How seasonality influences the thermal biology of lizards with different thermoregulatory strategies: a meta‐analysis

• Published in: Biological reviews of the Cambridge Philosophical Society 2024-04, Vol.99 (2), p.409-429
• Main Authors: Giacometti, Danilo, Palaoro, Alexandre V., Leal, Laura C., Barros, Fábio C.
• Format: Article
• Language: English
• Subjects: Animals; basking; Biology; Body size; Body Temperature; Body Temperature Regulation; Climate change; Climatic conditions; climatic variability; Ecological effects; Ecological research; ectotherm; Habitats; Humans; Lizards; Lizards - physiology; Meta-analysis; Niches; Phylogeny; reptiles; Seasonal variations; Solar radiation; Species; Squamata; synthesis; Temperature; Temperature gradients; Temporal variations; thermal ecology; Thermoregulation; Thermoregulatory behavior
• ISSN: 1464-7931; 1469-185X
• DOI: 10.1111/brv.13028

ABSTRACT Ectotherms that maintain thermal balance in the face of varying climates should be able to colonise a wide range of habitats. In lizards, thermoregulation usually appears as a variety of behaviours that buffer external influences over physiology. Basking species rely on solar radiation to raise body temperatures and usually show high thermoregulatory precision. By contrast, species that do not bask are often constrained by climatic conditions in their habitats, thus having lower thermoregulatory precision. While much focus has been given to the effects of mean habitat temperatures, relatively less is known about how seasonality affects the thermal biology of lizards on a macroecological scale. Considering the current climate crisis, assessing how lizards cope with temporal variations in environmental temperature is essential to understand better how these organisms will fare under climate change. Activity body temperatures (Tb) represent the internal temperature of an animal measured in nature during its active period (i.e. realised thermal niche), and preferred body temperatures (Tpref) are those selected by an animal in a laboratory thermal gradient that lacks thermoregulatory costs (i.e. fundamental thermal niche). Both traits form the bulk of thermal ecology research and are often studied in the context of seasonality. In this study, we used a meta‐analysis to test how environmental temperature seasonality influences the seasonal variation in the Tb and Tpref of lizards that differ in thermoregulatory strategy (basking versus non‐basking). Based on 333 effect sizes from 137 species, we found that Tb varied over a greater magnitude than Tpref across seasons. Variations in Tb were not influenced by environmental temperature seasonality; however, body size and thermoregulatory strategy mediated Tb responses. Specifically, larger species were subjected to greater seasonal variations in Tb, and basking species endured greater seasonal variations in Tb compared to non‐basking species. On the other hand, the seasonal variation in Tpref increased with environmental temperature seasonality regardless of body size. Thermoregulatory strategy also influenced Tpref, suggesting that behaviour has an important role in mediating Tpref responses to seasonal variations in the thermal landscape. After controlling for phylogenetic effects, we showed that Tb and Tpref varied significantly across lizard families. Taken together, our results support the notion that