Interactions between thermoregulatory behavior and physiological acclimatization in a wild lizard population

Area of Science:

• Zoology
• Physiological Ecology
• Climate Change Biology

Background:

• Thermoregulation and plasticity are key climate change responses, but their interaction is poorly understood.
• Studying these mechanisms independently limits our knowledge of physiological variation in natural populations.

Purpose of the Study:

• To investigate the interaction between behavioral thermoregulation and thermal acclimatization in the lizard Sceloporus torquatus.
• To assess how these mechanisms shape physiological phenotypes like cold tolerance (Ct_min), heat tolerance (Ct_max), and preferred body temperature (T_pref).

Main Methods:

• Monthly monitoring of thermoregulatory effectiveness and physiological parameters over one year.
• Assessing population mean changes in Ct_min, Ct_max, and T_pref to infer thermal acclimatization.
• Analyzing the relationship between behavioral thermoregulation and physiological limits.

Main Results:

• Sceloporus torquatus actively thermoregulates year-round, maintaining stable body temperatures despite seasonal shifts.
• Ct_min exhibited plasticity, shifting with nighttime temperatures, while Ct_max showed less acclimatization.
• Preferred body temperature (T_pref) tracked seasonal temperature changes, enhancing thermoregulatory effectiveness.

Conclusions:

• Behavioral thermoregulation and physiological plasticity interact, influencing organismal responses to climate change.
• Thermoregulation is more effective at buffering against heat extremes than cold extremes.
• The interplay between behavior and plasticity is crucial for predicting species' resilience to rising global temperatures.