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.
Percent of plant volume in the stomachs of Liolaemus poecilochromus (n = 60) from Salar del Hombre Muerto, Catamarca, Argentina as a function of their body size (snout–vent length). The positive statistical trend based on transformed data (r2 = 0.098, P = 0.015; see text) suggests that L. poecilochromus exhibit an ontogenetic shift in diet, as shown for other species of small herbivorous lizards. However, the weakness of this correlation indicates poor explanatory power and uncertainty regarding its biological significance (see text).
Percent of plant volume in the stomachs of Liolaemus poecilochromus from Salar del Hombre Muerto, Catamarca, Argentina by sex and age class. Sample sizes: juvenile females (n = 13), juvenile males (n = 15), adult females (n = 20), and adult males (n = 12). An ANCOVA of the transformed data revealed a significant interaction between sex and age class (F1,55 = 3.537, P = 0.020), with juvenile males eating relatively less plant matter than the other sex and age classes. Adults: black squares; juveniles: white circles. Error bars are ±SE.
Contributor Notes
Associate Editor: J. D. Litzgus.