Data from: Introduced urban lizards (Podarcis muralis) exhibit environmentally plastic activity patterns and precise behavioral thermoregulation
Data files
Jul 20, 2026 version files 1.76 MB
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FieldData_PodarcisThermalBiology.csv
5.07 KB
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LizardData_PodarcisThermalBiology.csv
14.15 KB
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OTMData_PodarcisThermalBiology.csv
210.59 KB
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PlotTheme.R
1.07 KB
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README.md
5.85 KB
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subset_bySite.R
3.10 KB
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SurveyData_PodarcisThermalBiology.csv
6.63 KB
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ThermalSurveys_Analysis.html
1.44 MB
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ThermalSurveys_Analysis.R
36.98 KB
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ThermalSurveys_Analysis.Rmd
37.54 KB
Abstract
Effective thermoregulation is important for most ectotherms, as body temperature determines the rate of nearly all physiological processes. However, for most organisms, we lack an understanding of which environmental factors affect thermoregulatory behaviors, especially outside of a laboratory setting and over an entire day. Introduced populations of the common wall lizard (Podarcis muralis) in Cincinnati, Ohio are thriving after an introduction almost 75 years ago. To noninvasively quantify daily thermoregulatory behaviors and thermoregulatory effectiveness, we used infrared thermography (a thermal imaging camera) to conduct repeated standardized sampling every 30 min across the lizard’s normal activity period (0800–2000 hours) at multiple urban locations. We also measured air temperature, ultraviolet (UV) radiation, and wind speed, while 3D-printed operative temperature models quantified available temperatures throughout the activity period. Lizard activity varied throughout the day and peaked in the early afternoon. Furthermore, activity patterns were associated with the interaction of temperature and UV radiation intensity, such that predicted activity is greatest at high temperatures when UV is low and at low temperatures when UV is high. Activity was limited by cool environmental temperatures, even on hot days in midsummer. When lizards were active, they thermoregulated precisely and achieved body temperatures closely matching preferred temperatures selected in a laboratory gradient in a previous study. Furthermore, field body temperatures did not vary because of sex, reproductive status, or size. Data on daily activity and thermoregulatory decision-making, especially in an urban habitat, provide valuable insight into how an ectothermic organism integrates multivariate sensory inputs from the environment to make behavioral decisions. The role of environmental conditions in behavioral decision-making is especially relevant in predicting geographical range expansions, particularly in the context of changing urban environments and introduced species.
Dataset DOI: 10.5061/dryad.1ns1rn96n
Description of the data and file structure
The purpose of this study was to determine the abiotic and biotic variables underlying behavioral thermoregulation in Podarcis muralis. To this end, we collected data organized into four files, listed below. The study and data collection took place across six surveys in Cincinnati, Ohio throughout June 2023 to July 2024. Missing data is marked as NA.
Files and variables
"OTMData_PodarcisThermalBiology.csv"
Description: Provides temperature data collected by operative temperature models along with the date, time, and location of their deployment.
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DateTime: Date and time of a temperature observation (Month/Day/Year 12:00AM).
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Ch: Channel a temperature observation was recorded by. (Ch1 = Channel 1, Ch2 = Channel 2, ... , Ch16 = Channel 16).
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Temp: Temperature recorded by operative temperature model (°C).
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Population: Location a temperature observation was recorded in (Aul = Ault Park, Alm = Alms Park, Wal = Walmart).
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"FieldData_PodarcisThermalBiology.csv"
Description: Provides sex and morphological data collected from lizards during capture and release.
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CollectionDate: Date of a lizard's capture and data collection. (Month/Day/Year).
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ID: Identification number given to captured lizard (PmXXX = Recapture identification number).
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Population: Location of a lizard's capture (AUL = Ault Park, ALM = Alms Park, WAL = Walmart).
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Sex: Sex of lizard (F = Female, M = Male, J = Juvenile).
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Gravid: Gravidity of lizard (Y = Yes, N = No, NA = Not Applicable).
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Mass: Mass of lizard (g).
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SVL: Snout-vent length, the distance from the tip of the snout to the posterior end of the anal scale of lizard (mm).
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"LizardData_PodarcisThermalBiology.csv"
Description: Provides information on thermally imaged lizards, including identification data and info to estimate body temperatures collected by FLIR thermal imaging camera.
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Date: Date that thermal image of lizard was taken (Month/Day/Year).
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Population: Location of thermal image (AUL = Ault Park, ALM = Alms Park, WAL = Walmart).
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SurveyTime: What time the survey began when the thermal image was taken (00:00).
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ID: Identification number for lizard in thermal image if it was confirmed it had been captured before (PmXXX = Recapture identification number, UNKN-Population-XXX = No previous identification number assigned).
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PaintID: Paint colors observed on photographed lizard, read from head to tail (G = Green, R = Red, B = Blue, Y = Yellow, W = White, X = Unidentifiable Color) (Ex: WRX = Lizard with a white marking, then a red marking, and then an unknown marking).
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ImageUsed: Number of image, taken from the photo filenames (NA = The thermal image of the lizard had some factor that made it unreliable and data was not collected).
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ThermalImageTb: Body temperature of photographed lizard, averaged from all pixels in the image's region of interest (°C) (NA = The thermal image of the lizard had some factor that made it unreliable and data was not collected).
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ROI: The region of interest. The amount of pixels used to determine body temperature of photographed lizard (NA = The thermal image of the lizard had some factor that made it unreliable and data was not collected).
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Distance: How far away FLIR thermal imaging camera was from photographed lizard (m) (NA = The thermal image of the lizard had some factor that made it unreliable and data was not collected).
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"SurveyData_PodarcisThermalBiology.csv"
Description: Provides collected weather data from each survey period.
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Date: Date that weather data was collected (Month/Day/Year).
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Population: Location of weather data (AUL = Ault Park, ALM = Alms Park, WAL = Walmart).
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SurveyTime: What time the weather data was collected (00:00).
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AirTemp: Temperature of the air during survey (°C).
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RH: Relative humidity of the air during survey (%).
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Wind: Speed of wind at start of survey (m/s).
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UV: Amount of ultraviolet radiation at start of survey (UV Index).
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SolRad: Amount of solar radiation at start of survey (watts/meter^2).
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NumberActive: Number of lizards active at start of survey.
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"ThermalSurveys_Analysis.R"
The main analysis file containing data wrangling, data analysis, key results, and figure output.
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"PlotTheme.R"
Creates an outline for the design of graphs, setting up coloring, text sizes, and graph sizes.
Called from within "ThermalSurveys_Analysis.R"
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"subset_bySite.R"
Splits the thermal data collected for the lizards and operative temperature models based on their site and year of collection.
Called from within "ThermalSurveys_Analysis.R"
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"ThermalSurveys_Analysis.Rmd"
R Markdown version of "ThermalSurveys_Analysis.R". Used to create "ThermalSurveys_Analysis.html".
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"ThermalSurveys_Analysis.html"
Visual summary of code and output of "ThermalSurveys_Analysis.R".
