The ‘Resources Dispersion Hypothesis’ (RDH, Macdonald, 1983) suggests that, for solitary foragers such as the red fox Vulpes vulpes, group formation is dependent on resource distribution heterogeneity. Our data are compatible with this hypothesis. Rodents, which constituted the main fox prey, were heterogeneously distributed in time and space. Six foxes (three males and three females) were radiotracked continuously from February 1989 to October 1990 (20 months) and we observed spatial sharing between one male and two or three females, considered as members of a ‘spatial group’. Even though their home ranges overlapped between 30 and 100%, members of the group foraged alone and had very few contacts with conspecifics during the night. Furthermore, they partitioned the common home range so that each fox made exclusive use of foraging patches. In contrast, during the daytime, two to four members of the group were frequently in association in a communal resting place. Such associations were observed all year round; they were durable and dynamic. Their advantages were examined. We suggest that they play a role in the maintenance of social cohesion within the group in providing the opportunity for direct contact between foxes. They might also permit increased security through mutual vigilance during resting.