Thermal Effectiveness and Warming Tolerance in Liolaemus riojanus and L. scapularis

## Overview: This dataset contains field and laboratory thermal data collected from two sister species of psammophilous (sand-dwelling) lizards, *Liolaemus scapularis* and *L. riojanus*, from the Monte desert of Argentina during 2018-2022. The data support analyses of thermoregulatory effectiveness, behavioral buffering capacity, and thermal vulnerability to climate change. Thermal ecology dataset from two sister species of sand-dwelling lizards (Liolaemus scapularis, L. riojanus) from Argentina's Monte desert, 2018-2022. Includes: (1) environmental operative temperatures (n=3,927 records with microhabitat detail), (2) field body temperatures (n=376 individuals), (3) laboratory thermal preferences (n=65), and (4) critical thermal maxima (n=37). Data support analyses of thermoregulatory effectiveness and climate change vulnerability published in [journal]. All datasets include morphological data (SVL, sex) and temporal metadata (date, period, site).## Study Species and Sites: - **Liolaemus scapularis**: Cafayate, Salta Province (26°02'S, 65°53'W) - 4 field trips- **Liolaemus riojanus**: Talampaya National Park, La Rioja Province (29°45'S, 68°00'W) - 6 field tripsBoth species are endemic to sandy habitats in the Monte ecoregion and exhibit specialized sand-burrowing behavior. Sampling occurred during austral spring-summer (October-March) across dry (spring) and humid (summer) climatic periods.## Dataset Components### 1. operative_temperatures.csv (n = 25,215 records)Environmental operative temperatures (Te) measured using temperature dataloggers (iButton DS1921G) housed in physical models mimicking lizard thermal properties. **Key variables**: species, site, field_trip_id, datetime, microhabitat, Te_C (°C), period (dry/humid)**Note**: To replicate manuscript statistics (n=8,405 timestamps), group by datetime and calculate mean(Te_C) across the three microhabitats.### 2. body_temperatures.csv (n = 376 individuals)Field body temperatures (Tb) of active adult lizards measured via cloacal insertion within 20 seconds of capture. Includes morphological data and capture conditions.**Key variables**: individual_id, species, site, date, period, time, sex, SVL_mm, Tb_C (°C)### 3. preferred_temperatures.csv (n = 65 individuals)Laboratory-determined thermal preferences from thermal gradient experiments (1.4 m gradient, 20-60°C range). Individuals were measured at 30-minute intervals for 4 hours. Values represent individual means.**Key variables**: individual_id, species, period, sex, SVL_mm, Tpref_mean (°C), Tset_lower, Tset_upper**Tset definition**: Thermal set-point range (interquartile range, 25th-75th percentiles) representing preferred thermal range.### 4. critical_thermal_maxima.csv (n = 37 individuals)Critical thermal maxima (CTmax) determined via dynamic ramping (0.8°C/min heating rate). Endpoint criterion was loss of righting response accompanied by muscle spasms.**Key variables**: individual_id, species, sex, SVL_mm, CTmax_C (°C)## Data Collection Methods- **Field body temperatures**: Quick-reading digital thermometer (Reed LM-8000, ±0.1°C resolution)- **Operative temperatures**: Temperature dataloggers recording every 10 minutes (0800-2000h)- **Preferred temperatures**: Thermal gradient with 4-hour acclimation + measurement period- **Critical thermal maxima**: Controlled heating with infrared thermometer monitoring## Temporal Coverage- **Years**: 2018-2022- **Seasons**: Dry period (October-December, austral spring); Humid period (January-March, austral summer)- **Daily sampling**: 0800-2000h (GMT-3)## Missing Data- Missing values coded as "NA"- Sex determination not possible for all individuals (based on external morphology)- CTmax sample size limited by animal welfare considerations## Usage Notes1. **Operative temperatures**: Each timestamp has 3 microhabitat records. Aggregate appropriately for your analysis.2. **Preferred temperatures**: Values are individual means from time-series measurements (8 timepoints per individual).3. **Species nomenclature**: Consistent format "L. scapularis" and "L. riojanus" across all files.4. **Coordinates**: Exact GPS coordinates of individual captures excluded to protect populations of endangered L. scapularis. General site coordinates provided in manuscript Methods.## License: CC-BY 4.0## ContactPhD Ana Gabriela Salva ([e-mail])## AcknowledgmentsField research conducted under permits emited by Secretaría de Desarrollo Sustentable del Ministerio de Producción, Trabajo y Desarrollo sustentable of Salta province (Res. N° 552/18; 735/19) and Administración de Parques Nacionales (DRC 366). We thank Viviana Garcia, Gimena Toledo, Jorge Medina for their invaluable assistance during the arduous field data collection.---