Mating strategies of topi bulls: getting in the centre of attention

In lek-breeding ungulates, only some males defend clustered lek territories, and others defend dispersed territories or are nonterritorial. In this study of lekking topi antelopes, Damaliscus lunatus, we measured male mating benefits directly by observing matings and investigated why the alternative mating strategies coexist. A multivariate analysis showed that proximity to the lek centre had an overriding, positive, effect on male mating rate. With increasing distance to the lek centre, proximity of a territory to a drainage line became increasingly important in enhancing male mating success. On the other hand, costs of lekking were suggested by higher hyaena density on leks, relatively poor body condition of lek males, and more frequent agonistic encounters, with central lek males more likely to sustain bleeding wounds than others. Probably as a consequence of the intense competition for central lek territories, males defending such territories were larger than others and, judging from horn wear, they were also older than resource defenders. Not only did males defending central lek territories achieve the highest instantaneous mating rate and resource defenders the lowest, but the same order was also likely for overall lifetime reproductive success when we took territorial tenure into account. These results suggest that male mating strategies are phenotype limited, as demands on male quality increase with proximity to the lek centre. (C) 2003 Published by Elsevier Science Ltd on behalf of The Association for the Study of Animal Behaviour.