Thirteen badgers and 20 foxes were radio-tracked in the Wytham Estate, Oxfordshire, between 1981 and 1983. Thirteen badger and 10 fox groups were identified from radio-tracking and bait marking. Badger groups (mean size 1982: 4.45, 1983: 5.82) occupied contiguous territories (size: 22-75 ha) with boundaries marked by latrines. Seasonal variation in marking intensity and choice of marking sites presumably were responses to changing intrusion pressure. Fox groups (mean size: 2.6) occupied stable territories (size: 22- 104 ha) with little overlap. Faeces deposition by foxes facilitated territory marking. Earthworms (Lumbricus terrestris) dominated the diet of badgers (63 % estimated dry weight EDW, faeces), followed by cereals, fruits and other Invertebrates. Diet was highly variable between groups and seasons. For foxes, lagomorphs (20 % EDW) and earthworms (33 % EDW) were the most important prey, followed by scavenge and fruits. Variation in diet between groups and seasons was marked in lagomorphs but not earthworms. Multlvarlate analyses of habitat parameters revealed a low-dimensional 'resource space' that could be divided into conventional habitat categories. Censuses of prey species indicated that resource presence varied consistently between habitat categories. Key habitats occurred at fairly constant proportions in territories of both species) their dispersion partly determined the configuration of territory boundaries. The proportions of specific habitats per territory were correlated with the proportions of certain prey items in diets. space use by individuals was analysed by spatial autocorrelation methods, variation in space use by foxes was attributed to variation in resource dispersion. In contrast, individual badgers were similar in their use of space. Here, small-scale heterogeneity in intensity of use may reflect local earthworm availability, in one studied fox group, males and females differed in range use. Individuals in one studied badger group coordinated their use of space probably to minimize foraging interference. It is suggested that group living in Wytham badgers is a response to defending resources, and a model is proposed to explain how the spatial and social organisation of male and female badgers relate to the characteristics of the resources they require.