Etograma básico, ecologia termal e dimorfismo sexual de Tropidurus itambere Rodrigues, 1987 (Squamata: Tropiduridae) em uma área de campo rupestre no sudeste do Brasil

Abstract

The aim of this study was to elaborate a basic ethogram for adult individuals of Tropidurus itambere, through observations accomplished in field and outdoor and indoor enclosures and to study the thermal ecology and the sexual dimorphism of the lizards, on December 2006 and between February and November 2007. The observations of the behaviors were accomplished by the method of the focal animal and scan, totalizing 285 hours of registrations. In the artificial enclosures the lizards were observed in five situations: (1) individual alone; (2) 1 male + 1 male; (3) 1 male + 1 female (4) 2 males + 1 female (5) 1 female + 1 female. The behaviors exhibited by the captive individuals were similar to those observed in the field. We registered 78 behavioral acts distributed in nine functional categories. The head bob was the act more frequently exhibited by the species, having been observed in all the treatments in the outdoor enclosure. The behaviors head bob and to lick the substratum seem to act together as signs of recognition of the area. The body temperature average of activity of T. itambere was 32,08 ± 3,36ºC and it presented seasonal variation accompanying the environmental temperatures. The temperatures of the microhabitats (substratum and air) influenced the body temperature of the lizards so that in the rainy season just the temperature of the air affected the temperature of the lizards and, in the dry season, just the temperature of the substratum affected the temperature of individuals. The analyses showed a significant difference in size and shape of the body and mass between the sexes, with the males being heavier and larger, presenting the measures of all the morphometrics variables significantly larger than the measures of the females, except for the width of the abdomen whose average of the females was larger than that of the males, even so that difference was not significant. The discriminant analysis selected the size of the head (RCT) as the variable that better explained the differences between the sexes, having classified correctly 89,5% of the individuals.