DOI: 10.5061/dryad.tdz08kq31
title: Best of both worlds: Acclimation to fluctuating environments confers advantages and minimizes costs of constant environments

description: Thermal acclimation is often considered critical in organismal responses
 to novel thermal conditions. Our understanding of the physiological
 implications of acclimation is largely derived from lab studies with
 simplified thermal regimes that fail to account for any variation that
 animals would experience naturally (i.e. diel variation). As such,
 constant temperature acclimation experiments may produce a flawed
 understanding of acclimation in the wild. To fill this gap, we acclimated
 lizards (Amphibolurus muricatus) under three thermal regimes (Hot
 Constant, Cold Constant and Alternating) and compared their physiological
 responses (Metabolic Rate, Sprint Speed, Thermal Preferences and Thermal
 Limits). We found that animals maintained constantly at hot temperatures
 (preferred temperature, 35°C) gained sprint performance increases, not
 seen in those maintained constantly at cold temperatures (20°C), yet
 suffered costs to growth (in younger animals) and maintenance (mass loss
 in older animals). Animals maintained at alternating temperatures (12 hr
 20°C; 12 hr 35°C) had performance benefits matching animals in the hot
 treatment, without experiencing reductions in juvenile growth and adult
 mass. Animals acclimated under hot temperatures showed a significant lower
 preferred and voluntary maximum temperatures compared to animals
 acclimated under a cold temperature regime. We found no impact of
 acclimation treatment on behavioural thermal limits or Standard Metabolic
 Rate. Overall, we show that alternating between access to preferred
 temperatures and having periods of energetic rest confer the greatest
 benefits for our animals. These results highlight the importance of
 natural body temperature variation for enhancing overall ectotherm
 performance and physiology, and the costs of novel thermal environments
 that fail to provide this variation.
description: Data was collected using standard methods of closed system
 respirometry, sprint performance, thermal preferences and
 limits.  Processed in Kinovea (sprint), Warthog (SMR),
 Excel (Thermal Preferences).  Data wrangling and analysis in R.
description: # Best of both worlds: Acclimation to fluctuating environments confers
 advantages and minimizes costs of constant environments
 Dataset contains
 information on lizards that underwent three acclimation treatments (Hot,
 cold, fluctuating) and presents phenotyping data for metabolic rate and
 sprint performance across five temperatures as well as thermal preferences
 and behavioural thermal limits. Animals were found to shift phenotypes in
 response to treatment with animals under fluctuating regimes having the
 benefits of accessing hotter temperatures with lower putative costs. The
 attached R files contain code to perform the analysis presented in the
 manuscript. ## Description of the data and file structure Methodological
 Information \========================== \* Methods of data
 collection/generation: see manuscript for details Description of the data
 and file structure \========================== File Summary \* 4 Files in
 total, 3 .csv files and 1 RMD. \- best_of_both_worlds_data_FE_20072023.csv
 \- meta_best_of_both_assay_times.csv \- sprint_assay_order_check.csv \-
 Best_of_both_worlds_revised_final.Rmd File/Folder Details
 \=================== Details for: best_of_both_worlds_data_FE_20072023.csv
 \--------------------------------------- \* Description: Primary dataset
 used for analysis including all physiological phenotyping data and
 experimental information. \* Format(s): .csv \* Dimensions: 40 rows x 69
 columns \* Variables: * ref : a reference number for each line *
 animal.id: animal identification number * batch: animal experimental block
 number (1 - 12) * treatment: Animal treatment group; 35.constat = Hot
 Constant, 20.constat = Cold Constant, 35.20.flip = Alternating. See
 manuscript for more details. * age.class: Age of animals at time of
 experiment. See Manuscript for details of age class breakdown. * sex:
 genetic sex; F = female; M = male * start.mass.g.: Mass prior to
 acclimation treatment in grams * metabolism.mass.g.: Mass of animals when
 undergoing metabollic assays in grams. * home.cage: Housing outside of the
 experimental treatments that animal where animal was housed. *
 acclimation.start: Start date of acclimation treatment *
 acclimation.finish: finish date of acclimation treatment *
 metabolism.date: Date of metabolism assay * sprint.1.date: Date of first
 sprint assay * sprint.2.date: Date of second sprint assay *
 thermal.preferance.date: Date of thermal preference assay *
 metabolism_chamber_size: Size of metabolic chambers (ml) used for
