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Description

This study is a broad-scale comparative analysis of the association between avian glucose concentration and nutritional types (trophic guilds) and how this variation is related to the longevity of bird species. To explore this relationship, we applied phylogenetically controlled PGLS and MCMCglmm models while controlling for the allometric relationship between body weight and blood glucose concentration. We collected glucose concentration data from 202 bird species from scientific publications, and we also collected body weight data of these species. We classified the bird species into seven different trophic guilds (with equivocal cases having an alternative classification). We also used an independent trophic classification (AVONET trophic niches, see below). The dataset also consists of longevity data of 159 bird species with references.

Authors:

Endre Z. Szarka Department of Evolutionary Zoology and Human Biology, University of Debrecen, Debrecen, Hungary Juhász-Nagy Pál Doctoral School of Biology and Environmental Sciences, Debrecen, Hungary

Ádám Z. Lendvai Department of Evolutionary Zoology and Human Biology, University of Debrecen, Debrecen, Hungary

Contact:

Endre Z. Szarka, email: szez77@gmail.com{.email}

File list and descriptions:

Data_collection.xlsx

This file provides data used for the analyses. The file contains four different sheets: Main_dataset, Longevity_dataset.1, Longevity_dataset.2, References.

Main_dataset

This file consists of all collected blood glucose concentration data for 202 bird species, along with additional information, primary and alternative classifications of trophic guilds, and body weight data for the species, including descriptions of how they were obtained. This sheet contains the following columns:

• Scientific name: Scientific names of the species, occasionally modified to the correct synonym found on Birdtree.org.
• Subspecies name: Scientific names of the bird subspecies. ‘Undefined’ means not reported in the study.
• Common name: Common names of bird species. ‘Undefined’ means not reported in the study.
• Taxonomic order: Taxonomic orders of the bird species.
• Blood component: Blood components that were used for the determination of glucose concentration.
• Glucose concentration (mmol/l): Collected glucose concentration data expressed in units of mmol/L.
• Glucose concentration (mg/dl): Collected glucose concentration data expressed in units of mg/dl.
• Number of sample (n): Number of samples used for determining the collected glucose concentration data.
• Origin: This refers to the blood glucose concentration of individuals measured either in the wild (free-living) or in captivity (captive).
• Sex: Sexes of individuals. ‘Undefined’ means not reported in the study.
• Age: Age of individuals.
• Age comments: In certain cases, some comments are required. This column contains those comments.
• Handling time (min.): Elapsed time between capture and blood collection, expressed in minutes.
• Season: Annual seasons of collected glucose concentration data. The given months are categorised into the four annual season categories with considering the northern and southern hemispheres (in the Northern hemisphere and close to the Equator (e.g. Galapagos Islands); summer: June-August, autumn: September-November, winter: December-February, spring: March-May, in the Southern hemisphere: summer: December-February, autumn: March-May, winter: June-August, spring: September-November). Data whose measurement period included more seasons (e.g. May-July) were considered combined. ‘Undefined’ means it could not be determined.
• Season comments: Information from the literature on the basis of which the seasons were determined.
• Life history stage: This column consists of life history stages of individuals. We considered as ‘undefined’ the life-history stages, which were not clearly defined (e.g. ‘non-laying’, ‘non-breeding’) or were expressed only in months (e.g. ‘sample was taken in July’) in the study. If the glucose concentration data referred to multiple life-history stages and was reported as pooled data (e.g. annual mean), we also considered the life-history stage as ‘undefined’. We classified all of life-history stages into four main categories. The ‘pre-breeding’, ‘courtship’, ‘mating’, ‘laying’, ‘incubation’, and ‘parental care’ were merged into the breeding life-history stage. The different stages of moulting (‘pre-moult’, ‘mid-moult’, ‘post-moult’) were merged into the moulting life-history stage. The wintering life-history stage refers to the resting period of both resident and migratory birds. The migration life-history stage included spring and autumn migration periods.
• Life history stage comments: Information from the literature on the basis of which the life history stages were determined.
• Additional comments: Additional information from the scientific literature associated with the collected glucose concentration data.
• References of glucose concentration data: A reference list of scientific publications used for glucose concentration data collection is provided. The complete list of scientific publications can be found in the “References” sheet.
• Trophic guilds (primary classification): Seven trophic guild categories of species according to primary classification.
• Trophic guilds (alternative classification): Seven trophic guild categories of species according to alternative classification.
• Diet and foraging details: The detailed diet of the species, on the basis of which the trophic guild classifications were made based on the description of Birds of the world [1].
• Body weight (g): Body weight data assigned to the given glucose concentration data, expressed in units of grams.
• Body weight determination: Details on how body weight data were determined.

