Thermoregulatory behavior varies with altitude and season in the sceloporine Mesquite lizard.

In ectothermic vertebrates, body temperature is the factor that most affects physiology and behavior. Most ectotherms show limited physiological control of body temperature, so they use behavioral strategies to regulate and maintain a constant temperature within a range. The variation of environmental temperature due to altitude and seasonality could have a great impact on the regulation of body temperature in lizards, even more so in elevation gradients, in which environmental temperature decreases with elevation.

We chose three populations of the lizard Sceloporus grammicus that inhabit along an altitudinal gradient at 2500, 3400, and 4100 m and compared some seasonal (spring, summer, and autumn) thermal traits:

1. Body temperature in the field when the lizards were active
2. The relationship between body, air, and substrate temperatures where they were first observed
3. The temperature that they selected in a thermal gradient in laboratory conditions
4. The precision of thermoregulation, the thermal quality of the environment, the effectiveness of thermoregulation, and the Blouin-Demers index
5. The ambient temperatures available during the period of activity (Operative temperature)

Thus, our data suggest that the thermal quality of the environment is low at higher altitudes and in summer, while lizards are capable of modifying their body temperature when they are active in the field and the temperature they select in the laboratory due to the effect of altitude and of the season, according to the requirements they have in each part of the year.