Trade-off between behavioral thermoregulation and hydration status in the false coral snake Oxyrhopus guibei (Serpentes, Dipsadidae)

Abstract

Most reptiles actively thermoregulate by using behavioral adjustments to achieve andmaintain their preferred body temperature. However, the pursuit of a thermal optima isaccompanied by a trade-off with potential water loss. likewise, there are a wide range of otherlife-history traits that governed behavioral thermoregulation, such as food consumption. Hence,thermoregulatory behavior should be a trade-off among all these physiological activities. Theaim of this study is to test the hypotheses that: (1) individuals of the false coral snake Oxyrhopusguibei under moderate dehydration preferred lower ambient temperature than hydrated ones infavor of water conservation, and that (2) individuals of the false coral snake O. guibei undermoderate dehydration, after feeding, exhibit a greater extent of behavioral thermoregulationthan unfed hydrated ones without paying any desiccation costs, since they can rely on dietaryand metabolic water produced. In order to accomplish this, we will use a full factorial design(2" runs) to test the effect of two factors at two levels on the preferred temperature selected bythe snakes in a thermal gradient. We expect that dehydrated snakes will select lower ambienttemperatures than hydrated ones in the thermal gradient. However, we also expect that waterconservation will be probably abandoned when dehydrated snakes are fed, allowing them tolook for higher temperatures compared to unfed dehydrated individuals. (AU)