Raw data for: Plastic responses of males and females interact to determine mating behaviour

Individuals can respond plastically to variation in their social
environment. However, each sex may respond to different cues and
contrasting aspects of competition. Theory suggests that the plastic
phenotype expressed by one sex can influence evolutionary dynamics in the
other, and that plasticity simultaneously expressed by both sexes can
exert sex-specific effects on fitness. However, data are needed to test
this theory base. Here, we examined whether the simultaneous expression of
adaptive plasticity by both sexes of Drosophila melanogaster fruit flies
in response to their respective social environments interacts to determine
the value of key reproductive traits (mating latency, duration and
fecundity). To vary social environments, males were kept alone, or with
same sex rivals, and females were kept alone, in same-sex, or mixed-sex
groups. Matings were then conducted between individuals from all of these
5 social treatments in all combinations, and the resulting reproductive
traits measured in both ‘choice’ and ‘no choice’ assays. Mating latency
was determined by an interaction between the plastic responses of both
sexes to their social environments. Interestingly, the mating latency
response occurred in opposing directions in the different assays. In
females exposed to same-sex social treatments, mating latency was more
rapid with rival treatment males in the choice assays, but slower with
those same males in no choice assays. In contrast, mating duration was
determined purely by responses of males to their social environments, and
fecundity purely by responses of females. Collectively, the results show
that plastic responses represent an important and novel facet of sexual
interactions.