Condition-dependent alternative mating tactics in a sexually cannibalistic wolf spider

Condition-dependent male mating tactics often involve high-quality males capitalizing on the outcome of intersexual selection, whereas low-quality males use behaviors that circumvent female choice to achieve copulation. In the wolf spider Rabidosa punctulata, males display 2 distinct mating tactics: 1) "courtship"--consisting of visual and seismic components or 2) "direct mount"--consisting of males grappling/holding females until they assume a copulatory posture. We tested for condition-dependent tactic expression using both field-collected individuals (representing natural variation in body mass and condition) and individuals whose diet we manipulated in the laboratory (representing extreme divergences in body size and condition). Across both natural and diet manipulated individuals, mating tactic was found to be condition dependent; however, the pattern of tactic expression was initially unexpected. Larger males with better body condition primarily adopted a direct mount tactic, whereas smaller males with poorer body condition primarily utilized courtship. Across all males, copulation success tended to be greatest for the direct mount tactic. We suggest that small, poor condition males predominantly utilize the less-successful mating tactic (courtship) in part due to their increased susceptibility to female cannibalism when attempting a direct mount. Copyright 2009, Oxford University Press.