Potential fitness benefits of group living in the red fox, Vulpes vulpes

For species such as the red fox, spatio-temporal variation in resource availability may promote group living even when the benefits of group formation are not of significant magnitude to promote territorial expansion and delayed dispersal. In this paper we use data from an urban fox population to compare the relative benefits of dispersal and natal philopatry as routes to attaining dominant status and investigate the potential benefits of territory inheritance, alloparental care and reproduction to subdominant individuals. More offspring, of either sex, remained on their natal territory than dispersed. The annual rate of retention of dominant status and the annual mortality rate of subdominant animals was high, such that the majority of subdominant animals never became dominant. The mortality rate of dispersing individuals was also high. The relative success rate of dispersal and philopatry as routes to dominance were broadly similar, although several philopatric offspring became dominant only after their natal territory was divided: in the absence of such changes, dispersal was more likely to lead to dominant status. Thus, it is likely that some other benefit was accrued by philopatric individuals. The majority of subdominants provisioned cubs. This did not increase the number of cubs reared but reduced the level of provisioning by dominants: whether this promoted dominants' longevity is unknown. There were high levels of reproduction by subordinate females and the levels of alloparental care by subdominants of both sexes suggest that there are comparable levels of direct reproduction by subdominant males. (C) 1998 The Association for the Study of Animal Behaviour.