Spatial distribution of scent marks in the red fox [Vulpes vulpes L.]: do red foxes select certain plants as signal posts?

Chemical signals are widely used in inter and intraspecific communication in many animals. The importance of scent marks in communication has led to a variety of strategies in animals to increase the detectability and persistence of their scent marks. We studied the scent marking of foxes in relation to the role of plants as scent posts in a suburban Mediterranean forest in Madrid. Twice a month, from October 2005 to April 2006, we prospected 16 fixed 50  50 m plots, randomly distributed along the study area. We registered all fox faeces and their association to different plants, as well as the potential availability of the different plant species in our study area. Our results indicate that faeces were associated with plants mainly in the clearings, foxes preferred wooden species to grasses as scent posts and holm oak shrubs and rockroses to other wooden species. These data suggest that red foxes select certain plants as substrates for their faeces and pose the possibility that they are guided by searching images when looking for scent posts.