Avian eggshell thickness indices and phylogenetic analysis

The data and R scripts used in the Ibis paper entitled "Global diversity and adaptations of avian eggshell thickness indices" by Attard and Portugal 2022 are within the zipped file. A description of each file is provided below. Species eggshell thickness and life history data The excel file "shell_thickness_species_data" contains species-specific eggshell thickness (d) values and all other information (e.g., egg width, egg length, shell mass) from Schönwetter’s Handbuch der Oologie tables. This tab is saved as a csv file for the R scripts. All sources used to extract life-history traits are in the column "source_lifehistory". The "life history sources" tab in the excel file lists all references used to find life-history trait data. R scripts for Phylogenetic Comparative Analysis There are three R scripts that perform perform phylogenetic comparative analysis across all birds in the dataset, and separately for passerines and non-passerines. This includes phylogenetic signal (based on lamdba values) and PGLS. Several supplementary figures are also produced using the script for all birds. R script for figures The R script entitled "R Markdown_Shell thickness figures" contains code to create all remaining figures used in this paper, including phylogenetic trees. Species eggshell thickness phylogeny files: The nexus (nex) tree file (species_shell_thickness_phylogeny_original.nex) contains avian phylogenetic trees constructed online (http://www.birdtree.org) using the primary backbone tree of Hackett et al. 2008. One thousand trees were constructed, and comprise of all species included in this study. The newick (nwk) tree file (species_eggshell_thickness_phylogeny.nwk) is the maximum clade credibility tree generated from the "Rmarkdown_Phylogenetic Comparative Analysis_all birds" script. This tree is used for phylogenetic comparative analysis and to create the phylogenetic tree diagrams in the paper.