 different sized lizards * metabolism.15: Rate of C02 produced (in ml per
 minute) by animals at 15 degrees Celsius * metabolism.22: Rate of C02
 produced (in ml per minute) by animals at 22 degrees Celsius *
 metabolism.29: Rate of C02 produced (in ml per minute) by animals at 29
 degrees Celsius * metabolism.34: Rate of C02 produced (in ml per minute)
 by animals at 34 degrees Celsius * metabolism.39: Rate of C02 produced (in
 ml per minute) by animals at 39 degrees Celsius * sprint.max.15: Maximum
 sprint speed of lizards (m/s) at 15 degrees Celsius * sprint.max.22:
 Maximum sprint speed of lizards (m/s) at 22 degrees Celsius *
 sprint.max.29: Maximum sprint speed of lizards (m/s) at 29 degrees Celsius
 * sprint.max.34: Maximum sprint speed of lizards (m/s) at 34 degrees
 Celsius * sprint.max.39: Maximum sprint speed of lizards (m/s) at 39
 degrees Celsius * Tpref: Preferred temperature range of lizard calculated
 as the median of all values recorded whilst in the thermal gradient *
 tpref_mean_of_qrt_range: Preferred temperature range of lizard calculated
 as the median of all values within the 1st and 3rd quartile of values
 recorded whilst in the thermal gradient. * TSet: The select temperature
 range calculated as the range between the 1st and 3rd quartile of values
 recorded whilst in the thermal gradient. * VTmin: The single lowest value
 in degrees Celsius recorded in the thermal gradient for each animal. *
 X25Quart: The 1st quartile of values for each animal from temperature
 records in the thermal gradient. * X75Quart: The 3rd quartile of values
 for each animal from temperature records in the thermal gradient. * VTmax:
 The single highest value in degrees Celsius recorded in the thermal
 gradient for each animal. * Tpant: The value in degrees Celsius at which
 an animal began to pant. * Escape.Temp: The value in degrees Celsius at
 which an animal began to to display escape behviour from heat source (See
 manuscript) * tpant.valid: If the assay met criteria for inclusion y =
 Yes, n = no. See manuscript for inclusion details. * thermal.pref.valid. :
 If the assay met criteria for inclusion y = Yes, n = no. See manuscript
 for inclusion details. * comment.metabolism: Comments on the metabolism
 assay * comment.sprint: Comments on the sprint assay * comment.thermal:
 Comments on the thermal assay Note: NA values represent an absence of data
 due to equipment failure, failing to meet inclusion criteria (e.g. animals
 would not run for sprint assay) or unplanned researcher absence. Refer to
 manuscript for further details. Details for:
 meta_best_of_both_assay_times.csv \---------------------------------------
 \* Description:Dataset used for supplementary analysis to validate no
 signficant effects of circadian rhythm on measured metabolic rates. See
 supplementary materials of manuscript for detailed methods. \* Format(s):
 .csv \* Dimensions: 61 rows x 7 columns \* Variables: * batch: animal
 experimental block number (1 - 12) * date: Date of metabolism assay *
 temperature: Temperature of assay in degrees celsius *
 measurement_time_24hr: Time of day that measurement occured in 24hr time *
 measurement_time_12hr: Time of day that measurement occured in 12hr time
 with AM and PM. * order : THe order of assay temperatures, with 1 = first
 assay and 5 = final assay. * after_sunset: If measurements occured after
 sunset (y = yes, n = no). See supplemntary material details about
 determining sunset times. Details for: sprint_assay_order_check.csv
 \--------------------------------------- \* Description:Dataset used for
 supplementary analysis to validate no signficant effects of exhaustion on
 lizard sprinting performance. See supplementary matrials of manuscript for
 detailed methods. \* Format(s): .csv \* Dimensions: 59 rows x 5 columns \*
 Variables: * batch: animal experimental block number (1 - 12) *
 temperature: Temperature of assay in degrees celsius * assay_day: Wheather
 tempeartures were assayed on the first day =1, or the second day = 2. *
 day_order: The order of temperatures assayed on each assay day. 1 = first
 temperature assayed that day, 2 = Second temperature assayed that day, 3 =
 Third temperature assayed that day. * total_order: The total order across
 both days of temperature assays. ## Sharing/Access information All data
 was derived from experimental procedures and not present on other public
 repositories. ## Code/Software Details for:
 Best_of_both_worlds_revised_final.Rmd
 \--------------------------------------- \* Description: Code used to
 perform the analysis presented in the manuscript including the generation
 of thermal performance curves (TPCs) and subsequent analysis. \*
 Format(s): .RMD \* Version: Run in R v. 4.0.2 \* Required Packages: See
 RMD file for all packages not included in base R that are required to
 repeat the analysis.