Demarkation In A Gerenuk Territory: An Economic Approach

Abstract

Patterns of antorbital gland marking by a free-living territorial male gerenuk were investigated in two-week periods in two consecutive years. Marks were removed after the first year and an experimental replicate thus obtained in the second. Marks occurred on conspicuous twigs and 40 % overhung game trails. Most occurred on plants that were frequently eaten. Their height averaged (± SD) 115.2 ± 8.5 and 116.4 ± 10.8 cm in the two years. The spatial distribution of marks, measured using nearest neighbour distances, was significantly non-random. Marks formed an irregular ‘oval’ shape with occasional radiating arms. The results were consistent with predictions based on a model that assumed increasing advantage to the male in marking a larger area, a limited capacity for marking (finite supply of secretion, limited time available, etc.) and the need for marks to be easily detected.