Behaviour 2019
Differential use of unimodal signals within multimodal courtship signals of a wolf spider, Schizocosa ocreata
Brent Stoffer1, David L Clark2, Lallo Madeline3, George W Uetz1. 1University of Cincinnati, Cincinnati, OH, United States; 2Alma College, Alma, MI, United States; 3Husson College, Bangor, ME, United States

Few study organisms offer the ability to examine whether each sex might differentially use individual signal modalities within a multimodal signal. Such studies might shed light on differential selection pressures on the sexes. Male brush-legged wolf spiders, Schizocosa ocreata, use multimodal courtship signals, consisting of vibratory and visual displays. Male S. ocreata court in response to female chemical cues, but will also court in response to male competitors in attempts to intercept mating opportunities. Using video and vibratory playback techniques, we investigated the relative importance of vibratory and visual signals for both males (eavesdropping context) and females (mate preference context). Both males and females respond appropriately to each modality played in isolation. Female S. ocreata clearly prefer multimodal signals, while male S. ocreata court more in response to unimodal vibratory signals. Both sexes, however, demonstrate an ability to learn in each modality. The innate differences in the weight of unimodal signals suggest different selection pressures on the relative importance of signal modalities or on the sensory systems of each sex.