate zone of Europe, the degree of habitat transformation by humans significantly affected badger feeding habits. In forests, badgers relied predominantly on earthworms (on average, 62% in diets). In farmlands and pastures, earthworms and plant material (usually garden fruit and cereals) played equally important roles (34% each). This biogeographical pattern of feeding habits can be explained by variation in abundance and availability of earthworms.
