Estimating potential reproductive costs in the survival of a xenosaurid lizard

Abstract

Both females and males may suffer from increased mortality risk as a result of the activities and physiological processes associated with reproduction. In this study I estimated sex-specific reproductive costs in the survival rates of a viviparous and territorial lizard (Xenosaurus grandis grandis), accounting for the potential effects of population density, population growth rate and the size of individuals. I used a multi-model inference framework to test the following hypotheses: 1) female survival rate should decrease when they experience the late phases of embryo development and immediately after births take place; and 2) male survival rate should decrease when they search and compete for potential mates. Capture-mark-recapture data supported the first hypothesis but not the second. Female survival appeared to decrease right before and after parturition events. In contrast, male survival did not decrease during the mating season. I discuss the potential causes and implications of this sex-specific trade-off between reproduction and survival.