A spatial analysis of a population of red fox (Vulpes vulpes) in the Dutch coastal dune area

The red fox Vulpes vulpes is usually classified as being territorial, dispersing or transient. Past studies have focused almost exclusively on territorial or dispersing foxes, leaving transient foxes out of the analysis. In this paper, we present spatial-statistical methods for the classification of free-ranging foxes, using 95% fixed kernels and 100% minimum convex polygons. By means of these procedures we classify individual foxes on the basis of their spatial behaviour, using home-range size and home range shift. Also, we make a methodological comparison between these classification procedures and interpret the composition of these classes ethologically, The procedures apply to a sample of 24 foxes, radio-tracked in the dune area of the Netherlands from January 1997 to June 1999. We analysed size of home range and successive 3-month overlap using a geographical information system (GIS). Classifying the sample using 95% fixed kernel home ranges resulted in two classes of foxes: a class of 20 territorial foxes with relatively small home ranges (< 250 ha), and a class of four dispersing and transient foxes with relatively large home ranges (400-600 ha). This study shows that a fox population can be divided into different classes of individuals in a quantitative statistical way, honouring measured characteristics. This is a clear extension of more informal ways relying on expert judgement applied so far.