Incubación de la puesta de la "iguana colorada" (Tupinambis rufescens, Sauria, Teiidae): evolución y consecuencias del peso inicial de los huevos

Abstract

Incubation of the clutch of the "red teyu" (Tupinambis rufescens, Sauria, Teiidae): evolution and effects of initial egg weight. This paper is the third of a series on the biology of T. rufescens (Gunther, 1871), a lizard from semiarid regions in Bolivia, Paraguay and Argentina. Its populations are exposed to severe hunting pressure due to the exportation of tanned leather. The evolution of non-cleidoic egg weight under artificial incubation is studied, as well as the relationships of initial egg weight versus maximum egg weight, weight at eclosion, and neonate weight. Under these experimental conditions, the incubation period was 85 days (average), and the egg mass increased about 85% (average), because of water incorporation from the environment. Factors affecting the success in artificial incubation were examined. Incubated under equal conditions, bigger eggs produce robust hatchlings, with better survival chances in captivity than smaller hatchlings, originated in smaller eggs. Potential effects of unstable seasonal pluviosity -typical of the dry Chaco- upon the population dynamics of T. rufescens were examined.