Thermal biology of Liolaemus occipitalis (Squamata, Tropiduridae) in the coastal sand dunes of Rio Grande do Sul, Brazil

The thermal biology of the small sand lizard, Liolaemus occipitalis, was studied in the coastal sand dunes at Quintão Beach (Palmares do Sul, Rio Grande do Sul, Brazil; 30° 24' S and 50° 17' W), between September, 1998 and August, 1999. Liolaemus occipitalis presented a mean body temperature of 30.89 °C (SD = 4.43 °C; min = 16.4 °C; max = 40.2 °C; N = 270), that varied on a daily and seasonal basis according to microhabitat thermal alterations. The substrate temperature was the main heat source for thermoregulation of L. occipitalis as in all seasons of the year it was responsible for the animals' temperature variation (82% of the collected lizards in the spring; 60% in the summer; 84% in the fall and 68% in the winter). The results indicate that L. occipitalis is a saxicolous, thigmothermic and heliothermic species that regulates its body temperature through behavioral mechanisms

Hatching and emergence patterns in the yellow-spotted river turtle, podocnemis unifilis (Testudines: Podocnemididae), in the várzea floodplains of the lower amazon river in santarém, Brazil

In reptiles, the hatching and emergence of a single clutch may be synchronized or may take place over a number of days, weeks, or even months, depending primarily on the microenvironment of the nest. The present study focused on the patterns of hatching and emergence of Podocnemis unifilis hatchlings in an area of várzea floodplain on the lower Amazon River in Santarém, in the Brazilian state of Pará, in 2007 and 2009. Two groups of nests were monitored for hatching and emergence, with the nests in one group being undisturbed during the entire study period. The difference between the oviposition-hatching and oviposition-emergence intervals was determined based on the monitoring of these processes in the monitored clutches. Hatchlings took 1.5 d to leave the eggshell and the eggs at the top of the nest hatched first. The size of the clutch influenced the length of the interval between the first and last hatching. Most hatchlings emerged from a nest during a single night. Hatchlings in late nests and those closer to vegetation took significantly longer to emerge. The hatching-emergence interval was greater in 2007 (11.0 d) than in 2009 (7.3 d). This study contributes to the understanding of hatching and emergence patterns in P. unifilis and the physical and environmental factors that influence them, including the variation between reproductive seasons. © 2013 Chelonian Research Foundation