Estudos macroecológicos em canídeos: uma perspectiva neotropical

Abstract

The Macroecology is a way to study the relationships between organisms and their environment from a historical and geographical perspective. The observation of phenotypic patterns in large geographic scales has led to the establishment of rules ecogeographic, these being studied at inter and intraspecific levels. Generally canids have a high vagility, as well as great potential for colonization, these features are accompanied by numerous phenotypic variations. Within the Neotropical canids, two species stand out for its wide latitudinal distribution, Cerdocyon thous and Lycalopex culpaeus, being interesting models for macroecological studies. In this paper, we analyze the sexual size dimorphism (SSD) in the family Canidae, as well as the historical and ecological contribution to the phenotypic variation in C. thous and L. culpaeus from geometric morphometric analysis, niche models and phylogeography. From the analyses of SSD we observed that the canines do not follow the rule of Rensch. Likewise the SSD in the family does not show a Brownian evolution, not being apparently related to the phylogenetic history. The low SSD seems to be the result of the monogamous behavior of the family. The species C. thous has a disjunctive distribution, lying populations north south of the equator, separated by the Amazon basin. At south of the equator we observed a classic pattern of Bergmann, where populations at higher latitudes showed a greater body size. Being this increase in size related with lower temperatures. Meanwhile north of the equator there was an inverse pattern to the rule of Bergmann and the nearest populations to the equator considerably larger. This inverse pattern seems to be the effect of historical processes and not the result to the current environmental characteristics. From the biogeographic and phylogeographic analysis of L. culpaeus, was observed a strong genetic structuring. The genetically established populations also showed significant differences in the shape of skull and mandible. The shape of the skull appears to be related to the genetic structure and the geographic structuring of the populations. It was also determined that the variations in size of L. culpaeus were influenced by temperature and environmental seasonality, showing a classic pattern of Bergmann's rule. From our studies, we could observe general patterns of sexual dimorphism in the canids, as well we could generate biogeographic hypothesis about the differentiation among populations, quantify the ecological and historical contribution of the phenotypic variation and provide an important information for the conservation of the species C. thous and L. culpaeus.