Data and scritp for: <b>Comparative analysis of plasma steroid hormone levels reveals lower concentrations in Afrotropical than European temperate zone passerines</b>

<br><b>Description and metadata for:</b>'Kauzál et al.: Comparative analysis of plasma steroid hormone levels reveals lower concentrations in Afrotropical than European temperate zone passerines'Journal: <i>Zoological Journal of the Linnean Society</i>doi: 10.1093/zoolinnean/zlag038Author responsible for the repository:Ondřej KauzálInstitute of Vertebrate BiologyCzech Academy of [e-mail] origin:Study presents original data on plasma concentrations of testosterone (TEST) and baseline and stress-induced corticosterone (CORT) in tropical and temperate passerine species collected by the team of authors, supplemented with life-history data obtained from literature (species fecundity, breeding season, diet, migration distance, elevational ranges and phylogeny).Metadata for the file: kauzal_et_al_2026_plasma_data.txtDescription:A text file containing the individual data used in this study, separated by tab ("\t"). The file contains following variables:Variables:id -- unique identifier of each individualspec.final -- latin species namespecies -- latin species name used by brms modelanimal -- latin species name used by brms modelfamily -- scientific family of a speciessex -- individual sex (m: male; f: female)season -- tropical season of sampling (dry/wet; only tropical species)breeding.range -- breeding zone (tropical/temperate)breeding.status -- breeding cycle information (breeding/non breeding)capture.elevation -- elevation of capture of an individual [km a.s.l.; only tropical species]elevation.ebird -- elevational distribution midpoint of a species [km a.s.l.; only tropical species]t0 -- time since capture to bleeding [min]t30 -- stressor duration [min]nitro.lag -- time since bleeding to deep freezing the sample [hours]catch.sunrise -- the difference between time of capture and sunset for a given day [hours]voice.catch -- usage of playback for capturing an individual (yes/no)mass.field -- body mass of an individual when captured [g]avg.mass -- average body mass of a species [g]g.0 -- measured concentration of baseline glucose [mmol/l]cort.t0 -- measured concentration of baseline CORT [pg/ml]cort.t30 -- measured concentration of stress-induced CORT [pg/ml]test.t0 -- measured concentration of TEST [pg/ml; LOQ for values below limit of detection: see supplementary Material and Methods]migration.latitude -- migration distance [1000km]clutch.size -- mean number of eggs in a single clutchdiet.carnivore -- proportion of animal matter (invertebrates, vertebrates, carcasses) in a diet of a species [%]diet.nectarivore -- proportion of sugar (nectar and fruit) in a diet of a species [%]diet.herbivore -- proportion of plant matter (seeds, leaves) in a diet of a species [%]Data sources:avg.mass -- own databreeding.status; elevation.ebird; g.0 -- Tomášek et al. 2022migration.latitude -- BirdLife International and Handbook of the Birds of the World (2018) (see Material and Methods for its estimation)diet.carnivore; diet.nectarivore; diet.herbivore -- Wilman et al. 2014clutch.size -- Myhrvold et al. 2015 and other sources (see Supplementary information)Metadata for the file: kauzal_et_al_2026_plasma_modelpredictors.txtDescription:A text file containing information about model formulas, predictors, response variables adn dataset of all models used in this study. This dataset is used to batch-generate all the models in this study. The columns are separated by tab ("\t"). The file contains following variables:Variables:response -- Response variable used in the model.predictors -- Predictors used in the model.path -- Path to the directory where results are stored.model.name -- Name of the model generated.hormone dataset -- Dataset used to generate the model.Metadata for the file: horak_2022-knud.treDescription:A phylogenetic tree in NEWICK format generated in Horák et al. (2022) used in this study.CodeIn addition to the two data files, there are R code files in the folder /scripts/ and its subfolders. The files contain all the code used to generate the results in this study. The code is intended to run in the following order:00_start here.Rproj -- starts a new R project and set working directory to the current directory (all further scripts expect that the working directory is set to the directory where all the files are stored)01_data_preparation.R -- data preparation (generates data file used by all later scripts)02_modelling.R -- generation of all models in main text and supplementary inforamtion, comparing models using loo package (uses data file generated by script "01_data_preparation.R")03_plotting.R -- visualisation (uses models generated by script "02_modelling.R")FundingThis study was funded through Czech Science Foundation grants GA17-24782S and GA25-17505S to TA and GA26-22858S to OT.AcknowledgementsWe would like to thank to everyone who helped with the data collection in the field, namely Jaromír Čejka, Marek Brindzák and Kateřina Šimonová. Also, we are very grateful to the Chief of Bokwaongo, Chief of Bakingili and Bokwaongo community for their help with the field work in Cameroon.ReferencesBirdLife International and Handbook of the Birds of the World (2018) Bird Species Distribution Maps of the World. Version 2018.1.Horák et al. (2022). Feather growth and quality across passerines is explained by breeding rather than moulting latitude. Proceedings of the Royal Society B: Biological Sciences 289. https://doi.org/10.1098/rspb.2021.2404Myhrvold et al. (2015). An amniote life‐history database to perform comparative analyses with birds, mammals, and reptiles. Ecology 96: 3109–3109. https://doi.org/10.1890/15-0846R.1Wilman et al. (2014). EltonTraits 1.0: Species‐level foraging attributes of the world’s birds and mammals. Ecology 95: 2027–2027. https://doi.org/10.1890/13-1917.1Tomášek et al. (2022). Latitudinal but not elevational variation in blood glucose level is linked to life history across passerine birds. Ecology Letters: 1–14. https://doi.org/10.1111/ele.14097<i>Editing history:</i><i>Edited on 3rd March 2026: changing filenames (reflecting year of publishing), adding information about journal and doi. No change to data or scripts themselves. </i><br>