COSTS AND BENEFITS OF MALE-MALE COMPETITION IN THE ORB WEAVING SPIDER, NEPHILA-CLAVIPES

1. The reproductive benefits and predatory costs of male-male competition were studied in the orb weaver, Nephila clavipes. During the breeding season adult males search for females, and congregate on their orbs. 2. Males compete for hub position proximal to the female, with the largest male assuming hub status. Smaller males move about the periphery of the orb. 3. Hub males gained the advantage of almost exclusive mating, and a potential advantage of feeding on prey captured by the female. Peripheral males pursued various alternatives, but rarely mated. 4. Females, the larger sex, occasionally preyed on males. The cost to males from female predation was no greater for hub than peripheral males. © 1979 Springer-Verlag.