Área de vida, organização social e comunicação visual de Tropidurus do grupo semitaeniatus (Squamata:Tropiduridae)

Abstract

In this thesis, composed by four chapters, we addressed ecological and behavioral aspects of an endemic lizard group from Caatinga, theTropidurus of group semitaeniatus. Specifically, we investigated the patterns of space use, the structure of the social systems, as well as the process of visual communication in three species: T. helenae, T. jaguaribanus e T. pinima.In the first chapter, we analyzed the historical path of studies on home range of lizards in South America. We observed that the studies on home range of South American lizards are scarce and that accumulated information up to now is both phylogenetically and geographically restricted, with the majority of studies focusing on species of Iguania lineage and have been carried out in northwestern Argentina and southeastern Brazil. Based on this scenario of limited information, we provided a basic guideline to improve data gathering and analysis for future studies on home range of lizards. In the second chapter, we searched for patterns of space use in saxicolous lizards investigating the home range size of the three target-species. We did not found relationship between the home range size and the snout-vent length in any species. The home range size also did not differ between the sexes nor between the studied species. These results suggest that despite distinct social roles of males and females, and the interespecific dissimilarities in morphology, the inherent contingencies of saxicolity are preponderant to the patterns of spatial usage in species highly specialized in rocky environments. In the third chapter, we evaluated the social organization of the lizards Tropidurus of the semitaeniatus group analyzing the arrangement and overlaping of home range areas of the three abovementioned species. We found there was not significant difference in the average percentage of home range overlaps between intra and intersexual spatial associations in none of the species. Furthermore, the number of females spatially associated to males was not related to the home range size and body size of the males. These results reinforce the hypothesis that Tropidurus species of the semitaeniatus group did not constitute territorial species and, actually, are organized in dominancy hierarchies. In the fourth chapter, we provide by the first time information on visual communication of three species of the genus Tropidurus characterizing and comparing the structure of their visual displays. We diagnosticated two main types of visual displays, of assertion and of challenge. The assertion displays had a singular pattern in each species, while the challenge displays were relatively more conserved interspecifically, suggesting a possible phylogenetic effect along the evolution of this kind of visual display