Colorful tails that become cryptic during ontogeny are found in diverse taxa. Nevertheless, the evolutionary bases for this change remain debated. Recent work suggests that colorful tails, deflective displays, and striped patterns may represent antipredator mechanisms used by immature lizards to compensate for being more active and hence more vulnerable to predation (increased movement hypothesis, IMH). I challenged the generality of IMH by comparing foraging behavior and frequency of tail displays across five Acanthodactylus lizards that vary in fundamental life history traits, before and after the tail changed color. As these species underwent changes in tail coloration, they congruently adopted less risky behaviors and reduced the frequencies of tail displays. Contrary to expectation, in two species, the hatchling risky behavior resulted not from increased movements but from longer stay in exposed microhabitats. I suggest that colorful tails and deflective tail displays are synergistic antipredator mechanisms neonates use to minimize the fitness consequences of using various risky behaviors rather than increased movement alone.
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Acknowledgments I would like to thank Bill Cooper, Raymond Huey, Kathy Hughes, Tracy Langkilde, Oswald Schmitz, David Skelly, Gregory Watkins-Colwell, and two anonymous reviewers for their helpful comments on this paper and to Ross Alford for his valuable statistical advices. This work was supported by the Gaylord Donnelley Environmental Fellowship, Yale Institute for Biospheric Studies (YIBS), and by the Israel Nature and Parks Authority.
- Deflective display
- Dorsal pigmentation
- Predation risk
- Tail autotomy