Female preferences for male calling bout duration in a field cricket

The calls of male field crickets attract sexually receptive females. In Gryllus integer, males differ from one another in their durations of uninterrupted calling (calling bout lengths). Tape recordings of the calls of 50 wild-caught males revealed that 14 males spent most of their calling time in short bouts (Fig. 1A), 18 in both short and long bouts (Fig. 1B), and 18 in long bouts (Fig. 1C). Re-recordings of 32 males after 3 weeks showed that calling bout lengths of individual males are stable with time (age) (Fig. 2). Three phonotaxis experiments investigated whether calling bout lengths of males affect female preferences. They demonstrated that (1) females can discriminate among conspecific males on the basis of calls alone; (2) females are preferentially attracted to males with long calling bout lengths; and (3) calling bout length is the specific factor responsible for preferential attraction. These results precisely identify a criterion that females use to discriminate among potential mates of their own species.