Thermal niches and activity periods in syntopic Phymaturus and Liolaemus lizards from the Andes, Argentina

LASPIUR, ALEJANDRO; MEDINA, MARLIN; AUSAS, SOLEDAD; ACOSTA, JUAN CARLOS; JOHN KRENZ; IBARGÜENGOYTÍA, NORA RUTH

ANAIS DA ACADEMIA BRASILEIRA DE CIENCIAS.

ACAD BRASILEIRA DE CIENCIAS

Lugar: Rio de Janeiro; Año: 2020

0001-3765

We compared the thermal biology of three species of the family Liolaemidae: Phymaturus williamsi, P. aguanegra and Liolaemus parvus, the latter in syntopy with each of the Phymaturus species in the highlands of the Andes, San Juan, Argentina. We predicted that, under similar harsh environments, Phymaturus species are conservative in their thermal biology, while syntopic populations of Liolaemus parvus would exhibit plasticity in thermal behavior and efficiency in thermoregulation. We determined the operative temperatures (Te), field body temperatures (Tb), preferred body temperatures (Tpref), effectiveness of thermoregulation (E), and we also recorded their activity patterns. Phymaturus species were conservative in Tb, while L. parvus populations showed wide intraspecific variation in Tb and E, suggesting greater thermal flexibility and ecotypic variation. The activity patterns of P. williamsi and L. parvus from Quebrada Vallecito were longer in duration than those shown by P. aguanegra and L. parvus from Paso Agua Negra. Specifically, while P. williamsi exhibit a bimodal pattern of activity probably to avoid exposure to high temperatures, L. parvus were active during the warmer hours. Accordingly, Phymaturus species tend to be effective thermoregulators whereas L. parvus populations behave as good thermoregulators or thermoconformers depending on the thermal condition in highly fluctuating habitats.