Multimodal Signaling in frogs Staurois guttatus (Ranidae): An Alerting Function of Calling
A study of Grafe and Wanger (2007) have documented the multimodal communication in Staurois guttatus (Ranidae), whereby individuals use several sensory modalities for information transfer, which is common in a wide variety of taxa. For example, humans use articulatory visual gestures accompanying speech.
Although in most anurans acoustic signals play a dominant role in intraspecific communication, the important role of visual displays has become more apparent recently. Visual displays are usually produced in concert with acoustic signals and are often very elaborate and diverse.
Frogs of the genus Staurois are known to perform both visual and acoustic displays with foot-flagging being the most stunning visual display.
Grafe and Wanger found that both male and female S. guttatus showed a large repertoire of visual displays, that are temporally linked to advertisement calling. Males showed foot-flagging, foot-raising, leg-drumming, arm-waving, vocal-sac pumping, upright posture, and open-mouth displays. Some displays were shown during both daytime and night-time, whereas other displays were only observed and videotaped during either daytime or night-time.
The results of this study show that males of S. guttatus use both acoustic and visual signals throughout most of the day and that the advertisement calls and foot-flags form a multicomponent and multimodal display. The advertisement calls are used to direct the receiver’s attention to the location of the subsequent visual signal. It is advertisement calls have an alerting function.
Photo: ©Jeet Sukumaran | Staurois guttatus in Gading, Sarawak, Borneo, Malaysia
Bottom image from: Grafe, T. U. and Wanger, T. C. (2007), Multimodal Signaling in Male and Female Foot-Flagging Frogs Staurois guttatus (Ranidae): An Alerting Function of Calling. Ethology, 113: 772–781.