Herbivory in Liolaemus poecilochromus, a Small, Cold-Climate Lizard from the Andes of Argentina

Herbivory is generally thought to be restricted to reptiles with large body sizes that live in warm climates. We show that Liolaemus poecilochromus is primarily herbivorous (>80% plants in diet) even as juveniles, making them the smallest herbivorous reptile known. We detected relatively few differences in diet between the sexes, despite male-biased sexual dimorphism in head and body size. Adults consumed more mites and flowers than juveniles, and we detected a weak ontogenetic shift from omnivory to herbivory that is attributable to the lower volumetric consumption of plants by juvenile males. We discuss the abiotic and biotic conditions that likely selected for herbivory in this and other small-bodied, high-elevation Liolaemus.