Explorando informações multicaráter da ecologia do tracajá (podocnemis unifilis troschel, 1848): a história de vida contada através dos ninhos

Abstract

When one observes the life history of any organism, besides the physiological, behavioral and morphological adaptations modified over time, there are also individual adjustments in response to environmental changes, and ecological interactions in the environment. This doctoral thesis documents important information on the life history of the Yellow-Spotted Amazon River Turtle (Podocnemis unifilis), describing some aspects of biology focusing on the nests associated to different incubation substrates, and the consequences of a generalist nesting on the success of the offspring, sex ratio and possible interspecific interactions. How the investment of females was different for each type of substrate, potentially different was the life history of nests incubated under different environmental conditions (i.e., clutch size, time of incubation, eclosion success and success incubation, and hatchlings size). As the heat retention generally shown distinct between the incubation substrates the incidence of females was higher than that of males in the sandy substrate. Even with a global trend of feminization the hatchlings of turtles temperature dependent sex, the sex ratio was balanced, since the incidence of males was higher in the clayey substrates. For remaining in specific areas throughout the development of the embryos nests are susceptible, and under the influence of various biotic and abiotic factors in the incubation period of the eggs, this being the most vulnerable and critical part of the life cycle of the species. Multiple interactions between consumers and their resources make it possible the occurrence of different relationships among species, and the competitive suppression among ants Nylanderia sp.1 and Solenopsis geminata, generated a positive effect on the hatching success of P. unifilis. As they are a group with hierarchical competitive system, ants usually do not share resources, and how different forms of interactions can occur simultaneously, the competitive suppression between them generated a positive effect on a hatching rate of the P. unifilis, through facilitation. The Yellow-Spotted Amazon River Turtle is the species of resident turtles more general in the basins where it occurs. These differences found in life history may be partly reflective of a plastic response also associated with the use of different habitats of nesting, which would result in increased resilience of populations P. unifilis extreme climatic events and associations with other organisms. An approach centering on nests will bring new perspectives to knowledge about biology, ecology and vulnerability of turtles in the face of environmental change in progress in the Amazon.