Habitat, food availability and group territoriality in the European badger, Meles meles.

Since European badgers (Meles meles L.) form non-cooperative groups in parts of their geographic range, but are solitary elsewhere, their social systems have been at the centre of a debate about the evolution of group living in the Carnivora. In a recent review of models of non-cooperative sociality, Woodroffe and Macdonald (1993) presented evidence in favour of two hypotheses, which suggested that badger groups might form because either the distribution of blocks of foodrich habitat, or the economics of excavating new setts, prevented the division of group territories into individual territories. We present data upon the response of badger spatial organisation to a reduction in food-patch dispersion, brought about by the conversion of carthwormpoor arable land to earthworm-rich pasture over a 15-year period. This change in the distribution of earthworm-rich habitats was accompanied by territory fission, facilitated by the excavation of new setts. This indicates that the availability of sett sites had not constrained territory size at the start of the study. However, sett distribution did define the size and configuration of the daughter territories. We also show that variation among territories in the availability of food-rich habitats was reflected in the reproductive rates and body weights of the groups that inhabited them, although there was no detectable effect upon group size.