Meeting Abstract

36.7  Monday, Jan. 5  Studying cues for species identification using robotic lizards in the field ORD, TJ*; STAMPS, JA; Harvard University / Univ. of California, Davis; Univ. of California, Davis tord@oeb.harvard.edu

Theory suggests that territorial animals should recognize and selectively respond to species-specific components of displays used in territorial defense. We examined whether the territorial lizard, Anolis gundlachi, discriminate and respond differentially to conspecific versus novel territorial signals using robotic lizards to playback different displays to free-living lizards on Puerto Rico. The displays of A. gundlachi consist of stereotyped headbobs which are sometimes accompanied by the extension of a distinctly colored dewlap. The extent to which these lizards rely on headbob patterns, the dewlap, or both for species recognition is largely unknown. In our first set of playbacks, lizards were presented with a robot that extended the conspecific colored dewlap while performing either a conspecific or a novel display. In the second set of playbacks, the same conspecific or novel displays were presented, but the dewlap was not extended. When the display included the dewlap, lizards were equally aggressive and responded quickly to both the conspecific and novel display. When the dewlap was not extended, the level of aggression was again similar for both displays, but lizards took longer to respond to the novel headbob than to the conspecific headbob. This shows lizards are able to discriminate species using the headbob. The role of the dewlap is less clear. The dewlap may either provide species cues that override those conveyed by the headbob or function as an evocative threat signal irrespective of the headbob pattern that accompanies it. In either case, lizards responded equally aggressively to the conspecific and non-conspecific displays. A review of the literature suggests other animals are also less discriminatory of species-specific signals than predicted by theory.