Using Video Playback to Study Sexual Communication
Many sexually-selected phenotypes involve some form of visual communication. Video-playback techniques are a powerful new tool for studying visual signaling systems. Individual aspects of complex stimuli can be reliably manipulated, and stimuli can be repeatedly presented without appreciable variation in their properties. Experimenters can also construct signals which are biologically impossible, but which can be used to ask critical questions about how stimuli are perceived. Video-playback studies of sexual selection are reviewed in the context of how the methodology can be used to extend the range of questions addressed by conventional techniques. Four major issues are discussed with consideration for future studies: (1) the background against which a stimulus is presented; (2) the illumination of the stimulus; (3) the problem of pseudoreplication; and (4) experimental design considerations, including controlling for side biases and order effects and selecting appropriate response assays. Using synthetic animations may address many of these concerns.