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Multiple Roles of Tail Display by the Curly-Tailed Lizard Leiocephalus carinatus: Pursuit Deterrent and Deflective Roles of a Social Signal


William E. Cooper Department of Biology, Indiana University-Purdue University at Fort Wayne, Fort Wayne, IN 46805, USA. E-mail:


The same display may be used in different contexts to convey different messages, or may have other, non-signaling functions. Several lines of evidence suggest that vertical tail curling, a previously documented social display in the lizard Leiocephalus carinatus, has antipredatory functions that may include pursuit deterrence and deflection of attacks from the body to the tail, which can be autotomized. An antipredatory role of tail curling is suggested by its more frequent occurrence when a predator is approaching than moving away, its greater frequency and intensity when a lizard is approached by a predator than when it moves spontaneously, and its greater frequency when the predator approaches directly rather than on a path bypassing the lizard. Evidence is presented contradicting use of tail curling for flash concealment or as an alarm signal to conspecifics. A pursuit-deterrent function of tail curling is suggested by its (1) more frequent use by lizards close to a refuge than those further from a refuge, (2) greater frequency during direct approaches by predators, and (3) much greater frequency when a predator is far enough away for pursuit to be deterred than when the predator is close enough to pose a high risk of capture. Lizards fled into a refuge without tail curling when the predator was very close, but often stopped outside a refuge while displaying the curled tail when the predator was farther away. Tail curling also may deflect attacks to the autotomizable tail, as suggested by its occurrence during spontaneous movements when no predator is approaching and by the high frequency of completely uncurled tails among individuals under bushes. The role of the tail in autotomy may facilitate evolution of pursuit-deterrent signals involving the tail.