Thermal Ecology and Physiology of Ectothermic Reptiles

Ectothermic reptiles depend on environmental heat sources to regulate their body temperature, a process that underpins their metabolism, growth, reproduction and survival. Behavioural strategies—such as basking, microhabitat selection and postural adjustments—interact with physiological mechanisms, including peripheral blood‐flow modulation and metabolic rate adjustments, to maintain body temperatures within species‐specific performance curves. Thermal physiology in reptiles spans from embryonic development in nests to adult thermoregulatory behaviour in the field, encompassing trade‐offs between optimal temperature selection and risks of dehydration or predation. Phenotypic plasticity and evolutionary adaptations, such as shifts in preferred temperature or transitions from egg‐laying to live‐bearing reproduction, modulate species’ responses to climatic gradients. Mechanistic niche models and dynamic energy budget theory increasingly inform projections of activity windows, water loss and energy expenditure under future climates. Given the global distribution of reptiles and their sensitivity to temperature change, advances in thermal ecology are critical for forecasting range shifts, assessing vulnerability and guiding conservation interventions, from habitat design to assisted translocations. Interdisciplinary approaches now integrate field experiments, biophysical modelling and macroevolutionary analyses to reveal how thermal environments shape phenotypic diversity and ecological resilience in reptilian lineages.

Research from Nature Portfolio

Recent work has shown that the evolution of live‐bearing reproduction in temperate lizards facilitates colonisation of cooler habitats by allowing embryos to develop at stable thermal conditions inside the mother. Comparative analyses within a diverse genus revealed that species with live birth evolve larger optimal body sizes, driven indirectly by shifts into colder environments. This macroevolutionary signature indicates that viviparity unlocks ecological opportunities otherwise inaccessible to egg‐laying relatives, reconfiguring patterns of body size diversity without necessarily accelerating the rate of size evolution. By linking reproductive mode, thermal environment and phenotypic outcomes, this study highlights how life‐history shifts can govern long‐term responses to climatic gradients.

Thermal Ecology and Physiology of Ectothermic Reptiles publication trend

The graph below shows the total number of articles in thermal ecology and physiology of ectothermic reptiles across all publications each year (not limited to Nature Index journals).

Technical terms

Ectotherm: An organism that relies primarily on external heat sources to regulate body temperature rather than internal metabolic heat.

Thermoregulation: Behavioural and physiological processes by which an organism maintains its body temperature within optimal limits for performance.

Hydroregulation: The control of water balance in the body, involving behavioural and physiological adjustments to prevent dehydration.

Viviparity: A reproductive mode in which embryos develop inside the mother’s body and live young are born, often associated with adaptation to cooler climates.

Phenotypic plasticity: The capacity of an organism to adjust its physiology, morphology or behaviour in response to environmental variation without genetic change.

Dynamic energy budget (DEB): A theoretical framework describing how organisms allocate energy and matter for maintenance, growth, development and reproduction over their life cycle.

References

1. Viviparity imparts a macroevolutionary signature of ecological opportunity in the body size of female Liolaemus lizards. Nature Communications (2024).
2. The Semi‐Natural Climate Chambers across Latitudes: A Broadly Applicable Husbandry and Experimental System for Terrestrial Ectotherms under Climate Change. Advanced Science (2025).
3. When water interacts with temperature: Ecological and evolutionary implications of thermo‐hydroregulation in terrestrial ectotherms. Ecology and Evolution (2019).
4. NicheMapR – an R package for biophysical modelling: the ectotherm and Dynamic Energy Budget models. Ecography (2019).