The Use of Urine Marking in the Scavenging Behavior of the Red Fox (Vulpes v uLpes)

The eleven different functions for which mammals use urine marking are reviewed in this paper, and the urine marking behavior of the red fox (Vulpes vulpes) is described in detail. A new hypothesis is advanced that urine marking may serve as a "book keeping system" in the red fox's scavenging behavior. Foxes consistently investigate and urine mark inedible food remnants (e.g., bones, bird wings, and dried out pieces of hide). When a fox re-investigates a marked remnant, the urine mark signals "no food present," and the fox investigates this object for only a brief period of time. This use of urine marking may increase the efficiency of its scavenging behavior, i.e. more food-items found per hour of scavenging. This efficiency may be particularly important during periods of food shortage. The hypothesis is tested in three different experiments, using free-ranging red foxes as subjects. Experiment I establishes that fox do urine mark food remnants. Experiment II shows that foxes investigate for a significantly shorter period of time (P