Sampling of abiotic and biotic parameters

We sampled abiotic and biotic predictors in SOM on July 17th, in FOR on July 18th, and in CAN on July 19th in the middle of each of the 4 × 4 m plots. In order to reduce the effect of rainfall on abiotic parameters, which could potentially result in differences among populations, we sampled populations at least 4 days after the last rain. For each plot, we recorded the percentage covered by rocks, bare soil, herbs, and shrubs (N = 165 at CAN and SOM; N = 242 at FOR; Table S1) since vegetation structure determines the availability of hides and places for thermoregulation in lizards (e.g., Jácome‐Flores et al. 2015; Valenzuela‐Ceballos et al. 2015), including the common lizard (Bauwens and Thoen 1981; Van Damme et al. 1987). We measured proportions following the “point quadrat” method (Henderson 2003). Soil moisture, which is an important factor affecting growth, energetic requirements, behavior, and space use in the common lizard (Grenot et al. 1987; Lorenzon et al. 1999), was measured by drilling out a “soil core” of standard size (10 cm depth). Right after extraction, we stored the soil core in a ziplock plastic bag, to prevent loss of water. In the laboratory, the core's mass was measured, and the bag opened, put into an oven, and dried at 90°C for 4 days. Previous tests showed that the dry weight stabilized after 2 days and did not change from day 3 to day 4 (personal observations). Soil moisture was calculated as the difference between fresh and dry weights and corresponds to water per volume (Table S1). Soil moisture represents all types of moisture (e.g., moisture provided by fog, rain, and hydrologic idiosyncrasies of the locations) and it reflects the hydrologic conditions to which lizards are exposed. We measured soil temperature in the drill hole, right after extraction of the soil core, at a depth of 10 cm using a Fluke 50 thermometer (Fluke Corporation, Everett, Washington) with accuracy ± 0.3°C (Table S1). Temperature was recorded after 30 sec (i.e., after stabilization of the thermometer) and it reflects temperature accumulated by insolation and air temperatures, and thus thermoregulatory conditions of lizards (Huey and Slatkin 1976), a parameter that is crucial for ectotherms.