Schematic representation of the olfactometric device used.

<p>A focal female was introduced into the central chamber and exposed to scent-carrying air flowing in (solid arrows) from the choice chambers. Odour donor nestlings were hidden from the focal female's view behind a dense plastic mesh (fine cross hatching). A choice was scored when the female entered one of the choice chambers after opening the doors (dotted arrows).</p

Number of females choosing their own or a foreign nestling scent.

<p>Number of female spotless starlings that chose the side of the chamber containing the scent of their own nestling or the scent of a foreign nestling (p = 1.00), when a) nestlings were 5–6 day old and have the uropygial gland closed or b) when nestlings were 12–14 day old and have the uropygial gland open.</p

Results of linear mixed models examining variables of chick size in nests moved to high risk sites close to sparrowhawk nests and nests moved to lower risk sites away from sparrowhawk nests.

<p>Results of linear mixed models examining variables of chick size in nests moved to high risk sites close to sparrowhawk nests and nests moved to lower risk sites away from sparrowhawk nests.</p

Results of linear mixed models examining variables of maternal condition in nests moved to high risk sites close to sparrowhawk nests and nests moved to lower risk sites away from sparrowhawk nests.

<p>Results of linear mixed models examining variables of maternal condition in nests moved to high risk sites close to sparrowhawk nests and nests moved to lower risk sites away from sparrowhawk nests.</p

Metadata

Dataset used in this manuscript: results of the experiment and field measures. Abbreviations: 0, 120, 480 h (weight): concentration of oligopeptides at 0, 120 and 480 hours of the experiment. Data are corrected by the weight of each feather piece

Experimental design of artificial and natural nests.

<p>Experimental protocols designed for exploring the effects of feathers and aromatic plants as nest materials on bacterial loads on spotless starling eggs (A) and on quail eggs in non-incubated nests (B). Numbers within the tables indicate sample sizes of different experimental treatment for 2012/2013 study years.</p

Among years variation in nest feathers and bacteria.

<p>Among years variation in nest feathers and bacteria.</p

Influence of experimental treatments on nest lining feathers and aromatic plants.

<p>Influence of experimental treatments on nest lining feathers and aromatic plants.</p

Results of mesophilic bacterial load along incubation (variation between day 3 and day 12).

<p>Average values of eggshell mesophilic bacterial growth (± 95% CI) on starling eggshells in relation to feathers’ experimental treatments (unpigmented, pigmented or without feathers) in 2013 (A, D). The associations of eggshell mesophilic bacterial growth with number of pigmented (B) and unpigmented (C) feathers in starling nests in 2012 are also shown. Figure only shows the most relevant associations detected.</p

Results from Repeated Measures ANOVAs explaining mesophilic bacterial loads on quail eggshells.

<p>Results from Repeated Measures ANOVAs explaining mesophilic bacterial loads on quail eggshells.</p