No peace for estrous topi cows on leks

Male coercion, such as harassment, may be considered the third main component in sexual selection alongside male competition and female choice. In this study on lek-breeding topi antelopes (Damaliscus lunatus), I investigate whether female mating preferences have consequences for male investment in harassment and whether harassing males are more likely to succeed in mating. I then address the question of whether lek evolution in topi can be explained by harassment avoidance. Judging from mating rate, I found that female topi antelopes in estrus preferred lek males to resource defenders. In contrast to lek males, resource defenders demonstrated significantly higher harassment rates before they succeeded in mating than when they did not, and the precopulatory harassment rate was significantly higher on resource territories than on lek territories. After mating on resource territories, harassment dropped to low levels. Thus, resource defenders, but not lek males, seem to employ harassment as a strategy to coerce females to mate against their preference. However, by using various measures of harassment intensity, overall estrous females were found to experience higher harassment levels on lek, and chases by intruders were relatively rare on all territory types. These findings suggest that harassment avoidance is unlikely as an explanation for lek evolution.