Chronic water restriction triggers sex-specific oxidative stress and telomere shortening in lizards

International audienceAnimals use a variety of strategies to avoid acute dehydration and death. Yet, how chronic exposure to sub-lethal dehydration may entail physiological and fitness costs remains elusive. In this study, we experimentally tested if water restriction causes increased oxidative stress (OS) and telomere length (TL) shortening, two well-described mediators of environment–fitness relationships. We exposed 100 yearling female and male common lizards (Zootoca vivipara) either to a 51-day period ofwater restriction or towater ad libitum, followed by 45 days in common garden outdoor conditions. We measured the kinetic changes in OS and TL and found that water restricted males enhanced antioxidant defences and decreased oxidative damage at day 36, whereas females did not immediately respond.Amonth and half afterwater restriction, both sexes experienced a drop in antioxidant capacity but onlymales exhibited significant TL shortening. In the following 3 years, we found that lizards with longer initial TL and those who maintained stronger antioxidant defences experienced higher longevity, irrespective of sex and water restriction. Together, these results unravelled sex-specific responses to water restriction, with potential applications in better understanding the physiological costs of increasing summer droughts as a result of global climate change