Figure legends
Figure 1;
Phylogenetic tree of the 53 bird species for which adult and chick telomere length (TL) and telomere length rate of change (TROC) were collected from published papers on avian telomeres using the TRF methodology. The consensus phylogenetic tree was obtained from BirdTree.org (100 trees) using ape, apTreeshape and caper R packages (see ESM 4).
Figure 2:
Effect sizes (Rho values) and 95% confidence intervals for phylogenetic effects on bird TL variables (Adult telomere length (Adult TL), telomere length rate of change (TROC) and chick telomere length (Chick TL), and the three principal component axes that reflected bird species’ life history traits (PCA 1 - body size , PCA 2 - slow-fast continuum of the pace of life and PCA 3 - post-fledging parental care ). Effects are considered significant when not overlapping zero.
Figure 3:
Adult telomere length (TL, in kb) in relation to life-history axes PC1 (A), PC2 (B) and PC3 (C). Note that none of the relationships turned out to be significant. (Table 2). Dashed lines refer to Pearson’s linear correlation (PC1, r = -0.23; PC2, r = 0.15; PC3, r = 0.04, Table 2). Symbols indicates the distribution of the 13 bird orders. Note that two unadjusted correlations reached significance for Adult TL / PC2: Procellariiformes, r = -0.75, t = -2.18, p = 0.031, n = 8; Passeriformes, r = 0.69, t = 3.32, p = 0.006, n = 14.
Figure 4:
Telomere length rate of change (TROC, in kb / year) in relation to life-history axes PC1 (A), PC2 (B) and PC3 (C). Only THE TROC and PC2 relationship was statistically significant (Table 2). Dashed (non-significant) and plain (significant) lines refer to unadjusted for phylogeny Pearson’s linear correlation (PC1, r = 0.34; PC2, r = -0.54; PC3, r = 0.12, Table 2). Symbols indicates the distribution of the 13 bird orders. Note that all unadjusted correlations reached significance for the Procellariiformes, n = 7; PC1: r = -0.95, t = -6.97, p < 0.001; PC2: r = -0.92, t = -5.06, p = 0.004; PC3: r = -0.79, t = -2.86, p = 0.035.
Figure 5:
Chick telomere length (TL, in kb) in relation to life-history axes PC1 (A), PC2 (B) and PC3 (C). Note that none of the relationships turned out to be significant (Table 2). Dashed lines refer to unadjusted for phylogeny Pearson’s linear correlation (n = 29; PC1, r = -0.20; PC2, r = 0.05; PC3, r = -0.01, Table 2). Symbols indicates the distribution of the 13 bird orders.
Figure 6:
Frequency distributions of phylogenetic (A ) and residual (B ) correlation values produced by the iterations of the multivariate linear models using Monte Carlo methods and Bayesian Markov Chain sampling (MCMC) between TROC and life-history axes of bird life history traits, i.e. PC1 (body size, left panels), PC2 (pace of life, middle panels) and PC3(parental care, right panels). This multivariate model controlled for shared ancestry simultaneously for all variables. Red lines indicate the peak values reported in Table 2 (two last right columns).