DRIFTING TERRITORIALITY IN THE RED FOX VULPES-VULPES

(1) The spatial organization of a population of red foxes, Vulpes vulpes L., living in the city of Oxford was investigated and contrasted to that of a neighbouring population in the surrounding suburbs. (2) Both populations were organized in social groups, each of which occupied an exclusive territory. While territories in the suburbs were spatially stable, those in the city drifted in location continually, but they did so in such a way that the juxtaposition of neighbouring groups remained essentially unaltered across generations of occupants. (3) The hexagonal pattern of city ranges moved at a rate equivalent to the complete displacement of an average range (38.8 ha) every 13 months (3.01 ha month-1), although drifting was more pronounced from November to April. City and suburban foxes had comparable diets and ranges of the same order of magnitude; the mobility of city foxes was associated with social instability due to a higher turnover of the population and a lower proportion of barren vixens. (4) As a response to constraints of the city environment not encountered in the suburbs, synchronous drifting of city ranges represents a rapid modification of behaviour since the urban niche first became occupied by foxes in the 1930s.