Fig. 2. Effect of isolation from females on male Chorthippus biguttulus reproductive readiness. (a) The proportion of males that specifically reacted to the female song increased
with increasing duration of isolation. From the third day on, the proportions of males that stridulated only and those that in addition turned to the sound source and
approached it, remained approximately the same. (b) Average scores of responses of 14 males. Responses were scored as follows: no reaction = 0; stridulation only = 1;
stridulation and turning to the sound source = 2; stridulation, turning and approaching the sound source = 3. (^)Median of ranks; boxes include upper and lower quartile of
values; whiskers include all values. (*) Significant with p < 0.05.