The spring diet of badgers in two contrasting habitats in the Netherlands
In Northern Europe the badger (Meles meles) uses earthworms as a primary food source and is sometimes described as an earthworm specialist. In the Mediterranean, badgers tend to be generalists, and insects and fruits make a larger contribution to their diet. In this study we test the hypothesis that the proportion of earthworms in badger’s diets is enhanced by a higher availability of earthworms. We do so by comparing the composition of the spring diet of badgers in two habitats with differing earthworm availability (biomass earthworms; 74.9 kg ha-1 vs. 7.3 kg ha-1). The dietary composition was determined by fecal analysis. Between March and May 2007 fresh fecal samples were collected on a weekly basis from an earthworm-rich (Veluwezoom National Park; n=85) and earthworm-poor habitat (Hoge Veluwe National Park; n=79) in the Netherlands. The main food classes observed were earthworms, fruit, insects, larvae, amphibians and other vertebrates. Samples collected from Veluwezoom showed a relatively higher volume of earthworms than those from Hoge Veluwe (46.4% against 36.0%). However our results show that the badgers in the earthworm-rich habitat eat only 30% more earthworms, despite earthworms being ten times more available in this habitat. Earthworms are the primary food for badgers in both habitats and are supplemented with seasonal (beetles, larvae) and local (rabbits) resources, depending on their availability. The trophic niche of the Hoge Veluwe provided a more varied diet (BA = 0.79) than that at Veluwezoom (BA = 0.41) and badgers feeding from the earthworm-rich habitat, Veluwezoom, (CH = 0.80±0.19) had less varied diet than those feeding from the Hoge Veluwe, an earthworm-poor habitat (CH = 0.55±0.31). Although badgers are more generalist feeders than specialists, they do seem to prefer earthworms to other food.