Mean ± SE of male body mass before and after manipulating males by adding color bands during adulthood.

<p>Filled symbols indicate the color of the band that males were allocated and empty symbols refer to the measurement before color bands were added. (A) Males from the wild-type population (W ad), maintained in one large group containing 10 red-banded males (red symbols), 10 green-banded males (green) and 11 un-banded control males (grey); (B) males from the domesticated population (D ad), maintained in groups of two (one red-banded, one green-banded); (C) males from the domesticated population (D ad), changing from the group size of two (“before” shows the same data as the “after” in (B) but with different grouping of individuals) to groups of 10 or 11 males (with about equal numbers of red-banded and green-banded males).</p

Mean ± SE of body mass measured after manipulating males during the juvenile period.

<p>All males were housed in groups of four males with four females during this period, and within each experimental group the four males were either all wearing the same color bands (uni-color; i.e. all green or all red) or there were two males of each color (mixed color). Symbol colors represent the color assigned during the experiment. (A) shows the data for the wild-type and (B) for the domesticated population.</p

Design of the four experiments carried out on males from two populations of zebra finches in comparison to the study by Pariser et al. [25].

(a)<p>Cages were 45 cm high, aviaries were 2 m high.</p

Effect sizes (d ±95% CI) of the color band treatments on (A) male courtship rate and (B) male body mass.

<p>A positive effect size refers to red-banded males obtaining higher courtship rate or mass compared to green-banded males. For individual experiments, the size of the square reflects sample size, and for the overall estimate the diamond marks the mean and the 95% CI. Longitudinal analyses as marked with (L); the remainder are cross-sectional analyses. The experiments in (a) refer to Pariser et al. <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0037785#pone.0037785-Pariser1" target="_blank">[25]</a>, Ratcliffe and Boag <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0037785#pone.0037785-Ratcliffe1" target="_blank">[24]</a> inexperienced birds (1) and experienced birds (2), Gleeson <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0037785#pone.0037785-Gleeson1" target="_blank">[39]</a> individual housing and group housing, Burley et al. <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0037785#pone.0037785-Burley6" target="_blank">[14]</a>, wild-type population (W) of the present study, domesticated population (D) of the present study, juvenile (juv) and adult (ad) birds, with housing in uni-color and mixed color groups, and housing in duos or larger groups; (b) Zann <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0037785#pone.0037785-Zann1" target="_blank">[16]</a> at the start (t1) and end (t2) of the breeding season, Cuthill et al. <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0037785#pone.0037785-Cuthill1" target="_blank">[23]</a> with mass measured at either dawn or dusk, Schuett and Dall <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0037785#pone.0037785-Schuett1" target="_blank">[7]</a>, and others as above.</p

Mean ± SE of male courtship rate (transformed) before and after manipulating males by adding color bands during adulthood.

<p>Filled symbols indicate the color of the band that males were allocated and empty symbols refer to the measurement before color bands were added. (A) Males from the wild-type population (W ad), maintained in one large group containing 10 red-banded males (red symbols), 10 green-banded males (green) and 11 un-banded control males (grey); (B) males from the domesticated population (D ad), maintained in groups of two (one red-banded, one green-banded); (C) males from the domesticated population (D ad), changing from the group size of two (“before” shows the same data as the “after” in (B) but with different grouping of individuals) to groups of 10 or 11 males (with about equal numbers of red-banded and green-banded males).</p

Mean ± SE of courtship rate (square-root transformed seconds of song) recorded after manipulating males with color bands during the juvenile period.

<p>All males were housed in groups of four males with four females during this period, and within each experimental group the four males were either all wearing the same color bands (uni-color; i.e. all green or all red) or there were two males of each color (mixed color). Symbol colors represent the color assigned during the experiment. (A) shows the data for the wild-type and (B) for the domesticated population. The asterisk denotes a significant treatment effect.</p