Obligate, but not facultative, satellite males prefer the same male sexual signal characteristics as females

Abstract

Signalling is energetically expensive and increases the risk of predation and parasite infection. To balance the costs and benefits of mate attraction, individuals may adopt an alternative mating strategy such as satellite behaviour, in which nonsignalling males will settle near signalling males and attempt to intercept approaching females. While many suggest that alternative strategies are ‘making the best of a bad job’, little research has examined whether satellites, particularly obligate satellites, have the potential to increase their mating success by preferentially targeting more attractive signallers. Using the Pacific field cricket, Teleogryllus oceanicus, we tested the hypothesis that males are more likely to act as satellites to signalling males with particularly attractive songs, as these callers are likely to attract the most females. In this species, a novel male wing mutation, ‘flatwing’, renders some males unable to call. Flatwings are obligate satellites, while nonmutated, normal-wing males switch between calling and satellite strategies. We presented males with calling song models varying in the percentage of long-to-short chirps, a characteristic important in female choice. As was shown for females in previous work, flatwings exhibited a strong preference for calling songs composed of 60% long chirp. Normal wing males did not prefer any particular calling song model. Our results lead to the paradoxical conclusion that males with highly attractive songs may not have the highest mating success. Such male preference for male sexual signals may oppose selection by females and increase competition between signalling and satellite males. This could potentially slow the rate of male trait evolution and influence the evolution of male competition.