Range structure, microhabitat use, and activity patterns of the saxicolous lizard Tropidurus torquatus (Tropiduridae) on a rock outcrop in Minas Gerais, Brazil

Although Tropidurus is a widely distributed lizard genus in South America and the Galapagos Islands, studies on space use and spatial distribution are scarce. We studied the home range structure of the saxicolous lizard Tropidurus torquatus based on the inland population of a rock outcrop in Minas Gerais State, southeastern Brazil. Lizards were individually marked and observed during reproductive and non-reproductive seasons. Using the mínimum convex polygon method, we found that average total range size of males during the reproductive season was larger than that of females, and that both had similar total range sizes in the non-reproductive season. The harmonic mean method showed that males have a larger home range size than that of females during both seasons. As expected for a polygynous species, the average number of males whose total ranges overlapped those of females tended to be higher in the reproductive season than in the non-reproductive season. Intrasexually, the number of females whose total ranges were associated with those of other females was also higher in the reproductive season than in the non-reproductive season. For males, this number remained low in both seasons, suggesting that males use more exclusive areas, whereas the smaller total ranges of females apparently sustain a higher density of individual s during the reproductive season. Frequency of microhabitat use in relation to vegetation increased in the non-reproductive season and the activity patterns of lizards shifted from bimodal in the reproductive season (rainy period) to unimodal in the non-reproductive season (dry period). Thus, the range structure, microhabitat use, and activity patterns of the T. torquatus observed here were all influenced by the time frame affecting their spatial ecology.