Univariate results of the percentage of variance explained (R²) by each predictor variable in the three PCA axes.

<p>Univariate results of the percentage of variance explained (R²) by each predictor variable in the three PCA axes.</p

Antimicrobial activity rate.

<p>Variation in the number of symbiotic colonies isolated from hoopoe’s uropygial gland secretion that presented antagonistic activity against indicator bacteria.</p

Intensity of antimicrobial activity.

<p>Variation in the inhibitory intensity against each indicator strain by symbiotic bacteria isolated from the uropygial gland secretion of hoopoes. (SA: <i>S. aureus</i>; ML: <i>M. luteus</i>; LM: <i>L. monocytogenes</i>; LL: <i>L. lactis</i>; LI: <i>L. innocua</i>; BL: <i>B. licheniformis</i>; EF: <i>E. faecium</i>; S47: <i>E. faecalis</i>). Intensity of antagonistic activity: 0 (no halo), 1 (ring width <1 mm), 2 (ring width = 1–2 mm), 3 (ring width = 3–4 mm), and 4 (ring width >4 mm.).</p

Taxonomic position of the OTUs detected in the uropygial secretion of female and nestling hoopoes.

<p>Taxonomic position inferred for the OTUs detected in the uropygial secretion of female and nestling hoopoes by several different molecular methods. When the sequences were not clearly included within a genus in the trees, the genus most closely related to the sequence is given in parentheses (see Figs <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0139734#pone.0139734.g003" target="_blank">3</a> and <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0139734#pone.0139734.g004" target="_blank">4</a>).</p><p>Taxonomic position of the OTUs detected in the uropygial secretion of female and nestling hoopoes.</p

Frequency of appearance of ITS OTUs in wild and captive hoopoe females.

<p>Comparison of the frequency of appearance of the five most prevalent bands (sequenced from RISA gels) between the uropygial secretions of wild hoopoe females and females maintained in captivity.</p><p>Frequency of appearance of ITS OTUs in wild and captive hoopoe females.</p

Consensus trees with the taxonomic position of the different bacterial OTUs (ITS) detected in hoopoe uropygial secretions by sequencing the ribosomal intergenic spacer.

<p>Panels A and B include OTUs grouped according to each of the two subregions found within the ribosomal intergenic spacer. Labels in nodes indicate the bootstrap mean probability for each clade after 100 repetitions.</p

PCoA analysis of captive and wild hoopoe female samples.

<p>The PCoA shows sample grouping by similarities in OTU composition. Samples from captive (red) and wild (blue) female hoopoes cluster separately. The percentage of variation explained by the plotted principal components (PC) is indicated in parentheses.</p

Consensus tree with the taxonomic position of the different bacterial OTUs detected in hoopoe uropygial secretions by sequencing the 16S rDNA.

<p>Labels in nodes indicate the bootstrap mean probability for each clade after 100 repetitions.</p