Acclimation to Water Restriction Implies Different Paces for Behavioral and Physiological Responses in a Lizard Species
Abstract
Chronic changes in climate conditions may select for acclimation responses in terrestrial animals living in fluctuating environments and beneficial acclimation responses may be key to the resilience of these species to global changes. Despite evidence that climate warming induces changes in water availability, acclimation responses to water restriction are understudied relative to thermal acclimation. In addition, acclimation responses may involve different modes, paces and trade-offs between physiological and behavioral traits. Here, we tested the dynamical acclimation responses of a dry-skinned terrestrial ectotherm to a chronic water restriction. Yearling common lizards (Zootoca vivipara) were exposed to a sub-lethal water restriction during 2 months of the summer season in laboratory conditions, then released in outdoor conditions for 10 additional months. Candidate behavioral (exploration, basking, and thermal preferences) and physiological traits (metabolism at rest and standard water loss rate) potentially involved in the acclimation response were measured repeatedly during and after water restriction. We observed a sequential acclimation response in water restricted animals (yearlings spent less time basking during the first weeks of water deprivation) which was followed by delayed sex-specific physiological consequences of the water restriction during the following months (thermal depression in males and lower standard evaporative water loss rates in females). Despite short-term negative effects of water restriction on body growth, annual growth, survival and reproduction were not significantly different between water restricted and control yearlings. This demonstrates that beneficial acclimation responses to water restriction involve both short-term flexible behavioral responses and delayed changes in thermal and water biology traits.
Origin : Files produced by the author(s)
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