Data from: A chorus of color: hierarchical and graded information content of rapid color change signals in chameleons

Animals rely on information-rich signals to minimize costs associated with
competition. If fighting ability is linked to stable individual attributes
(e.g. morphology), the signals that communicate information about such
ability should be relatively static. Conversely, the temporal variability
of motivation should favor dynamic threat signals that indicate an
animal's likelihood of escalating a contest. Though static colors are
used by many animals to signal quality or fighting ability, the function
of dynamic color change as a social signal has only recently begun to be
investigated. Here, we examined the information content of rapid
physiological color changes displayed by adult male veiled chameleons
Chamaeleo calyptratus during agonistic interactions by conducting
experimental trials between live chameleons and standardized,
experimentally-controlled robochameleon models. Chameleons reliably
communicated motivation with dynamic color displays – individuals that
brightened were 14 times more likely to approach the robochameleon than
non-brightening individuals. Additionally, chameleons with shorter
latencies to maximum stripe brightness had stronger bites, and those
displaying brighter, yellower stripes exhibited more aggression. The
parallels between dynamic color changes and the vocalizations used to
mediate aggressive interactions in other taxa are numerous. The use of
particular vocalizations/color changes can signal motivation levels while
specific signal elements (e.g. pitch, timing, brightness) may be linked to
fighting ability. Because the complexity and potential information content
of color signals increases markedly when organisms can display
context-specific variation in the expression of these ornaments, the study
of dynamic color signals is a field ripe for the investigation of complex
visual and signaling strategies.