DOI: 10.5061/dryad.44j0zpcp0
title: Data from: Trophic guilds differ in blood glucose concentrations: A phylogenetic comparative analysis in birds

description: Glucose is a central metabolic compound used as a source of energy across
 all animal taxa. There is high interspecific variation in glucose
 concentration between taxa, the origin and the consequence of which remain
 largely unknown. Nutrition may affect glucose concentrations because
 carbohydrate content of different food sources may determine the
 importance of metabolic pathways in the organism. Birds sustain high
 glucose concentrations that may entail the risks of oxidative damage. We
 collected glucose concentration and life history data from 202 bird
 species from 171 scientific publications; classified them into seven
 trophic guilds and analysed the data with a phylogenetically controlled
 model. We show that glucose concentration is negatively associated with
 body weight and is significantly associated with trophic guilds with a
 moderate phylogenetic signal. After controlling for allometry, glucose
 concentrations were highest in carnivorous birds, which rely on high rates
 of gluconeogenesis to maintain their glycemia and lowest in
 frugivorous/nectarivorous species, which intake carbohydrates directly.
 However, trophic guilds with different glucose concentrations did not
 differ in lifespan. These results link nutritional ecology to physiology
 and suggest that at the macroevolutionary scale, species requiring
 constantly elevated glucose concentrations may have additional adaptations
 to avoid the risks associated with high glycemia.
description: # Trophic guilds differ in blood glucose concentrations: A phylogenetic
 comparative analysis in birds --- ## 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](mailto: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/](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/](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/](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](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](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](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](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](doi:10.1111/ele.13898))