Patterns of throat colour variation in Quedenfeldtia trachyblepharus, a high-altitude gecko endemic to the High Atlas Mountains of Morocco

Abstract

The persistence of marked phenotypic variation within species is evolutionarily puzzling. We uncovered remarkable variation in throat colouration in a high-altitude gecko (Atlas Day Gecko, Quedenfeldtia trachyblepharus) endemic to the High Atlas Mountains of Morocco. Orange, yellow, and white variants were found in approximately equal proportions in both sexes, and in juveniles and adults. The colour variants did not differ in body size or in body condition, but there was some indication that orange males have relatively longer jaws than white or yellow males. The number of mites harboured by an individual was not a function of its sex or of its throat colouration, but larger lizards did harbour more mites. Our data do not support the hypotheses that throat colour variation is due to selection pressures differing between the sexes or through ontogeny, or signals immunocompetence, but offer some support for the hypothesis that throat colour variation signals dominance. Future investigations on the evolution of throat colour variation in this species should use spectrophotometry to obtain finer colour classification and incorporate measures of fitness.