Fig. 3. Male mating attempts toward singing and mute females in small laboratory populations. (a) Average numbers of mating attempts directed toward singing and mute
females in relation to singing females per group at a particular female age (background stridulation). Error bars: SEM. Analysis by GEE revealed that actively stridulating
females attracted more mating attempts than silent females and also the total number of stridulating females in the observation cage had a significant influence on the
average frequency of male mating attempts. At female ages where relatively high background stridulation occurred, the difference in mating attempts between singing and
silent females became even more pronounced. (b) Average numbers of mating attempts received by individual females. Females received significantlymore mating attempts
during observation periods in which they stridulated than during periods when they remained mute. Error bars: SEM