Seismic signals are crucial for male mating success in a visual specialist jumping spider (Araneae: Salticidae)

The diversity of courtship displays throughout the animal kingdom is immense and displays can range from seemingly simple, to incredibly complex. Signallers often possess elaborate morphological adaptations for signals directed at a specific sensory modality in receivers. In some cases, these signals are so compelling to human observers, the possibility that important signals exist in other sensory modalities is ignored, potentially resulting in an incomplete characterization of the communication system. Jumping spiders (Salticidae) have remarkable visual capabilities. Yet one species, Habronattus dossenus, has recently been shown to have a complex repertoire of multicomponent seismic courtship signals in addition to and produced in concert with its multiple visual ornaments and movement displays. Here, we demonstrate the importance of these seismic signals in the courtship display of H. dossenus by comparing mating frequencies across experimentally manipulated treatments. Virgin females were paired with males from one of two experimental groups: nonmuted males or muted males. We found that females were significantly more likely to copulate with nonmuted males than with muted males. Furthermore, in all pairs that copulated, the latency to copulation was significantly shorter in nonmuted pairings than in muted pairings and precopulatory cannibalism rates were significantly lower. These results demonstrate that seismic signals are a critical component of male H. dossenus courtship displays. Additionally, we demonstrate that many other Habronattus species include a diversity of seismic signals in their courtship displays and we discuss potential selection pressures that may drive the evolution of multimodal displays even in species that already possess elaborate morphological adaptations for signals directed at one sensory modality.