Messages conveyed by assorted facets of the dewlap, in both sexes of Anolis sagrei
Faculty of Sciences. Biology
Behavioral ecology and sociobiology. - Berlin
, p. 1251-1264
University of Antwerp
Dewlaps of Anolis lizards are complex multicomponent signaling devices that have been intensively studied. Yet, the functions and multiple messages conveyed by the dewlap remain largely unknown. Here, we assess some aspects of sexual identity, individual quality, and social status that may be signaled by the dewlap in both sexes of Anolis sagrei. In addition, we investigate whether diverse facets of dewlap signaling provide additive information (redundant message hypothesis) or highlight different characteristics of the sender (multiple-message hypothesis). To do so, components of dewlap design (area, color, and pattern ratio) and use (dewlap extension frequency during intersexual context) were quantified and investigated for relationships with sexual identity (sex), individual quality (performance and health state measurements), and social status (mirror-motivated aggression). First, we found that body size together with relative dewlap area and color act as redundant messages in the advertisement of sexual identity. Second, we found that dewlap coloration in the center and edge region signals aspects of individual quality, specifically health state, but only in males. The dewlap center and edge acts primarily as redundant signals, at least for body condition and immune response. However, different color components irrespective of dewlap region convey nonredundant information about aspects of health state in males, supporting the multiple-message hypothesis. Surprisingly, dewlap use in A. sagrei males conveyed no information about the tested quality measurements nor about mirror-motivated aggression. Neither dewlap design nor use in females was related to any of these parameters. In contrast to males, correlations between components of dewlap design and use during intersexual interactions were found for females, suggesting important signaling functions of the female dewlap in a courtship context.