Longevity_dataset.1

Longevity data of seven bird species, derived from De Magalhães & Costa [2].This sheet contains the following columns:

• Scientific name: Scientific name of the species, occasionally modified to the correct synonym found on Birdtree.org (http://birdtree.org/).
• Longevity (years): Longevity data of bird species, expressed in years.
• Origin: This refers to the longevity data measured either in the wild (free-living) or in captivity (captive).
• Source: Source of longevity data.

Longevity_dataset.2

Longevity data of 152 bird species, derived from Valcu et al. [3]. This sheet contains the following columns:

• Scientific name: Scientific name of the species, occasionally modified to the correct synonym found on Birdtree.org (http://birdtree.org/).
• Longevity (years): Longevity data of bird species, expressed in years.
• Origin: This refers to the longevity data measured either in the wild (free-living) or in captivity (captive).
• Sources: Sources of longevity data.

References

Reference list of all data sources that can be found in the Data_collection.xlsx file.

Analysis_script.R

This file provides R codes of analyses and figures, containing all steps and sections of the total analysis procedure. The steps of analysis are commented, and the positions of the main sections are provided with the corresponding sequence number at the beginning of the script. The script consists of the following main contents:

• Consensus tree creator function for phylogenetically controlled analysis using the Tree.nex file.
• Repeatability estimation model in package ‘rptR’ to explore the repeatability of intraspecific variation of glucose concentration.
• Phylogenetically controlled PGLS models that were used to explore the relationship between glucose concentration as the dependent variable and trophic guilds as the explanatory variable while controlling for log-transformed body weight. This analysis comprised three individual PGLS models, and was repeated with alternative trophic guilds and AVONET [3] trophic niche classification.
• Phylogenetically controlled PGLS models that were used to explore the relationship between longevity as the dependent variable and glucose concentration as the explanatory variable while controlling for log-transformed body weight and trophic guilds. This analysis comprised five individual PGLS models.
• Calculating eta-squared values as effect size.
• Phylogenetically controlled MCMCglmm models that were used to explore the relationship between glucose concentration as the dependent variable and trophic guilds as the explanatory variable, while controlling for log-transformed body weight and confounding factors including blood component, origin, sex, season, and life history stage. This analysis comprised five individual MCMCglmm models.
• Phylogenetically controlled MCMCglmm models that were used to explore the relationship between longevity as the dependent variable and glucose concentration as the explanatory variable, while controlling for log-transformed body weight and origin of individuals as confounding factors. This analysis comprised three individual MCMCglmm models.
• A short analysis involving handling time.
• The numbers of taxonomic orders, species, and collected glucose concentration samples per different trophic guild and AVONET trophic niche [4] classifications.
• Figures of the article and the supplementary material.

Tree.nex

Phylogenetic tree file containing 202 bird species for generating consensus tree. This file was generated by using 1000 random trees based on the ‘Ericson all species: a set of 10000 trees with 9993 OTUs each’ backbone from the BirdTree.org (http://birdtree.org/) platform.

Additional datasets

As a part of the analyses, we also used the AVONET trophic niche classification [4], which was derived from the following source: AVONET supplementary dataset 1. (https://figshare.com/s/b990722d72a26b5bfead)

Information sources

Software and codes

RStudio is required to run Analysis_script.R. This script was created by using version 4.1.2.

References of README.md file

• [1] Birds of the World. 2022 Edited by S. M. Billerman, B. K. Keeney, P. G. Rodewald, and T. S. Schulenberg. Cornell Laboratory of Ornithology, Ithaca, NY, USA. See https://birdsoftheworld.org/bow/home.
• [2] De Magalhães JP, Costa J. 2009 A database of vertebrate longevity records and their relation to other life-history traits. J. Evol. Biol. 22, 1770–1774. (doi:10.1111/j.1420-9101.2009.01783.x)
• [3] Valcu M, Dale J, Griesser M, Nakagawa S, Kempenaers B. 2014 Global gradients of avian longevity support the classic evolutionary theory of ageing. Ecography 37, 930–938. (doi:10.1111/ecog.00929)
• [4] Tobias JA et al. 2022 AVONET: morphological, ecological and geographical data for all birds. Ecol. Lett. 25, 581–597. (doi:10.1111/ele.13898)