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| Author(s): |
Noraly Shawen Liou
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | São Paulo. |
| Institution: | Universidade de São Paulo (USP). Instituto de Biociências (IBIOC/SB) |
| Defense date: | 2008-12-05 |
| Examining board members: |
Miguel Trefaut Urbano Rodrigues;
Marianna Botelho de Oliveira Dixo;
Vanessa Kruth Verdade
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| Advisor: | Miguel Trefaut Urbano Rodrigues |
| Abstract | |
In general, the animals have specificity for? different portions of the habitat, the microhabitat. Most of the handling of an animal in the landscape is related to the spatial-temporal distribution of its resources. The monitoring of species based on capture rate can provide data on variance of abundance in a temporal and spatial basis. In this study I describe the population structure of Enyalius iheringii and Enyalius perditus over five years of field research. I considered the sex ratio and age distribution of individuals captured in the Estação Biológica de Boracéia, and based on these parameters, I detect whether there is spatial, temporal, and seasonal variation in any of these parameters. The results indicate that males and females of Enyalius iheringii do not differ significantly in weight and snout-vent-length (SVL). Females of Enyalius perditus, however, are significantly larger and weighty than males. Males and females of both, Enyalius iheringii and E. peditus occur in equal proportions in the five transects monitored. The abundance of the two species was higher during the wet season. This result may indicate that the peak of activity of adults is a result of intense activities of foraging, mates, and oviposition. If it is true, the abundance of both species would be directly related to the increase in temperature and rainfall at the beginning of the rainy season, especially in the months of September and October to January. There was no annual differences in density or sex ratio for E. iheringii and E. perditus during the period of study. The genusEnyalius present wide distribution associated to forested habitat. Most species are found along the Atlantic Forest, but there are populations in isolated patches of semiarid Caatingas, gallery forests of the Cerrado, and E. lechii, restricted to the Amazon basin. Enyalius perditus and E. iheringii although occurring in forest fragments in southeastern Brazil where most of the major research centers in the country occur, are very poorly known in respect to natural history, home range and pattern of displacement. In this work, I describe the use of forest by Enyalius iheringii and Enyalius perditus based on the horizontal and vertical displacement of individuals, by tracking lizards using thread-bobbins (quilt cocoons or spools-and-line device). The general pattern of displacement seems not to differ between males and females of Enyalius perditus. Estimates of home range were highly variable from 10 to 517 m2 for Enyalius perditus and 88 and 154 m2 for Enyalius iheringii. There was no difference in rate of displacement between the species as well as in the distances tracked over the forest floor, above the floor, or in the preferences for different types of perches. In general, studies using sympatric lizards show that ecological segregation occurs between species, allowing their coexistency. As to diet, understand the reproductive biology of the species is important to have a clearer view of the competitive process and the environmental performance of species in areas os sympatry. In this study, I have checked for differences in diet and reproductive biology of two species of Enyalius living in allopatry and sympatry. The food niche breadth obtained for E. perditus show greater specialization when the species is found in sympatry to E. iheringii, and lower when it occurs in alopatric. The same applies to E. iheringii in sympatric and allopatric sites. Apparently, the reproductive biology for both species is related to the increase in rainfall and temperature. The development of vitellogenic follicles begin around September, at the end of spring. Apparently, the recruitment and oviposition occur in the rainy season. The hatchling of eggs probably occur during the rainy season so that juveniles can found food sources. The majority of females with vitelogenics follicles and juvenile are found between October and December. (AU) | |