Thermoregulation
Many reptiles (including Jacky dragons) bask in the sun to raise body temperatures to a level that is required for their normal activity. Variation in perch selection occurs in related species at different times of the day. This may manifest in varying the height at which they bask or choosing different substrates (higher during the middle of the day to escape the heat from in the air just above the ground). Posture also affects energy received from the sun:
- Changing the angle of incidence can influence the level of heat absorption.
- Adjusting the surface area of the body by flattening themselves
Posture changes can also affect heat loss.
Alternate between shade and sunlight, or shuttling, is common in smaller lizards because of their rapid heating and cooling rates. Body temperatures also affect locomotor functioning and several species have mechanisms that compensate for reduced ability to respond quickly to environmental stimuli (e.g., greater approach distances when body temperature is low).