Seasonality provokes a shift of thermal preferences in a temperate lizard, but altitude does not

1. We compared the mean, limits and breadth of the preferred thermal range (PTR) of two Iberian populations of the lizard Psammodromus algirus separated by 700 m altitude in May and July.2. Seasonality had a pronounced effect on the mean and limits of PTR, but altitude and sex did not. The breadth of PTR remained constant between seasons.3. The observed seasonal shift in PTR facilitated thermoregulation in May but not in July.4. The location, breadth, and seasonal shift of PTR may be a result of the neurohormonal effects of the photoperiod and the functional implications of body temperature for muscle-contraction speed.