Infection influences vibratory signal components in a wolf spider

Abstract

AbstractWhile most research on sexual signals as indicators of health status and infection has been focused on communication by visual (color), airborne acoustic (song structure, amplitude, frequency, and pattern), or chemical means, new evidence suggests that substrate‐borne vibratory signals can also be a reliable indicator of male quality and possibly infection history. In this study, we investigated the ability of the vibratory cues in multimodal sexual signals of Schizocosa ocreata wolf spiders to convey male health information to a female, and whether females adjust their mate choice decisions based on these cues. Individual components of the complete vibratory signal, including stridulatory pulse rate, mean amplitude, and peak amplitude, were all significant predictors of mating success in live trials. Males infected as a juvenile (during the penultimate molt) had significantly lower stridulatory rate and peak amplitude than control males. There were no significant differences in any of the vibratory signal components between control males and males infected as adults (1 h prior to mating trials). This suggests that the vibratory cues in this species may be altered when infection occurs during development, allowing females to avoid males that have been immunocompromised in the past. However, these cues are not reliable indicators of whether a male is actively infected, which means that the evaluation of these cues will not help a female avoid contact with infected individuals. Taken together, these results suggest that vibratory signals may convey honest information about male quality and past health, allowing females to choose mates that have not been compromised during development.