Phenotypic diversification and reproductive effort in snakes and lizards of South America

CARDOZO, G; CHIARAVIGLIO, M

Genova

Congreso; X Congressso Nazionale della Societas Herpetologica Italica; 2014

From an evolutionary perspective, the organism?s phenotype is considered a causal link to its reproductive output. Moreover, from a biological conservation perspective, variability in reproductive strategies is important because environmental changes might influence them enhancing the vulnerability of the species. The aim of our research project is to evaluate variations in reproductive strategies in natural populations of South American snakes and lizards from an evolutionary and ecological perspective. We present the results obtained for two study models: a large viviparous snake, Boa constrictor occidentalis, and two closely related large lizards, Tupinambis meriane and Tupinambis rufescens. Our main study area is the biogeographic region of Gran Chaco Sudamericano, central Argentina. In B.constrictor occidentalis we found interpopulation variations in reproductive traits, evidencing phenotypic plasticity. Moreover, we show that forest loss could enhance vulnerability to extirpation through constraints placed on reproduction. In T. merianae and T. rufescens we found that reproductive strategies are flexible, showing spatial variations according to social contexts. Females presented great continuous variability in body shape, suggesting the existence of trait polymorphism as a result of the co-existence of diverse reproductive strategies. Mating strategies shaped by evolutionary forces are frequently associated with phenotypic diversification