Editorial: Effects of urbanization and climate change on the physiology of amphibians and reptiles

Amphibians and reptiles both experience microhabitat changes due to urban landscape shifts. In two of the research articles, we observe how such modifications alter the thermal and behavioural responses of species. Apte et al. (2025) investigated the thermal physiology of the Mysore Day gecko (Cnemaspis mysoriensis) in the major metropolitan city of Bengaluru, India. They found human-made microhabitats had slightly higher and more variable environmental temperatures than natural microhabitats, but the geckos did not exhibit significant shifts in their thermal physiology. Instead, they relied on behavioural thermoregulation to maintain body temperatures within their preferred range. This study highlights the importance of retaining natural microhabitats in urban landscapes as the temperature range of natural microhabitats closely matches the thermal range of these species. Monroe et al. (2024) examined the physiological and behavioural responses of the urban exploiter Gulf Coast Toad (Incilius nebulifer) to urbanization and climate variation. Interestingly, populations in the warmest and least urbanized sites exhibited the highest locomotor performance, suggesting that the energetic costs of living in urban areas might have a nuanced relationship with thermal tolerance of the species. Together, these two studies demonstrate how multiple stressors must be studied together to accurately predict population outcomes.Monroe et al. 2024 (discussed above) also showed that the Gulf Coast toad populations in more urbanized sites showed elevated baseline and stress-induced corticosterone release rates, faster negative feedback recovery and higher lipid storage. Climate, on the other hand, had a non-linear relationship with these traits, with populations at both thermal extremes showing reduced corticosterone and lipid levels. The rate of glucocorticoid recovery following stress increased with urbanisation but decreased with temperature, consistent with the "on-again, off-again" hypothesis of glucocorticoid regulation -whereby efficient post-stress recovery enables organisms to mount repeated stress responses without chronic physiological costs. 2025) explored the hormonal and behavioural responses of young common toads (Bufo bufo) to artificial light at night (ALAN) and noise pollution. This study is also a shift from populationlevel responses to measuring individual consistencies in phenotypic traits. They found that while corticosterone profiles changed during ontogeny, individual consistency in stress responses was low. Interestingly, foraging rates increased under both ALAN and noise pollution, but these behavioural changes were not correlated with stress hormone levels. This decoupling suggests that phenotypic plasticity, rather than individual variation in the stress axis, may enable B. bufo to tolerate urban stressors during early life.While the studies above focus basically on physiological regulation, Pradhan et al. ( 2026) examined a distinct but equally critical axis of anthropogenic threat, chemical contamination, through an investigation of heavy metal accumulation in olive ridley sea turtles (Lepidochelys olivacea) at two mass nesting rookeries in India. As long-lived, wide-ranging reptiles occupying higher trophic positions, sea turtles are particularly susceptible to bioaccumulation of heavy metals across multiple life stages. By measuring the concentrations of nine heavy metals in adults, in-utero and oviposited eggs, hatchlings, and nesting beach sand, the authors showed that contaminants move across both maternal and environmental pathways. Heavy metals in in-utero eggs provided direct evidence of maternal transfer, while correlations between sand and hatchling metal concentrations suggested environmental exposure. This multi-stage design highlights how industrial and agricultural pollution can affect sea turtles across life stages.The articles in this research topic show hepertofauna responses to urbanisation and climatic change are rarely uniform. Species differ in their responses through physiological adjustment, behavioural flexibility, or a combination of both. The Mysore Day gecko primarily relies on behavioural adjustments while maintaining relatively conserved physiology. In contrast, the Gulf Coast Toad shows population-level variation in glucocorticoid dynamics, whereas the common toad displays flexible behaviour that is largely independent of hormonal state. This diversity cautions against generalisations and reinforces the need for multi-species, multi-parameter approaches. Multiple stressors frequently co-occur and interact with thermal changes, sensory pollution, and chemical contamination; however are mostly studied individually. Life-stage dependency of responses, illustrated both by ontogenetic shifts in corticosterone profiles in common toads and by maternal contaminant transfer in olive ridley sea turtles, highlights that vulnerability assessments must span the full life cycle. Future research should prioritise the simultaneous measurement of multiple physiological traits across environmental gradients (see Figure 1). Geographically diverse datasets (tropical, subtropical, and temperate) on herpetofaunal communities are particularly needed, given that the majority of global amphibian and reptile diversity occurs in regions that are disproportionately underrepresented in physiological research. Ultimately, insights from this research topic will help guide conservation interventions that consider the complex and interacting pressures now facing herpetofauna.