The effect of food choice on the contaminant levels in badgers from floodplains of the River Meuse

Floodplains of the River Meuse in The Netherlands are known to contain contaminants, like heavy metals and PCBs, due to deposition of contaminated sediments from the 1960s onwards. Currently, parts of these floodplains are planned to be reconstructed, mostly into more natural areas. In the current paper research will be presented which was focussed on the badger (Meles meles) and food items (earthworms and corn). Analysis of faeces revealed that earthworms are an important food source for the badgers, although this varied between zero and hundred percent. Furthermore, a higher incidence of corn as food items of the badgers was noticed when compared to the situation between 1960 - 1970, especially in the fall. Analysis of the contaminant levels in earthworm showed in general similar levels of heavy metals and PCBs as those found late 1980s. In corn no contaminants were detectable at relevant levels. In contrast to earthworms, badgers which were believed to have their territory in the floodplains of the river Meuse showed on average a decrease in concentrations of heavy metals and PCBs in the period from 1990 to 2002. There may be several cause for this decrease, and in the current paper it is discussed that changes in food-choice may be of importance