Statistical analysis.

<p>We investigated the association between the presence of <i>Salmonella</i> Typhimurium on the eggshell of blue and great tits and the egg volume, clutch size, number of nestlings, number of fledglings and SMI. The results are represented as the estimate ± standard deviation (stdev), degrees of freedom (d.f.), t-value and P-value.</p

Phage and MLVA typing of <i>Salmonella</i> Typhimurium.

<p>Shown are the phage types and MLVA profiles of the seven <i>Salmonella</i> Typhimurium isolates targeting 5 loci.</p

Health and reproductive parameters of blue and great tits.

<p>Shown are the mean health and reproductive parameters ± stdev, including SMI, egg volume, clutch size, number of nestlings and number of fledglings, of blue and great tits in nests containing an egg with a <i>Salmonella</i> negative or positive eggshell.</p

Map of the study plots showing the distribution of <i>Salmonella</i> Typhimurium.

<p>Shown are the study plots used to investigate <i>Salmonella</i> Typhimurium presence in blue and great tit nest boxes. Negative plots are indicated by grey dots, plots where <i>Salmonella</i> was found on the eggshell are represented by yellow dots and plots with nestlings carrying <i>Salmonella</i> IgY antibodies are depicted by blue dots.</p

IgY antibody assessment in blood of great tits.

<p>Indicated are fledglings having anti-<i>Salmonella</i> antibodies (IgY) in their blood at day 14–15.</p

Minimum spanning tree based on MLVA data.

<p>Shown is a minimum spanning tree calculated for the MLVA profiles of the seven <i>Salmonella</i> Typhimurium isolates of blue and great tits, compared with 3239 <i>Salmonella</i> Typhimurium human isolates, regardless of phage type, in Belgium over the period of 2010–2016.</p

Reproductive parameters and SMI of blue and great tits originating from a nest containing a <i>Salmonella</i> positive eggshell.

<p>Reproductive parameters and SMI of blue and great tits originating from a nest containing a <i>Salmonella</i> positive eggshell.</p