OPTIMAL PATTERNS OF SCENT MARKS IN KLIPSPRINGER (OREOTRAGUS-OREOTRAGUS) TERRITORIES

The distribution of preorbital gland scent marks and dung middens with in three territories of wild klipspringers in Zimbabwe are described. Nearest-neighbour analyses revealed that scent marks were distributed non-randomly and in a rough ring some distance within the territory bo undary. Marking densities were greatest at about half the territory ra dius. In two territories, marking densities were shown to be sensitive to intrusion pressure at the periphery, being higher along contested boundaries than where territories were not contiguous. Marks were plac ed on branches facing neighbouring territories, where they are more li kely to be detected, along contested boundaries but not in other areas . An analytical model is developed which tests the efficacy of scent-m arking strategies along the continuum between extreme hinterland and e xtreme perimeter marking. This shows that the optimal position for a r ing of scent marks is at 0.78 of the territory radius and is the produ ct of a trade-off between maximizing the probability of mark detection by intruders and minimizing the cost of intrusion.