Heightened perception of competition hastens courtship

When animals use costly labile display or signal traits to display to the opposite sex, they face complex decisions regarding the degree and timing of their investment in separate instances of trait expression. Such decisions may be informed by not only the focal individual’s condition (or pool of available resources), but also aspects of the social environment, such as perceptions of same-sex competition or the quality of available mates. However, the relative importance of these factors to investment decisions remains unclear. Here we use manipulations of condition (through dietary nutrition), recent social environment (exposure to a silenced male, non-silenced male, female, or isolation), and female mating history (single- or multiple-male) to test how quickly male decorated crickets (Gryllodes sigillatus) decide to begin courting an available female. We find that males that were previously housed with non-silenced males started courting the female earlier than other males. Females only mounted males after courtship began. Our results suggest a strong effect of the perception of competition on the decision to invest resources in sexual signalling behaviour, and that females might exert directional selection on its timing.
Methods
Data collection and processing is detailed in the associated paper.