Factors Affecting the Intra-populational Variation in Dorsal Color Pattern of an Iguanian Lizard, Oplurus cuvieri cuvieri

Abstract

Animal color patterns often have functions in thermoregulation, predation avoidance, and intraspecific communication. Examining intraspecific variation of color patterns is an effective approach to clarify their functions in a specific animal. We investigated the variation of dorsal color pattern within a dry forest population of the Madagascan iguanian lizard, Oplurus cuvieri cuvieri. Mark-and-recapture study showed that the number of dorsal black bands (DBBs) varies from one to seven, and often increases and decreases ontogenetically. Among four factors (snout-vent length, sex, age, and habitat) and three interactions between them, only sex and habitat had significant effects on the number of DBBs. Female lizards and lizards inhabiting a forested area tended to have more DBBs than males and those in an open habitat, respectively. All captive born hatchlings had seven DBBs, and juveniles reared under a 40W lamp retained more DBBs than those reared under a 60W lamp. This suggests that the number of DBBs of O. c. cuvieri is affected by thermal conditions, implying a thermoregulatory function of this color pattern.